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Lowrider
01-28-2013, 10:51 PM
Has anyone seen the plans for the Bearhawk LSA? It doesn't look Cubish but it is pretty light. Just wondering if there are lessons to be be learned from the design?

Inquiring minds and all that....

knucles
01-28-2013, 11:07 PM
Has anyone seen the plans for the Bearhawk LSA? It doesn't look Cubish but it is pretty light. Just wondering if there are lessons to be be learned from the design?

Inquiring minds and all that....

Heard thru some friends that it is a nice plane. I did look at it but am waiting for my supercub kit now. After exploring different planes in this catagory , i decided the best for me is a 2200 gross supercub. I have built many planes , mostly high performance but i am really looking forward to this project.

Bugs66
01-28-2013, 11:11 PM
Lowrider, why not just build a Cub?

Lowrider
01-28-2013, 11:20 PM
Bugs,

I am, just looking for innovative ideas to put in it. I'm going to build to LSA gross so I'm just trying to find ways to save weight or anything else that may be a good addition. The limited info on the Bearhawk site says it is a new design so maybe there is something to be learned. Like your site....I learn every time I visit it!!!

I bought a bunch of tube and Carlson spars so I'm getting started pretty soon....but still learning.

BTW, I sold my house in MD and will be full time in Sandpoint by mid Feb or so and will take you up on your offer to drop by some day.

Bugs66
01-29-2013, 12:54 AM
Sounds good!

courierguy
01-29-2013, 02:01 PM
A big ass wing for a 700+ lb plane works every time. 175 sq I think.

Lowrider
01-29-2013, 02:04 PM
Yes Sir!! Should float like a leaf.

qsmx440
01-29-2013, 03:39 PM
Yes Sir!! Should float like a leaf.

My Sprint has 156 sq/ft and TO weight runs about 500# and fly's at 20 mph. You don't want to have any wind, gusts, wakes etc. around unless you enjoy negative adrenalin rushes. You can have to much of a good thing or be careful what you wish for!
This brings up a question. Anyone with a super light aircraft add ballast when solo? A cub clone at 1000# T.O. weight has got to be a handful in any gusting wind.

7shannon
01-31-2013, 03:06 PM
Lowrider,
I am building an experimental cub in Deer Park, WA, about 50 miles from Sandpoint. I too am building within the limits of LSA. Fuse and tail pretty far along and just started wings. come by anytime!
Kevin

Lowrider
01-31-2013, 07:17 PM
Kevin,

I'll drop by once I get settled in Sandpoint. I'd love to see your project and thanks for the invite!!

DavePA11
02-01-2013, 07:40 PM
Here it what it looks like for those who haven't seen one:

10134

Spec sheet:
10135

Lowrider
02-02-2013, 07:37 PM
I had a long talk with Bob Barrows last week about the LSA and came away with a positive enough feeling that I bought a set of his plans which arrived today. I have not looked at them in great detail yet but they seem to be very much Cub like in the fuselage except for the full length top longerons that run to the top of the wings giving it the straight line back to the horizontal stabalizer. The biggest differance of course is the metal wing with flush rivets and a single strut. Bob says that's what accounts for the 20-30 mph speed advantage over the Cub at cruise on a C 85-8. With no flaps it stalls at <30 mph so he saw no reason for flaps and saved ~40 lbs. It is designed to 1500 gross and can be set up at 1320 for LSA with some extra margin of safety built in to the design. Cruising on 4 gph at 100 mph is appealing. Bumping it to 125 mph runs 6 gph and with 30 gals that gives pretty good range.

The interior seems to be a fair amount bigger width and height wise and about the same length as a Cub. The view is pretty good in the back and appears to be good up front as well. Bob says you can see over the nose pretty well. I told him tthe ground/prop clearance worried me off airport and he said you can lengthen the legs and run up to 29" tires to get really good clearance. I'm still looking at the suspension but it appears to be the same as tbe one used on the full size Bearhawk which I beleive has been used successfully for a number of years.

I remember how much fun I had bucking rivets on my RV-4 but a slick smooth wing will certainly make it worthwhile in cruise. All in all it looks like a pretty nice airplane and maybe simpler to build...jury is still out on that one.

Tim
02-02-2013, 10:21 PM
Are any flying yet ?

Lowrider
02-02-2013, 10:30 PM
As far as I know only the one built by Bob. My plans are SN: 32 so I suppose there aren't many out there. Funny thing though...they are dated in 2004.

irishfield
02-02-2013, 10:32 PM
Don't be fooled... flush rivets are not faster on anything under 120 mph. In fact the second Murphy SR2500 was about 8 to 10 mph SLOWER with flush riveted wings vs the originals normal dome rivets. Consider all those little bumps as vortex generators and save yourself the heartache of dimpling or countersinking all those holes. The only speed increase over the cub would be attributed to the single strut and 1/2 the drag that this offers.

skywagon8a
02-03-2013, 06:55 AM
The only speed increase over the cub would be attributed to the single strut and 1/2 the drag that this offers.
And perhaps an airfoil with less drag?

courierguy
02-03-2013, 10:25 AM
The gear is less draggy also. Probably 5 mph right there.

Cub junkie
02-03-2013, 11:40 AM
Since this is a cub board I won't go into the attributes of the new Bearhawk LSA but it seems to have picked up steam fast in new builders, more so than the Patrol. Lowrider's plan set numer is 32. The plans have only been offered for about six months, when I bought my Patrol plans (set #28) they had been on the market two years. The wings are labor intensive but not very complicated. The cabin is roomy and long so those long in leg would appreciate that. There will be pre welded kits available soon but if you like welding and fabrication then any of Bob's designs are for you. I think the ideal engine would be a C-90 but would like to see a Rotax 912 on one. I think a realistic empty wt. on one with minimum elec and a small continental would hit around 775-795, about what a homebuilt PA11 would be. Like a cub fuselage the airplane can be built with a left door. I'm way too deep into my Patrol project to start over but if and when I do the sport pilot deal it would be an airplane to consider. I wouldn't try to convince any cub purists to switch over, especially on the biggest cub board on the internet. Always good to see new designs that are worthy of a look.

Edit: I don't know why that smiley face is there, I didn't put it in and I'm not a smiley face kind of guy. I tried to edit and delete it but it didn't take. Was meant to say set #28.

DavePA11
02-03-2013, 12:06 PM
Junkie - I'd like to hear about the attributes of the Bearhawk LSA. There is no issue with posting information like this on a SuperCub forum...

Longwinglover
02-03-2013, 12:49 PM
When the number 8 and the ) are put next to each other the computer recognises that as the Smiley with sunglasses on just as ; with - and ) is a wink.

John Scott

courierguy
02-03-2013, 01:53 PM
The 912s ( geared 100 horse) would weigh a bit LESS then the A-65 while offering very similar burns. My T-craft and my current 912 bird just about identical there, except the Rotax pulls like a strongO-200.

Tim
02-03-2013, 02:59 PM
I can see it now a Bearhawk LSA with an 0-320 in it to compete with a Carbon Cub

Lowrider
02-03-2013, 03:00 PM
912S would make sense weight wise in many LSA and maybe it is just me, but the Rotax makes a really irritating sound that pierces my David Clarks about 10 minutes into any flight. I'll take a C-90 or 0-200 any day!!

courierguy
02-03-2013, 05:38 PM
912S would make sense weight wise in many LSA and maybe it is just me, but the Rotax makes a really irritating sound that pierces my David Clarks about 10 minutes into any flight. I'll?

ake a C-90 or 0-200 any day!!
I haven't noticed that in 1200 hrs. of 912 time, with quite a few 8 to 12 hr days. Telex ANR headset, Sirius sat radio on all the time. Having said that, I really liked the way my A-65 sounded! I also liked being able to prop it. Of course, I had no choice....no electrical system.
Sound like a A-65 with 912s performance would be pretty sweet.

Lowrider
02-03-2013, 05:48 PM
Probably just me but the Rotax buzzzzz and Cont. hummmmmm. I'm sure it's just me.

courierguy
02-03-2013, 08:30 PM
Probably a prop problem, not the engine, they are smooth as silk. Some guys don't set their (grd adj pitch) props up right. Some lsa's have real light lexan windshields, must be doing some harmonic thing.

skywagon8a
02-04-2013, 07:08 AM
courierguy, I think that Lowrider is just referring to the noise that the Rotax makes as opposed to the Continental. I'm with Lowrider, I find that high rpm chainsaw noise objectionable also. That isn't saying that there is anything wrong with the engine.

Cub junkie
02-04-2013, 09:42 AM
The sound of the 912 is certainly not like a lyc or continental but I was impressed with the engine when I rode in a Zenith 701, one ugly airplane but impressive performance. I realize the 30's era technology while dependable is 30's technology and its time to move ahead. I just don't like the price of the Rotax engines. I can buy a serviceable small continental and all the raw materials to build an LSA like the Bearhawk or PA 11 replica for the price of the Rotax. Guess thats my stumbling block. The ship I rode in had some type of ground adjustable three blade that worked well but just doesn't look rugged enough to take off airport. The hub was a big chunk of CNC machining that looked out of place on an airplane. My fondness of the Bearhawk designs is in the wings, I like the all metal wings. The Patrol and the LSA have a Riblett airfoil too. I have a Champ anyway so an LSA isn't necessary in my stable except the Champ comes with the pain of certified airplane blues.

edit: I wonder what the military does with the high time Rotax drone engines, used market?

Bugs66
02-04-2013, 10:14 AM
How come all you guys building Cub Type LSA's experimentals are limiting yourself to the C90s and Rotax? What's wrong with 170-180hp? Cub Crafters figured out how to do it. Plenty of weight saving techniques for the Lycomings out there. My friend is rebuilding a C85 for his L-4 and the amount of money he is pouring into the overhaul he could have done the same with an O-320/360. Too much fuel? Pull the throttle back. Power there when you need it. Just a thought.

Cub junkie
02-04-2013, 10:34 AM
Good point Bugs but it takes discipline. I have a friend who went from an O-320 RV6 to a Harmon Rocket. He convinced his wife he would just fly around at 45% power most of the time and burn about the same amount of fuel. He never did do that, all that power is a drug and he used it. He doesn't have the Rocket or the wife anymore.

Bugs66
02-04-2013, 10:41 AM
Junkie, that's pretty funny! :-P Hope your friend found some other wings.

Cub junkie
02-04-2013, 10:46 AM
He didn't find any wings yet but he has another high maitenance wife! I'm going to talk with the Bearhawk designer today on some Patrol questions. I'm going to run the O-320 question by him and see what he says. I'm sure he will cringe as most designers do when people want to add more power right away.

Lowrider
02-04-2013, 10:55 AM
I was going to broach and 0-320/160 with Bob but had the same reservation. I'm thinking along that line if I go with his design and I believe as long as I stay a bit below the 140 VNE the plane shouldn't care one bit whats pulling it along. A little extra tube here and there should take up for the extra weight and all will be good...I think.

I had a high performance/high maintenance wife once and I'm here to tell you they ain't worth it...IMHO!!

Bugs66
02-04-2013, 11:08 AM
Yeah, O-320 with SkyDynamics flywheel, rear mount Alt (if want electric), Hartzel starter. What else is out there, lightweight sump? Throttle body lighter than carb? P-mag(s), Catto prop, lighter cowl, etc.

Super11XP
02-04-2013, 12:05 PM
Its hard to describe the way a 700-800 lb airplane flys, especially when the cg isn't at or a little beyone the forward limit. It's going to be really tough to get that light weight and cg not bumping the forward limit with an o-320.
As long as your going with an o-320, you might as well have flaps. Since you have the power to haul stuff, you might as well have an extended baggage. Since a 320 isn't as easy to hand prop as an 0-200, you might as well have a starter, and electrical system......
Say goodbye to your 800 lb airplane, it's starting to look more like 950-1050, which an 0-320 will have no trouble with, but it won't fly like the 7-800 lb plane.
I'm starting to sound like that cubdriver2 guy!!!

Bugs66
02-04-2013, 12:47 PM
Depends on your goals I guess. If you want a kite, build one. How about a Belite? But you can still have your cake and eat it too like a CC Carbon Cub. LSA but still has 180hp.

Lowrider
02-04-2013, 04:49 PM
Super,

CG is a good point and with full fuel I better loose some weight too!! A punched up 0-200 would probably be the right answer to get a little extra boost for take-off or maybe the Rotax but they sound awful and are expensive too. I'm not sure there is a practical way to run an 0-320 in an LSA and not cheat on the numbers.

Super11XP
02-04-2013, 05:16 PM
Depends on your goals I guess. If you want a kite, build one. How about a Belite? But you can still have your cake and eat it too like a CC Carbon Cub. LSA but still has 180hp.

Don't get me wrong, power is great. I demo'd a carbon cub last year at the lsa expo in Sebring. What a ride!!!!
I'm actually in the planning phase of building another cub and have an o-320 that I am planning to put in it, and would like to make it lsa.
Regarding putting a 320 in the bearhawk lsa, I think it would really be a performer, but I think it would be really hard to make it an lsa. Innovation is what homebuilding is all about. I'd say go for it, but it may get heavy!

Bearhawk Builder
02-04-2013, 07:02 PM
Of course I'm partial to Bob Barrows designs but I would recommend giving him a call with your questions and concerns, he's always been more than happy to discuss things with builders. He certainly likes to think outside the box and likes to hot rod things a bit so I'm sure he'll be happy to help with MO POWA. Ask him what he has in the proto LSA, I think it's a souped up O-200 that he says makes it climb like his patrol.

Lowrider
02-04-2013, 07:45 PM
Bob told me it was a C90-8 that he is flying now and he thinks that's about right for the LSA. I think he started with an A65 and he said it flew fine too. I guess it is all a matter of perspective. I guess the Carbon Cub flies at 80 hp which is <50% but what are the chances of folks really pulling the throttle back that far with an 0-360...I know...that is what the POH says.

Lowrider
02-04-2013, 08:00 PM
Anyone give any thoughts to wickerbills?

Dan D.
02-04-2013, 09:37 PM
Bob flew into our field a couple months ago with the LSA. Very nice, I sat in it and very roomy for me at 6' X 225 lbs. Looks like it climbs as good as the Patrol. We were going to see if the LSA would fly as slow as my little single seat Cub but I had a oil problem and stayed in the pattern and landed.
A friend of mine has a flying Bearhawk and he just bought the LSA plans and is cutting tubing. Going to use a lighten 0-200.
There are 3 Bearhawk projects in my hanger and another in a hanger across the runway. Maybe I'll get my BH finished someday.

Lowrider
02-04-2013, 11:22 PM
Dan,

That's too bad that you were not able to fly along side the LSA. What engine do you have in your Cub and what does it weigh? Single seat ought to be fairly light.

If you didn't have the Cub, would you follow Bob's design for an under 1320 gross plane?

Dan D.
02-05-2013, 01:08 PM
My little Cub is really a Super Koala narrowed down to 24" wide but built to the dimensions of the Koala 202. EW of 450 lbs. Not one part is the same as either one. Powered by a 1835 cc, 60 HP, VW engine. I am using a Helicopter airspeed and the stall speed is about 26-28 knots. Bob list the LSA stall speed at 30 mph.
If I didn't have so many projects, I would be building Bob's LSA.




Dan,

That's too bad that you were not able to fly along side the LSA. What engine do you have in your Cub and what does it weigh? Single seat ought to be fairly light.

If you didn't have the Cub, would you follow Bob's design for an under 1320 gross plane?

cubdriver2
02-05-2013, 02:38 PM
Its hard to describe the way a 700-800 lb airplane flys, especially when the cg isn't at or a little beyone the forward limit. It's going to be really tough to get that light weight and cg not bumping the forward limit with an o-320.
As long as your going with an o-320, you might as well have flaps. Since you have the power to haul stuff, you might as well have an extended baggage. Since a 320 isn't as easy to hand prop as an 0-200, you might as well have a starter, and electrical system......
Say goodbye to your 800 lb airplane, it's starting to look more like 950-1050, which an 0-320 will have no trouble with, but it won't fly like the 7-800 lb plane.
I'm starting to sound like that cubdriver2 guy!!!

:lol:


Glenn

Lowrider
02-05-2013, 08:36 PM
Dan,

Guess it would be hard to get a better endorsement than that. I've been looking around at other sites and Bearhawks seem to be well thought of pretty much everywhere but I gotta take a good close look at his LSA drawings before I make up my mind. I wish I had more time on the East Coast (can't believe I said that) and I would slip down to VA and get a close look at Bob's LSA but I'm leaving for the final trip to Idaho on the 8th....never to return until #3 son graduated from college.....maybe I'll come back for that.

Cub junkie
02-06-2013, 07:53 AM
Lowrider, the decision will be hard if you are trying to choose between the BH LSA or a cub replica. Both are great choices for an LSA homebuilt. If you choose the BH you are choosing a lightened up version of the Patrol. Lots of reasons to build a cub as well. If you tire of making cub parts you can buy high quality stuff from Javron and other builders of cub parts. I had a cub project up until '08 that I had to sell along with some motorcycles due to some big medical bills. When I started over I decided on the Patrol as my youngest son is not quite 14 and already 6'2". I will need a larger cabin than a standard cub can provide. He fills up the champ already. I'm already building your BH LSA in my pea brain, conical mount O-320 with catto prop. Titanium firewall and min electrics. Having built an RV you probably recognize the way the BH spars are designed. There is a neighbor of Bob's that I have talked with that has flown the LSA quite a bit and he loves it. Bob builds everything with what he considers a full electrical system....two magneto "P" leads. That is a full electrical system to Bob Barrows. When I talked with Bob yesterday I tippy toed around the O-320 idea on the LSA by asking how much horsepower can the airplane take. He responded that 100 hp moves it along as good as an O-360 moves the Patrol. I was too chicken to outright ask about the O-320 going on the LSA. Like you said as long as wt& balance meets requirements the airplane doesn't know what is pulling it along. Who turns down more power?

Lowrider
02-06-2013, 11:30 AM
Thanks Junkie!!

I just got hit with a big problem last night...my wife likes the bigger cabin in the BH LSA and going faster in cruise and it looks like I may be headed toward the BH for those 2 reasons. My wife is pretty understanding but something that I've learn in the 27 years we've been together is that when I have her support on something that she was not that wild about to begin with, I had better take advantage of it before she changes her mind. I already bought Carlson spars for the Cub so maybe I can use them in the BH config or sell them. I think I can build a Cubish LSA with a metal wing and make everyone happy.

The 0-320 is sure tempting and my first thought is lengthen the fuselage to keep the CG right but then that would further add to the weight problem...maybe Bob B. is correct...the 0-200 is the right answer....maybe set up for 115 hp or so....that should be enough I suppose.

Cub junkie
02-06-2013, 12:51 PM
They already have a BH LSA rib package available and considering the work involved I consider them a bargain. Carlson spars won't be hard to sell or trade. The back seat of the BH Patrol and LSA are very similar to a PA 12 so a pax won't feel the effects of wearing a chrom moly straight jacket. If you decide on the BH you can join me as one of the bastard children of SC dot org. Best flying board on the internet.

Lowrider
02-06-2013, 01:41 PM
Bastard children need love too!!

King Brown
02-06-2013, 03:59 PM
I remember talking to Richard when he rolled out the RV3. He cringed. What struck me particularly about him was that he hyped nothing; you knew you were getting the straight goods.

Lowrider
02-06-2013, 08:46 PM
You're right King...straight talk is hard to find these days.

That reminds me, I haven't asked this question before but I wonder if there is a BH LSA on floats? I guess that is another question I need to answer before I decide what to build. I'm set on having floats for whatever I build which makes the 0-320 even more at home on the nose. I suppose there might be some "beefing" to do on the fuselage to accomodate a float kit. This isn't going to be a "feather weight" plane any way I look at it. I suppose there is a price to be paid for everything in life.

DRLcub
02-07-2013, 10:25 AM
If you start beefing it up aren't you just building a Patrol? I'm interested in the Patrol for that reason. I have not seen ether one in real life and don't know all the differances. I wish I could find one or both in the Portland OR. area that I could look at and sit in (6'5" and 250lb).

DRL

King Brown
02-07-2013, 10:37 AM
We built our Bushmaster---stretched PA22 with Smith wings, 4130 steel, 15 per cent bigger tail feathers, as two-place. Just my opinion, and I consider the SC ideal, but a little extra weight is no real handicap getting into and out of tight lakes. Like the Cessna 185 (after the 180 and SCs), the weight and hp worked same way with the Bushmaster, it drops like lead after clearing the trees. 180hp with 84/43.

Cub junkie
02-07-2013, 10:44 AM
I'm sure the BH LSA will be sturdy enough for floats as is. I have atlee dodge style float fittings going on my Patrol. DRLcub, I think you will like the cockpit of the Patrol if you get to sit in one. Don't know of any in your area right now.

Bearhawk Builder
02-07-2013, 10:53 AM
There are no LSA's on floats right now, in fact I believe there are no other flying LSA's other than Bob's proto. The Patrol and the LSA, while they share similar designs are not the same, LSA is not a lightened up Patrol but a stand alone design. I talked with Bob some time ago about building a Patrol to LSA weight and he said it would be possible, like the Carbon Cub. That was before the LSA came out. Do you guys see this new medical rule going through at some point and wouldn't that do away with the need for LSA for most of us?

Cub junkie
02-07-2013, 11:10 AM
I gave up on keeping my Patrol light enough to meet LSA. I have built every welded part for it from scratch so I have a good idea on the weight of everything. I talked to Bob for a while on tuesday and he asked me what all I have changed from the plans so far and it's only one thing besides the aforementioned float fittings. I have added a folding front seat back copying the atlee dodge seatback for the PA18. Bob told me the Patrol proto weighed 970 with composite prop and no elec. system. Later it weighed 1027 on the revised W&B data he sent us builders. Keeping a homebuilt light is important but building it so you use it the way you want is more important. The hot rod cubs at Valdez are impressive but the only time those cubs are that light are when they are competing or practicing for the competition. Can you imagine going camping without your stuff so your airplane will be the king of STOL?

Lowrider
02-07-2013, 11:21 AM
DRL,

I'm not sure how much "beefier" the Patrol is than the LSA. I've read that that you can build the patrol light and still do an LSA gross, albeit with not much left for people and fuel. I goal is a light, adequately powered but not overpowered plane. My wife is interested in having the faster than Cub cruise and I still want to be able to do ops on sand/gravel bars and the like for hunting and fishing and just to be able to be there.

My C-170 will do some of that stuff, but not really that well and it looks like the LSA will cruise about the same 120 mph as the 170 with just 2 souls on board. I have the plans for a Cub clone and now the LSA so guess I'm leaning toward the metal wing and the faster cruise and I have a 5 day trip to ID starting tomorrow to think about it before I decide which way to go. There is some advantage in the Cub where I can buy lots of parts if I don't feel like making them. I don't think BH LSA is there yet so that may tip the scale too....so many things to consider...also the label of "bastard child" on the SC site could be a badge of honor!!

Lowrider
02-07-2013, 11:25 AM
Do you guys see this new medical rule going through at some point and wouldn't that do away with the need for LSA for most of us?

I'd love to have FAA get off their duff and approve that right now. Then I would build a one ton Cub with an 0-320/160 or so.

don d
02-07-2013, 12:00 PM
DRL,

I'm not sure how much "beefier" the Patrol is than the LSA. I've read that that you can build the patrol light and still do an LSA gross, albeit with not much left for people and fuel. I goal is a light, adequately powered but not overpowered plane. My wife is interested in having the faster than Cub cruise and I still want to be able to do ops on sand/gravel bars and the like for hunting and fishing and just to be able to be there.

My C-170 will do some of that stuff, but not really that well and it looks like the LSA will cruise about the same 120 mph as the 170 with just 2 souls on board. I have the plans for a Cub clone and now the LSA so guess I'm leaning toward the metal wing and the faster cruise and I have a 5 day trip to ID starting tomorrow to think about it before I decide which way to go. There is some advantage in the Cub where I can buy lots of parts if I don't feel like making them. I don't think BH LSA is there yet so that may tip the scale too....so many things to consider...also the label of "bastard child" on the SC site could be a badge of honor!!


Low rider

Come to payette. I'd. Check out my cub clone LSA. Mine has 0 235 /775 empty.

Don

Lowrider
02-07-2013, 12:18 PM
Thanks Don!! I'll try to do that very thing once we get settled.

Cub junkie
02-07-2013, 09:28 PM
Here ya' go Lowrider, check out the EAA experimenter magazine online with an article on the BH LSA. The pics alone are going to sway you. http://experimenter.epubxp.com/i/108002

Crash
02-08-2013, 01:37 AM
Unless a guy is in a real hurry to go the LSA route, I'd suggest waiting till the FAA rules on the EAA / AOPA's petition for exemption up to 180 hp and dropping the 900 lb EW / 1320 GW restrictions.

If this goes through it opens up a ton of new options for light aircraft users.

After attending Sun and Fun 2012, where there were LSA options at every turn, I came away not impressed with any of them for the flying I do (Alaska bush).

Just a thought.

Take care,

Crash

Lowrider
02-08-2013, 06:11 AM
Crash,

I'm with you. The BH will do my mission as a LSA but it they do approve the Rec Pilot change, I will still have the ability to go to 1500 lbs.

Signing off for a week or so while I move to ID.

Safe Flying!!

Crash
02-08-2013, 09:31 AM
Or I'd wait for this....

http://supercub.com/outlaw1.html

Crash

courierguy
02-08-2013, 10:29 AM
The carbon wing covering on this bird will be interesting. I saw the prototype while at the factory this summer, they had a wing rib/slat/flaps mockup showing how all the parts fit together. Manual slats, fowler typer super trick flaps, all carbon ribs. Projected stall and cruise numbers slower and faster then (by a lot) anything else out there or even talked about, if it wasn't coming from them I'd call BS, but we'll see. They told me the #'s but I won't repeat them as you wouldn't believe them.... lets just wait and see. Lots of really nice little details to make it easy to clean out, like a carbon tub floor you can hose out. Rear controls that quickly remove with no protruding hardware to hang up on gear.

Unlike other slatted birds, the design will do it's thing at a more normal AOA, not the extreme nose high one we've all seen. Thus the gear is nothing special:first off a Grove type spring gear because of its very low drag, (as compared to Cub style gear anyway) and to let the plane show off its high cruise potential. Cub type gear an option of course. Very large door/ or doors, like an S-7, due to the way the spars are laid out and the resulting structure, like 5' long.

Note they are using a Rotax 912S as the company owner feels it does the job just fine, in fact better then fine, and in fact has a whole lot of hours behind one (hunting coyotes out of a Rans S-7) it is one that has been "gone through" by a engine shop and is putting out 135 hp, still with the usual 2000 hr. TBO. Fuel burn should be 4+ GPH using premium mo gas. Too bad it will sound like a chainsaw and give the pilot a headache within 10 minutes. Sorry.... I just couldn't let those uninformed statements slide by! More like a BMW motorcycle and turbine smoothness plus the best power to weight ratio possible with proven reliabilty is why they are using it. Plus extensive personal experience in about as hard of flying as you can do, coyote hunting in Wyoming with the high DA's and down in the dirt, that is what this plane is all about.

qsmx440
02-08-2013, 11:27 AM
Looking at the picture of the BH one thing I noticed is the door. I really was taken by how practical the cub door is for hand propping. If you use the Rotax this is a non issue since you are stuck with electrics but with a Continental wouldn't the fold up/down door be a better option for an aircraft with no starter?

Cub junkie
02-08-2013, 12:07 PM
The BH door can be built seaplane style and clear the strut. So the hand prop style that many cub drivers use will work on the BH as well.

Lowrider
02-18-2013, 01:29 AM
Back up and running for the most part...2724 miles with a 10K lbs trailer behind my F250. Good trip except for ice in Eastern SD last week. Sandpoint is beautiful as always and the snow is melting...black bear in the yard last night.

I thought long and hard on the BH LSA and I think I'm going with it. Anyone talk to Bob yet about the 0-320? I'm not sure it is necessary and the extra weight may not justify the added performance but the extra power would be nice if you need it.

skywagon8a
02-18-2013, 06:08 AM
I thought long and hard on the BH LSA and I think I'm going with it. Anyone talk to Bob yet about the 0-320? I'm not sure it is necessary and the extra weight may not justify the added performance but the extra power would be nice if you need it.

What ever you choose just remember that your "new" sea level is 2100 feet and you will be flying in the mountains. Full throttle will already be 2" less manifold pressure.

SpainCub
02-18-2013, 06:31 AM
Any performance numbers on this yet? Can anyone please tell us more about he 613.5 airfoil wing? What is the cord on this wing? At what station is the single spar located? I bet is between the 15.75" or 18.90" mark if its a 63" cord. :D IŽd like to see a picture of the rib is possible :D

Bugs66
02-18-2013, 10:30 AM
Put flaps on it

Lowrider
02-18-2013, 11:20 AM
Sky,

Roger copy! I'm pretty familiar with high density altitude and hot which is another reason to look hard at the 0-320.

Spain,

Once I get my trailer and truck unloaded I'll try to get the figures from the drawings....at this point I'm not exactly sure where they are located. Perhaps someone will come up with a picture of formed ribs and specs and post it for us.

Bugs,

Flaps be good....I've been thinking about them...maybe Cessna style Fowler like things with a simple torque tube system in the roof. Can't add that much weight but i'm not there yet. I'm going to build the fuselage first so I have some time to look at flaps.

I asked about wickerbills or Gurney flaps on the wing but got no response to it....they would be easy and light. I asked Bob about using VG's and he said they are for poorly designed wings..'nuff said.

Cub junkie
02-18-2013, 11:33 AM
A simple torque tube thing is exactly how the Patrol flaps are accuated. Those flaps are 104" long.

Lowrider
02-19-2013, 01:10 AM
A simple torque tube thing is exactly how the Patrol flaps are accuated. Those flaps are 104" long.

Hmmm....may be looking for a drawing of the thing in a bit. I'd like to have an overhead flap lever too. Is that in the Patrol design as well?

Cub junkie
02-19-2013, 06:27 AM
No on the O'head flap handle. Its in the same spot as a stock PA18. After giving it some thought I think I would scrap the O-320 idea and go with a well built small continental. I think if you start adding a bigger engine you would need balanced tail which is heavier and then the flaps would also add weight. You are starting to venture into the area of the Patrol with those mods and losing the concept of building a sub 800 pound back country toy. I know you like the extra room the B'hawk designs have so have you considered a wide body cub fuselage with some light wings with flaps? The Patrol and the LSA both have a riblett airfoil but are slightly different from each other, along with the LSA having a narrower chord. The wings are one of the selling points of the Patrol for me. Lots to choose from for sure.

edit: I see someone has posted a pic of each wing drawing on Back country pilot in the Bearhawk Patrol LSA thread. That will get you started.

skywagon8a
02-19-2013, 09:20 AM
..... which is another reason to look hard at the 0-320.
0-320 vs 0-200??? This will be tough since there is 50-60 lbs difference between the two engines. There could be a serious CG problem unless the 0-320 can be moved aft a considerable amount? Removing a heavy starter and generator is possible for some of the shift. Perhaps mounting a wind driven generator on the tail would help some? Another thought would be to use an Aeromatic prop on the 0-200 in order to get the full power range available? This would total 221 lbs. An 0-320 with no generator, a light weight starter and a lightweight wood prop would be aprox. 230 or so lbs. Then mount a 10 lb or so wind driven generator on the vertical fin. The CG may be close to the same with each engine??

It is fun to think about various ideas. Perhaps some of my thoughts will help you trigger some ideas of your own?

Bearhawk Builder
02-19-2013, 06:01 PM
I talked with Mark Goldberg from Bearhawk Aircraft about the LSA and he has provided the following information -
From Mark Goldberg with Bearhawk Aircraft who makes the kits for the four place, the Patrol and the new LSA. Just a couple comments on previous postings. This little plane doesn't need flaps. It lands at 30 MPH and slips VERY well as do all Bob's designs. I would not think it a good idea to put in an O-320. Keep engines under 110-125 HP. If you want a bigger engine it would be wiser to go the LSA's big brother - the Patrol. The LSA airfoil was designed with lower power engines in mind. Happy to answer anyone's questions either on the forum or privately. N95MF@hotmail.com. Thanks. Mark
Dave

Bugs66
02-19-2013, 07:03 PM
It's too bad they didn't design in the flaps, they are nice to have. Gliders land slow too and have flaps or spoilers. The Rans S7, Highlander, and Sport Cub are LSA's and have flaps.

Tim
02-19-2013, 07:17 PM
It's too bad they didn't design in the flaps, they are nice to have. Gliders land slow too and have flaps or spoilers. The Rans S7, Highlander, and Sport Cub are LSA's and have flaps.

What Bugs said. I don't have them either, and it limits what you can do.

Lowrider
02-19-2013, 07:46 PM
I talked with Mark Goldberg from Bearhawk Aircraft about the LSA and he has provided the following information -
From Mark Goldberg with Bearhawk Aircraft who makes the kits for the four place, the Patrol and the new LSA. Just a couple comments on previous postings. This little plane doesn't need flaps. It lands at 30 MPH and slips VERY well as do all Bob's designs. I would not think it a good idea to put in an O-320. Keep engines under 110-125 HP. If you want a bigger engine it would be wiser to go the LSA's big brother - the Patrol. The LSA airfoil was designed with lower power engines in mind. Happy to answer anyone's questions either on the forum or privately. N95MF@hotmail.com. Thanks. Mark
Dave

Thanks Dave!!!

Mr. Goldberg,

Thanks for your offer!!

Do you folks have a web site with further info on the LSA parts available thru you with prices?

I've seen the published landing speed but have not seen a stall speed. Power on/off stall speeds are important info I believe. The flaps would be great things to have if you are trying to get a set of floats unstuck on smooth water or any variety of other short field "drop it in" landings. I think the 65 hp climb rate was something like 700-900FPM. What is the realistic rate for 0-200 at gross? I'm considering the 0-320 for the potential of getting good performance with floats and also a little extra umpf on take off....but the weight is an issue and I won't run a Rotax so there is no simple answer except maybe a hot rodded 0-200.

Any other insight into the LSA would be appreciated by many I think....based up the number of reads.

Thanks in advance!!

Super11XP
02-19-2013, 08:12 PM
Not trying to start a war here, just a question. How is it that a 65 hp tcraft or luscombe only get 4-500 fpm rate of climb (these specs I found on other sites) and the new bearhawk lsa is getting 700-900? Is the wing and airframe that much more efficent? Once again, I'm not trying to start a war, just a question...

Check Six
02-19-2013, 09:02 PM
Hi Clint,
Various reasons, really. In a nutshell, simplified, the Luscombe has a NACA 23012 airfoil and only 140 sq. ft. wing area vs. 170 sq. ft. for the Bearhawk LSA. The Tcraft has +/- 184 sq. ft. of wing and a NACA 4412 airfoil which has a lower Cl. (Both the 23012 & 4412 have lower design lift coefficients than the GA30A613.5 of LSA.) Prop, drag, Cm and other things factor in too.


Lowrider,
Have you considered the Corvair or an experimental O-290-D2?

Cheers,
Tom

Dave Roberts
02-19-2013, 09:14 PM
My guess is, He had a souped up 65 hp(closer to 75), now he has a souped up 85(closer to a 100 or better) not sure which engine the specs were derived from, also it is a cleaner fuselage and wing, so probably best rate of climb airspeed is faster than T-Craft or Luscombe. I think a high performance 85 hp T-Craft would stay with it.

Just a guess,
Dave

Lowrider
02-19-2013, 10:20 PM
Tom,

I did/have looked at the Corvair with the 5th bearing but the cost is right up there with the 0-200 and yes, the Corvair would be essentially a new engine but I think I want to stick with Cont/Lyc Technology. The 0290 weighs real close to an 0-320 and there are alot more of them out there, plus you can push the HP up on the 0-320 to better than 170 I believe without too much trouble and run pump gas....but I'm open to suggestions for sure!!

Check Six
02-20-2013, 01:07 PM
Hi Lowrider,

Yes, the initial cost of top of the line Corvair is up there with a used Lyc/Cont, but when it's time to rebuild/overhaul it becomes a lot more economical, however, you can't go wrong sticking with a Lycoming or Continental. O-290-D2s seem to be unwanted outcasts these days and there are some great deals on them to be found. They are a little lighter than an O-320. Parts are actually plentiful and many parts compatible with the -235 & -320. If experimental, the correct rings can be had from Hastings for about $50/hole. I converted my -290-D2 to 8.5mm (Accel) superconductor plug wires and auto plugs (NGK AB-6 & AB-7 plugs) - G3i has all the info for it along with a really nice electronic ignition that allows one to retain & revert to mags if the electronic ignition ever fails. Just tossing out options for consideration. Also, it's no big deal to open up the case to take Narrow Deck O-320 cylinders. Easy conversion.

Tom

Cub junkie
02-20-2013, 01:53 PM
Who is G3i ?

skywagon8a
02-20-2013, 03:19 PM
http://g3ignition.com/index.html

Cub junkie
02-20-2013, 05:44 PM
Thanks skywagon.

Mark Goldberg
02-20-2013, 05:58 PM
test reply

Lowrider
02-20-2013, 05:58 PM
Check 6,

I was on the verge of buying an old ground power unit 0-290 and doing just as you suggested with the G3i ignition and the one hole mag case and a IA talked me out of it. He said the cost would be right up there with a rebuild on a once run out 0-320 rebuild and getting more hp in the end with the 0-320 for sure. His logic is.... if you are going to convert something why not just start out with that engine to begin with and not worry about problems that may arise doing the conversion.

Back to the question...does the BH LSA need an 0-320 for short field work and floats? Does it need flaps and fold down double doors for the same reasons?

Doors: Yes
Flaps: Maybe
0-320: Dunno?

Thoughts?

Bugs,

Where do you buy CM in Spokane or better yet CDA?

Mark Goldberg
02-20-2013, 06:09 PM
While flaps are nice to have, on this plane with this airfoil, and with LSA weight limitations - the designer did not feel they were needed. He has not changed his mind after flying the LSA. Several very accomplished pilots have flown it, and every one has agreed that the slow approach and landing is already very good. As far as unsticking floats with flaps - just no knowledge on that.

Any of the small HP engines would be fine. I know Bob likes the Corvair engine more than any other auto engine in an airplane. But Bob believes the 4 cylinder Continentals are the best combination of power, reliability, and price. Bob will be building several variants of the 4 cylinder Continental for customers for reasonable prices. We will probably make an engine mount for the Rotax as well but not right away.

Just getting started on the Quick Build kits at our factory. One wing (first one) is being skinned now. First fuselage is finish welded and having all the other parts (tail surfaces, L/G, control stick assy etc.) made now along with the tooling to manufacture more kits.

Sorry there is not more info right now. Just the press release and spec sheet on our website. But we will be developing more info quite soon. Thanks. Mark

Check Six
02-20-2013, 08:50 PM
Thanks for the link Skywagon8a.


Lowrider,

The O-290-D2 is the only -290 engine I'd consider. In this day & age, I wouldn't ever consider a ground power unit even if it was free. Your I.A. is correct - converting a GPU O-290 would cost more and you'd still have a conversion with a crank with too thin a flange on it. However, I think an experimental O-290-D2 is certainly worth consideration, provided the cost of acquisition is right (keeping it certified would not be economically feasible with rings at over $120/ea x 3 per hole x 4 cylinders, etc., etc.). Even so, after reflection I think an O-290-D2 or O-320 would not be suitable for a Bearhawk LSA. It would be like the gent I observed years ago who went through the hassle and expense of sticking an O-320 on a Tcraft - ended up way past the point of diminishing returns and he wish he had never done it.


I have a set of LSA plans and have talked to Bob about the design of the LSA at some length. You can't turn a Bearhawk LSA into a Super Cub class plane. Think of the Bearhawk LSA as a new and improved J-3 designed for today's sized people. My 2 cents re: Doors, O-320 and floats - Doors: maybe; O-320: not worth the extra weight and increased fuel burn; Flaps: not worth the extra weight.

Tom

Lowrider
02-21-2013, 02:09 AM
Thanks Mark and Tom!!

I was at the monthly EAA meeting tonight and the BH LSA was discussed a fair amount and as expected the Carbon Cub owners said it needs an 0-320, an A&P and DAR said stick with the designer's recommendations and a lot of folks never heard of it and had no opinion. All the float pilots there (maybe 7) said yes to the door and flaps and maybe to the 0-320. 2 other Cub drivers (not SC) were impressed with the LSA specs but were not sure how accurate the numbers were on the web site...seemed a little optomistic to them.

What I came away with was I'm building the fuselage first and will most likely put in a fold down door and not the fold forward Bob included primarily for easier handpropping and float use. Jury is still out on the left door. The rest...we'll see, but the flaps sure seem like a good idea with lots of practical applications.

As in most discussions, everyone has an opinion and until we get more BH LSA's in the air, the discussion will revolve around opinion not based in experience or facts. Bottom line...I'm going to build one of some sort and find out for myself because I think it is a nice airplane and then I'll know for sure.

Bugs66
02-21-2013, 02:47 AM
Bugs,

Where do you buy CM in Spokane or better yet CDA?

I assume you mean 4130. Only place I know of is Alcobra Metals (www.alcobrametals.com (http://www.alcobrametals.com)) in Spokane. Walk-in or order online. Online prices usually better and you can do will-call. If going with a large order of tubing don't expect them to be as good price as ACS, although worth checking or asking. They are super handy for smaller quantity stuff or piece parts in a pinch. Also they have a remnant section that is great to browse.

Cub junkie
02-21-2013, 06:02 AM
Lowrider, as a Patrol builder I don't see how a fold down door would work and clear the strut on the BH LSA. A fold up one piece seaplane style door is possible as I have mocked one up on my ship.

Bearhawk Builder
02-21-2013, 06:37 AM
Remember too, as others have said that know way more than me about it, we really cannot compare the LSA to a Supercub, it's just not and not meant to be it's equal. It might be worth taking a good look at the Patrol which could easily be compared to the SC and has all the things you're looking for. The LSA is just that and from what I understand is an outstanding example on the type but I would fear that changing much with the design would push you over an edge you'd regret. I really would talk to Bob about your plans, he's very accessible.
Just my opinion.
Dave

Lowrider
02-21-2013, 09:25 AM
Thanks Bugs...yes, 4130, that's good info!!

Junkie,

I have not measured the door clearance so that is good to know. The one piece swing up door would be just fine for my use. Are you planning to use an aluminum frame and piston assist?

Dave,

I agree it is not a Super Cub and never can be. If FAA would approve the driver's license to fly Rec Pilot standards I would be building a Patrol not an LSA since that is what I really want. I was drawn to the BH LSA because if that goes thru, I can raise the gross to 1500 lbs and gain 180 lbs useful over the LSA with just paperwork and I believe it is a fundamentally good plane.

I believe it is the the collective LSA lobby to FAA that is preventing the approval of the initiative since there seems to be no practical reason to set the gross weight/speed limit on airplanes to be flown by us older folks where they are now....IMHO. Two souls in a 150 hp Super Cub is no more threat to life and limb than the same two folks in an LSA.

I've only owned 5 planes in my life and have always wanted a Cub (super or not) that would give good off field performance on wheels and at least average performance on floats and I believe the Patrol and BH LSA are better examples of the Cub than a cub itself (sorry cub guys), primarily because of the wing, cruise speed and interior size.

Something that was mentioned a lot last night during the 0-320 discussions was density altitude...summer flying from 8,000' fields is a lot different than Virginia and that is a big factor in looking at the 0-320 over the 0-200. Like other things in life, if you can't get it up, it ain't workin for you!!!

don d
02-21-2013, 12:00 PM
Try "Air Parts" for tubing and other materials.. Good prices and discounts that can almost cover shipping...

Cub junkie
02-21-2013, 03:09 PM
Lowrider, if you start with the fuselage maybe you can find someone in the EAA chapter that needs to order tubing. That way you can share truck freight and buy mill lengths, saves having a bunch of scraps from buying in UPSable 8ft lengths. You always end up with what I call wind chimes when you have to buy in 8ft lengths. There might also be some leads on tubing from an EAA chapter member, I've bought tubing that way when someone abandoned a project. On the question on my Patrol door, I have built a standard door set up except I used .028 wall tubing instead of .035. When I mocked up a seaplane door I built it out of scrap wood to see if it would work, then changed my mind and went with the standard door. I will have float fittings but not sure I will ever get the chance for floats. The float fittings will make the airplane more appealing at an estate sale.

Bugs66
02-21-2013, 06:48 PM
Hey Junkie, where's the pics of your project? Sounds like you have some real progress.

Crash
02-21-2013, 09:29 PM
If I were building LSA, my engine choice would be a Lycoming O-233. 40 lbs lighter then an O-235, cool new ignition etc..

https://www.google.com/url?sa=t&rct=j&q=lycoming%20o233&source=web&cd=5&ved=0CEcQtwIwBA&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DZzz ZMdpwJxs&ei=EdcmUZ-XG6_8iQLNhYDACg&usg=AFQjCNF-az-u-9oBw8KWVwg-vSFacR7iVQ&sig2=ggD5pzobf3Cprgtn6UXH5A&bvm=bv.42768644,d.cGE

Greg

Lowrider
02-21-2013, 10:45 PM
You're right Greg. The 0-233 is a fine engine and would fit the BH LSA just fine. When I lived in Homer in the late 80's I used to know a guy named Dan Draper in Nikiski and flew an old red Tcraft...still around?

7shannon
02-21-2013, 11:47 PM
Lowrider,
I have a set of Bearhawk Patrol plans, if you are in the neighborhood someday we could put them side by side and see what the differences are.
Bugs,
I met you last spring, your hangar mate was doing the pre-buy for the buyer of my Rocket, we were cutting open the oil filter in your hangar. I wound up buying a Wag Aero project instead of starting the Patrol because the price was so good and it happened to be a few miles from where I was working at the time. I cut the top deck off and built a PA-18 style cabin. Plannig on building wood ailerons and flaps when I build the wings. Still cant decide on O-320 or stroker C-85, dragging my feet on buying an engine hoping for the FAA ruling
Kevin in Deer Park

Lowrider
02-22-2013, 12:52 AM
Kevin,

Great idea!!

What are you doing Saturday? Shoot me a PM if you are available.

Bugs66
02-22-2013, 02:35 AM
Hey Kevin, sounds like a cool project. Go with the O-320 over C-85. More power is better, that is my motto. :-P

Did you sell the Rocket? Will check you out at Deer Park sometime soon.

Cub junkie
02-22-2013, 05:51 AM
Hey Junkie, where's the pics of your project? Sounds like you have some real progress.

I will have to take some new ones. Not used to anybody being interested.

Lowrider
02-22-2013, 10:39 AM
Hey!!....I'm interested!! I might be building a Patlsa so I'd love to see some details on the Patrol.

Cub junkie
02-22-2013, 12:08 PM
If you are going to build a hybrd we are going to have to come up with a better acronym. You could get your man card revoked talking like that.

Super11XP
02-22-2013, 12:16 PM
A guy I know put an 0-233 in his rans s-7. I could outclimb him just slightly in my c-90 cub and that was before I got my Catto prop. Personaly, I wouldn't want the 0-233. One thing you need to consider if you do put ANY lycoming engine in is that they are about 4 inches longer than a continental, so in addition to being heavier, the extra weight is sticking even further out there. If you could shorten the fuselage a few inches, I think the 0-320 would be pretty awesome in the BH lsa!

Dave Roberts
02-22-2013, 04:19 PM
One thing to think about if you are contemplating putting a 320 in the LSA. As a rule nobody builds one of Bob's designs as light as he does. Looking at the flying Bearhawks and Patrols out there, most are 100 to 300 lbs heavier than Bob's prototype specs. Add 100 lbs to the projected weight, then add an 0320 and end up with a 900 lb. airplane that was designed to be 750.

I'm not dissing the airplane. It's just that it is really easy to get a heavy airplane.

Dave

Lowrider
02-22-2013, 11:52 PM
Junkie,

I thought that was better than LSApat....

Clint,

I agree with the 0-320. I talked to a guy today that had a heavy 150 hp Cub on a high mountain strip last summer and had to wait until sundown to get it off the ground due to DA issues. I've aborted take offs more than once becasue the engine and prop just weren't doing what was needed to fly at a hot high field. I think we loose somewhere around 3%/thousand in engine power so the extra 0-320 power would help on wheels and floats on the LSA and the flaps can't hurt but they don't help on weight.

Looks like I may have a set of Carlson Cub spars for sale.

Dave,

You're right...light ain't easy and the bigger engine sure doesn't help. A skinny Patrol would give me flaps and bigger engine and make it a one person with 20 gals of gas and half a sandwich LSA at 1000 lbs empty. Could be done probably but also isn't the best answer. 900 lbs in an LSA would probably be fine without flaps and an 0-320.

Bugs66
02-23-2013, 04:46 AM
i know of a guy building a Cub here at Felts that might want your spars. Let me know if you sell them.

Lowrider
02-23-2013, 09:39 AM
Bugs,

Let him know they are available,,,still in the original wrappers. He can have them for what I paid...no shipping. And I have one Carlson Cub rib to use as a pattern.

Lowrider
02-24-2013, 10:51 PM
First I'd like to thank Kevin for putting up with me and my son while I looked thru the Patrol drawing. He is doing a bang up job on the remake of his Wag Aero Cub. His workmanship and innovations will make it a fun machine when he's done on wheels or floats!!

Next, the Patrol wing is different than the LSA but the fuselage, tail, gear and so on is pretty much the same as the LSA, just one size bigger in most of cases, i.e. 3/4 x 0.035 in the LSA to 3/4 x 0.049 in the Patrol. There are certainly other differences but none significant that I could find with a quick review of the Patrol drawings.

I think my first conclusion from todays exercise is that the LSA is every bit as fine a plane as the Patrol and that all the good comments I have read about the Patrol will also apply to the LSA....but perhaps in a different vain. I continue to believe the LSA needs flaps and with a little thought it could have them. The 0-320 question persists and the extra power it provides will certainly compensate for lack of flaps in some regard but not in all situations. Maybe adding the 0-320 will get me high density altitude advantage as well as better performance without the flaps....and still keep the plane in a reasonable empty weight for an LSA gross.

So, no decisions made today but I'm proceding with my fuselage build tomorrow.

Comments please!!

skywagon8a
02-25-2013, 05:40 AM
Since you still have the possibility of the 0-320 on the table, you should do some sample weight and balance with the two different engines before you start cutting tubing. Is there room to move the engine closer to the firewall? Should the wing be moved forward a little bit? Should the tail be moved aft a little? Make provisions to mount the battery further aft. Some helicopters have movable battery locations for CG shifts. IF you end up with your center of gravity too far forward you will regret all of those nice extra cubic inches. Planning now with minimize or eliminate the CG shift.

Cub junkie
02-25-2013, 06:17 AM
Lowrider, If you are starting on your fuselage right away I thought I would add a comment or two. I don't know how many scratch built fuselages you have built so If I'm preaching to the choir tell me to shut up. The Bearhawk line of fuselages are designed to be "space built" and not with a "side ladder" method that is common to scratch building a cub fuselage. The best way is to build your 18 ft jig table, build the top, remove it from jig and proceed to build the bottom. Then you build wood or steel fixtures to hold the top accurately over the bottom and fill in.1040010401

Lowrider
02-25-2013, 10:32 AM
Sky,

I am working the CG issue but at this point I'm not sure about weights of the engine, electric...yes/no, and so on. I'm building my table and ordering appropriate tube first and then will move to the tail then the bottom and top fuselage parts. At this point, I'm thinking 265 lbs is a good target weight for the 0-320 making it about 50 lbs heavier than the 0-200. It seems the weight delta is not a big CG factor but will reduce useful weight. At this point the easiest way looks like streaching the fuselage but I'm not there yet. If you have other ideas, please let me know.

If anyone has actual weights of a running 0-320 with and without alt/starter, etc., I could use the data please!

Junkie,

Don't stop with the info and pictures...it is good to learn/re-learn/refresh and pick up hints and lessons learned from anyone. I'm a sponge and will gladly take any info offered. I'm very interested in info from anyone building a Patrol!!

I'm thinking of a table like yours with electric and maybe air plumbed into the table so I only have one electic cord and hose to the table. Headed out this morning to get lumber. Keep the pictures coming...they are very helpful!!

skywagon8a
02-25-2013, 01:45 PM
Lowrider,
The weights and CGs for the engines can be found here: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/Frameset?OpenPage Just type in Lycoming or Continental then look at the particular engine of interest. You can easily calculate changes with the data which is provided. In fact, you can find the weights for airframe and propellers here as well under their appropriate TCs. Get some accessory locations from a visit to the airport.

Personally I prefer that the CG be more towards the aft than forward, since I have found that the overall performance is better in all respects. I am not suggesting operating outside of any tested limits.

Marty57
02-25-2013, 02:45 PM
Lowrider, If you are starting on your fuselage right away I thought I would add a comment or two. I don't know how many scratch built fuselages you have built so If I'm preaching to the choir tell me to shut up. The Bearhawk line of fuselages are designed to be "space built" and not with a "side ladder" method that is common to scratch building a cub fuselage. The best way is to build your 18 ft jig table, build the top, remove it from jig and proceed to build the bottom. Then you build wood or steel fixtures to hold the top accurately over the bottom and fill in.

My 2+2 fuselage went together the same way; top built first followed by the bottom. Jigging the two in alignment was relatively easy using wood bulkheads, plumb bobs and a smart level. Side tubes are then added and welded in place. Top deck with wing attach fittings is welded up and then jigged in place using same method. There are a lot more pictures on my site showing the process if you are interested.

Marty57



10410


10411

Lowrider
02-25-2013, 05:31 PM
Sky,

Thanks for the site...good info!!

Aft CG is best once you get her on the step and planed out. I never used to worry about aft CG until the South Central Beech 1900 pancaked in at HOM in I think '88 with a lot of deer meat in the rear locker. It flew just fine until it picked up some ice and during the flare the tail stopped flying...killed all on board. I flew on that plane in the same condition from Kodiak to Homer the day before loaded the same way....with no ice.

Marty,

Thanks for the pictures!! I picked up wood this morning for my table so I'm going to use some of your ideas on mine. I'll look at your site this evening. Thanks again!!

skywagon8a
02-25-2013, 05:41 PM
..... Beech 1900 pancaked in at HOM in I think '88 with a lot of deer meat in the rear locker. It flew just fine until it picked up some ice and during the flare the tail stopped flying...killed all on board.

Like I said, "within tested limits".

Lowrider
02-27-2013, 09:36 AM
I took a look at the Carbon Cub last night and it gets wonderful performance out of an "LSA" with a 180 hp that weights in under 900 lbs and I can't think of a good reason that the BH LSA can't be built to do the same thing with an 0-320 and flaps. It is difficult to determine the weight savings gained in using the carbon parts they call out on their site but it is probably significant. I have heard they use smaller and less tube in the fuselage than the Piper Cub but I don't have a way to verify this or find out what tube is actually used. If we have any CC owners/builders out there it would be great if you could share fuselage tube info with us. Also, anyone who has done any research on the CC structure, I'd be interested in that as well.

My table is half done and will finish it today. I ordered tail ribs from BH and they are 3 month out so I'm going to start with the layout of the fuselage bottom first.

C130jake
02-27-2013, 10:18 AM
CC fuselage has the top longeron on the top of the fuse. All the metal above the top longeron on a piper is gone saving weight without giving up strength. Some of the tubing on the tail feathers is smaller diameter on the factory CC vs the Top Cub/piper. 10452

Hope this helps,

Jake
building a CC EX

Cub junkie
02-27-2013, 01:29 PM
Sure a nice looking toy Jake. Keep us posted on your build.

Super11XP
02-27-2013, 02:38 PM
HI Jake, Do us all a favor and weigh you Carbon Cub fuselage. I'd like to know exactly how much lighter they made it.

Lowrider
02-27-2013, 08:21 PM
Thanks Jake!! A picture is worth a lot!! I'll second CLint's request for weight if you can get it and also how many ribs are there in the wings? I keep picking up tid bits on the CC with no way to confirm them and it is really great to find someone who has one under construction. That's gunna be a fine looking bird when you get done!!

Thanks again!!

Lowrider
02-27-2013, 09:50 PM
Oh, I forgot....bench is done and I ordered the tube for the LSA from API. They are cheaper than the local by a wide margin but they do have an 8' limit on tube. Layout of the fuselage bottom starts tomorrow.

7shannon
02-27-2013, 11:57 PM
Oh, I forgot....bench is done and I ordered the tube for the LSA from API. They are cheaper than the local by a wide margin but they do have an 8' limit on tube. Layout of the fuselage bottom starts tomorrow.

WOW their control cable is less than HALF what I just paid from ACS

C130jake
02-28-2013, 12:19 AM
Thirteen ribs...with extended fuel, the #3&5 rib are doubled an #2 is replaced with a bar along the bottom.

10455
The wing tips, floor, side panels, stringers and door are carbon. I will try to weigh the fuse by itself when I get a chance. Just looking at the Top Cub fuse side by side at the factory, it looked much heavier. Lots of extra bits welded here and there. CC says they reduced the fuse 200# by redesigning the frame and using carbon fiber stringers.


Jake

Lowrider
02-28-2013, 01:08 AM
Thanks Jake...again!!

Those are slick looking wing tips and I bet they are feather light too. I talked to a fellow who used to work at Boeing and he felt the vast majority of recent designs in the general aviation arena were over designed to compensate for potential law suits. It looks like maybe the folks in Yakama have overcome that hurdle. If the stringers saved 20 pounds or so, I wonder where the other 180 cames from? Are the fuel tanks carbon too?

C130jake
02-28-2013, 02:42 AM
The weight savings are everywhere. The fuselage part count was cut in half from the Top Cub/Piper design. Elec trim vs the old crank and cables saves a few pounds for example. The front seat support is molded into the carbon floor board. Anything that was wood in a cub is carbon. You are right, the wing tips weigh nothing. Fuel tanks are aluminum. Fuel lines and fittings are pex instead of aluminum. Every fitting on the wing is CNC milled to be as light as possible. Some guys are trying out 3lb LiFe batteries with up to 1100 cranking amps.

Once you add extended range tanks, extended baggage, lights, big wheels etc, some of the weight savings disappears.

Jake

Cub junkie
02-28-2013, 06:19 AM
Thanks for posting Jake. I definately have Carbon Cub envy. Cub Crafters left no stone unturned in developing this airplane. They spent a lot of money doing it. They owe me a hat from the defunct Super Cub pilots newsletter, I'm not sending them a big check till I get that hat. That last line is a joke by the way, that 25 bucks has been gone a long time.

Crash
02-28-2013, 11:56 AM
The problem often over looked with a bigger engine like an O-320 / O-340 in an LSA is fuel burn. To make the plane useful it has to have a decent range.

This is a problem the Carbon Cub had in it's original form. Great power and performance but no range with its small stock tanks. Cub Crafters then offered larger tanks ($3,500.00 option) but with the added weight, when filled, the plane then became (legally) a single person plane under the current LSA weight restrictions.

With the fuel burn of an O-200 or O-233 you can get by with smaller, lighter tanks which when full, still give you the ability to haul a passenger with a decent range.

I remember a few year back a guy built up a slatted wing, wide body Super Cub with an O-360 and 30.5 gallon Dodge tanks. The EW came in at around 1,350 lbs. Now think about it. The legal gross weigh of a Super cub is 1750 lbs. That leaves him 400 lbs of "useful load". Now fill the tanks (61 gallons @ 6 lbs per gallon = 366 lbs) and the "remaining" useful load is ONLY 34 lbs. He can't even get in the plane and fly legally, let alone haul a passenger and gear.

So just saying, LSA "empty weight" is only half the equation.

Take care,

Greg

skywagon8a
02-28-2013, 01:07 PM
The legal gross weigh of a Super cub is 1760 lbs.

I'm not picking on you. Just correcting the numbers, 1760 on floats and 1750 on wheels.

8GCBC
02-28-2013, 01:17 PM
Thread creep....

Under restricted category an 8GCBC can GW 2600#. That is fick'n heavy for 1400# empty. :-x

Crash
02-28-2013, 01:18 PM
I'm not picking on you. Just correcting the numbers, 1760 on floats and 1750 on wheels.

Thanks for the clarification.

He puts this plane on floats, although the 1,350 lbs was EW on wheels, but I changed my post to reflect a legal PA-18 GW on wheels.

Take care,

Greg

Lowrider
02-28-2013, 01:22 PM
Jake,

Thanks again!!

Greg,

Yip, I understand the extra fuel burn but if I can build the LSA under 900 lbs it will be a one person full fuel and 2 sandwiches plane that should get me a 3 hour, 400 mile plane (at 8 gph) and I can't hold it that long anyway. My wife hasn't been in a size 4 in years and I've outgrown my tool belt, but it will still make a good 1+ hour sight seeing plane with her on board and light fuel. 90% of my flying will be to off-airport strips, a lot of which are high elevation sites and in some cases short as well and I am having a hard time talking myself into the 0-200 when I can have 50+ hp for 50 extra pounds...I think.

Not that I would ever do it...I could pull the throttle back and burn less gas with the 0-320 too. Couple folks have asked, why not just go for an 0-360...hmmm.

I want to steal some CC ideas and try to make up the extra engine weight by simple and hopefully light things like the carbon seat and floor panels and maybe a cowl and wingtips if I can make it look right. I'm pretty good with fiberglass too so that's another option possibly.

Table is done and I'm laying out the top fuselage after breakfast and I'll take all the advise you folks have!!

C130jake
02-28-2013, 01:38 PM
The problem often over looked with a bigger engine like an O-320 / O-340 in an LSA is fuel burn. To make the plane useful it has to have a decent range.

This is a problem the Carbon Cub had in it's original form. Great power and performance but no range with its small stock tanks. Cub Crafters then offered larger tanks ($3,500.00 option) but with the added weight, when filled, the plane then became (legally) a single person plane under the current LSA weight restrictions.

With the fuel burn of an O-200 or O-233 you can get by with smaller, lighter tanks which when full, still give you the ability to haul a passenger with a decent range.

So just saying, LSA "empty weight" is only half the equation.

Take care,

Greg


Gregg,

I agree on the LSA weights getting eaten up with the options. (136lbs if you get them all and 29" tires)

I'm building to the 1800lb limit and should have a 900# plane when done. The CC340 engine helps quite a bit from an O320/360. 180hp for take off and is 40# lighter than a stock O320. The light speed electronic ignition is lighter vs magnetos for example and gives 5-6 gph at cruise and smooth running at any rpm. So even with the stock tanks, it will out fly my bladder.

Jake

Cub junkie
02-28-2013, 01:49 PM
Im sure there has never been a cub flown over gross weight, especially in Alaska.

Lowrider
02-28-2013, 02:38 PM
Im sure there has never been a cub flown over gross weight, especially in Alaska.

Perish the thought...that would violate the FAR's and everything your mother taught you!!!

8GCBC
02-28-2013, 02:43 PM
Last time I went against my mom she wrote me out of a big part of the trust! Never again!

irishfield
02-28-2013, 04:07 PM
Well the FAA has never trusted you.. so what's the worry! LOL

Lowrider
03-06-2013, 12:57 AM
Well, the first part of my tube order arrived from API and it is very nicely done. Made in FRG, lightly oiled, well packaged and arrived on time....well...2 out of 3 packages arrived on time. One bundle is AWOL but will probably arrive tomorrow. Also got refills on the A/O tanks and fired up the Smith Aviation torch which is functioning as designed and I'm ready to go in the morning with the fishmouthing (is that a word?) and tacking the LSA fuselage bottom. Still waiting for tail ribs and I just ordered a set of LSA wing ribs which I'm told delivery is 3 weeks out. Probably just another day for you veteran Cub creators but I'm excited!! If I knew how to post pictures I'd post a shot of the layout table and progress. Maybe one of my offspring can help.

Stay tuned...film at 11:00.....

Cub junkie
03-06-2013, 05:48 AM
Sounds like you've been busy. BH hydroformed wing ribs are a bargain and are very nice. On the tail ribs its nice to buy them if you can. They were not available when I built my tail feathers. By buying them preformed you eliminate all that dam carpenter work of building those individual form blocks. Who is API ? You say you are starting with the fuselage bottom ?

Lowrider
03-06-2013, 09:18 AM
Air Parts, Inc. (www.airpartsinc.com (http://www.airpartsinc.com)) They seem to have good prices and service...ordered tube Thursday and got it Tuesday...well 2 of 3 anyway which is the Brown Truck's fault I suspect. Yes, I'm on the bottom and if no one bothers me too much I will have it done quickly once the other package of tube comes. Goal is fuselage together by the end of the month...we'll see.

Cub junkie
03-06-2013, 10:26 AM
OK, never heard to them refered to as "API" I know them well since I'm from Kansas City and was a customer from the begining when Frank and Ethel started with their first bucket of surplus from wichita. I was spoiled then as I would go buy tubing in mill lengths so I didn't have to deal with wind chimes created by 8 ft max shipping length on the brown truck. Airparts has shipped me 12 ft lengths by airfreight and it wasn't bad on price. You going to build the bottom, then take it out of the jig, reconfigure and build the top, reconfigure the jig, put the bottom back in then put the top on? Please post pictures.

Dave Calkins
03-06-2013, 12:07 PM
Lowrider, please post pictures. It's easy after you've done it once! Your kids will know how to figure it out if you need help:)

It's basically a "click" to select the photos you have on your computer, with another "click" to "upload" the bunch to SuperCub.org

Glad to hear you are starting.

mvivion
03-06-2013, 01:56 PM
I took a look at the Carbon Cub last night and it gets wonderful performance out of an "LSA" with a 180 hp that weights in under 900 lbs and I can't think of a good reason that the BH LSA can't be built to do the same thing with an 0-320 and flaps.

Think again on the weights of the Carbon Cub. There's a thread on here right now where two owners of the CC in E/AB form state their airplanes weigh slightly over 1000 pounds. Even the factory carbon Cub is listed right at 900, without big tires, or any of a LOT of options that most folks are buying. To go there, folks are having to switch to E/LSA to make the plane legal, since E/LSA and E/AB don't require the maximum empty weight that S-LSA does.

And, note that the engine used in the Carbon Cub is NOT a stock lycoming engine, by any means, so you'd need to plan electronic ignition, small oil sump, etc, etc. to get close to that weight. I seriously doubt anyone could build a Carbon Cub with electrics at less than 900 pounds, and most are going to be more like 1000 I'd bet.

MTV

8GCBC
03-06-2013, 02:00 PM
I would simply break the law every day IF flying LSA, so I choose a regular aircraft(s). I wanted the ticket, but wife saw W/B, and put project on indefinite hold.

sierra bravo
03-06-2013, 02:30 PM
I seriously doubt anyone could build a Carbon Cub with electrics at less than 900 pounds, and most are going to be more like 1000 I'd bet.

I don't think that's correct. A couple of guys I know with Carbon Cubs that weigh 1000# have long range tanks and 31" Bushwheels. Those two items add about 100#. They also have some other nice additions that could be left out. A 900# Carbon Cub is definitely realistic. A careful builder could do a well appointed Carbon Cub on 29" Airstreaks at under 900#, at least that's what my research is indicating.

Lowrider, have you asked CC if they'll sell you their CC340 engine?

spinner2
03-06-2013, 09:09 PM
The problem often over looked with a bigger engine like an O-320 / O-340 in an LSA is fuel burn. To make the plane useful it has to have a decent range.

This is a problem the Carbon Cub had in it's original form. Great power and performance but no range with its small stock tanks. Cub Crafters then offered larger tanks ($3,500.00 option) but with the added weight, when filled, the plane then became (legally) a single person plane under the current ...

Take care,

Greg

The CC O340 is a very efficient engine. I plan for 5-6 gph with mine and at sub 2000 rpm it'll be closer to 4. Even with the standard 26 gallon tanks that's a pretty good range. I have the 44 gallon tanks and have gone over 7 hours several times and topped off putting in +/- 35 gallons. The big tanks add about 25 pounds to the empty weight.

Lowrider
03-06-2013, 09:27 PM
My other tube showed up today thanks to Brown so I'm ready to build a fuselage.

I spent an hour or so with an IA who used to build engines for race planes years ago. He says I should put the 0-320 with some improvement work in the LSA...no sweat...getting 180 hp out of an 0-340. He described spending hours on the mill and lathe taking weight off the race engines but it's not necessary on a normal plane. The 0-340 is just an 0-320 with a new crank and bigger jugs and who doesn't like bigger jugs.

He seemed to think a less than 900lb LSA with 0-320/0-340 and flaps was entirely possible and would be a fine airplane. He thought a well built 0-320 at reduced power would equal or better an 0-200 on fuel burn and produce the same cruise and still be able to do 2000 fpm climbs when desired.

Regarding flaps...no reason not to have flaps, just use a proven design for the flaps and controls and the DAR should be just fine with adding them to the BH LSA.

All in all, a very positive and fruitful discussion.

Pictures...oh yeah...pictures....it's snowing hard and maybe in the morning I'll take some and try to post them.

spinner2
03-06-2013, 09:30 PM
Think again on the weights of the Carbon Cub. There's a thread on here right now where two owners of the CC in E/AB form state their airplanes weigh slightly over 1000 pounds. Even the factory carbon Cub is listed right at 900, without big tires, or any of a LOT of options that most folks are buying. To go there, folks are having to switch to E/LSA to make the plane legal, since E/LSA and E/AB don't require the maximum empty weight that S-LSA does.

MTV

Mike and I had this conversation a couple of nights ago at the MT Aviation Conference. It would be easier to get close to 900 pounds with a factory built LSA than an EAB like mine - the EX kit. The kit plane adds about 25 pounds with a few extra fuselage tubes, Univair PA18 tail feathers, 3" gear as standard, medium weight fabric as opposed to LW fabric on the CC-built planes and probably a few other things I'm forgetting. The reason for this is that CC doesn't know if the builder is going to register the plane as a 1340 gross or as an 1865 pound gross like mine.

Mine also has some heavier extras like 31's, Baby Bushwheel, heavier but more effective brakes I traded with Grove for the LW set that came with the kit, a large extended baggage (not the CC option), Dodge long step, 44 gallon tanks, Pawnee tail spring and no doubt something else or two I'm overlooking.

My empty weight is about 995. It would be fairly easy to chop 50 pounds off of that with different gear and tire choices and standard tanks. Going with the automatic 25 pound reduction with a non-kit plane would help more. But I think getting under 900 and having tires of any size would be hard.

That said though, a 1000 pound 180 hp Cub is a great performer.

Lowrider
03-06-2013, 10:48 PM
Spinner,

We talked abut the CC today too and the "missing" fuselage tubes. No one seems to know exactly what they left out or why it was OK for an LSA to not have them other than possibly extra gross weight. The fellow showed me some fiberglass covered honeycomb material that could be made using carbon fiber and would result in weight savings and additional strength for something like floor decking or other structural application to reduce weigh.

Anyway, I know the CC is a redesigned Cub but where are those missing fuselage tubes...are the tubes just spaced out to save a few????

spinner2
03-07-2013, 09:48 AM
Spinner,

We talked abut the CC today too and the "missing" fuselage tubes. No one seems to know exactly what they left out or why it was OK for an LSA to not have them other than possibly extra gross weight. ??

Keep in mind that the CC fuselage is not the same as a PA18 fuselage. The big difference is that the turtle deck is eliminated making the top longeron the top line of the fuselage. This makes for a stonger framework and eliminates sometimes-flimsy turtledeck.

The 'extra' tubes that come welded into the EX fuselage are on the bottom side under the baggage/rear seat area. I don't think there are any other changes as far as tubes go.

Lowrider
03-07-2013, 10:44 PM
105561055710558

Thanks to the help of #2 son the above pictures were taken just before we took the bottom of the fuselage out of the jig. We have the top of the fuselage laid out and will begin work in the AM. Some of my tacks got a little more like finished welds, but then I hope nothing needs to be tweeked anyway. We should be able to get most of the top done tomorrow and start the bends and jigging of the upper and lower fuselage parts on Saturday.

Spinner,

Thanks for the info on the "missing tubes". That makes perfect sense to loose the stringers and seems like a good solution for mine as well which would help with weight too.

irishfield
03-07-2013, 10:55 PM
Lookin good there LR... but do yourself.. or your son a favour. Just because Orange County Choppers welds in bare hands and T shirts for TV doesn't mean it's right. Get some sleeves on.. and gloves. Skin cancer will come fast enough without the arc tan!

Lowrider
03-08-2013, 02:37 AM
Good catch Irish!! We do wear jackets and gloves when welding...well mostly...the picture on the left is a set-up photo op for these pictures. I told him...weld something and I'll take your picture. I also learned a long time ago to wear black when welding...white sure reflects that flash back under the helmet.

Update...couldn't wait until morning so we almost finished the top tonight...4 pieces to go in the morning....then jigging....things really go fast with two people working. It is surprising how much faster the top fuselage went compared to the bottom. Not near as much head scratching and looking at the drawings with a dumb look on our face.

Bugs66
03-08-2013, 11:45 AM
Looks like the date on your camera is off ;) Nice work

Lowrider
03-08-2013, 12:09 PM
Looks like the date on your camera is off ;) Nice work

Actually Bugs, it is set for international or military time...7 Mar 13...07/03/13 if you perfer. It is still on East Coast time though...must correct.

Update...top is done and awaiting #2 son to wake up to help with bending and jigging.

Lowrider
03-08-2013, 10:54 PM
10592

Bottom is bent and secured and the at the moment not so stable uprights are holding the fuselage top which will have to wait until morning to get any action from the plumb bob and level. The bottom took a little tweaking to get it lined up properly and secured to the table after bending. The nearness of the camera makes it look like the top is significantly higher than it should be but it is the required 13" center to center on the tail post. So far, things are very straight forward and relatively easy to accomplish.

Lowrider
03-10-2013, 01:04 AM
106131061410615

Another productive day....top and bottom are secured, square, plumbed and level and both sides from the tail to station C are fitted and tacked in place +/- 1/8" and straight on an 8' straight edge to <1/4" in 8 feet. I know...not perfect but I'm usually an aluminum kind of guy.

Now comes some thought on the tail wheel and the seaplane door on the right and a variety of other little things to consider.

Has anyone built an A frame tail wheel with a coil over shock for suspension? I think I have seen pictures of such a thing but can't remember where. Seems it would be lighter and provide better off runway shock absorsion than a conventional tail wheel....thoughts?

Lowrider
03-10-2013, 01:11 AM
Oh yeah...Spring forward!!!

Check Six
03-10-2013, 09:02 AM
Nestor used one in his Slepcev Storch design. I've seen them on some other aircraft but can't remember where, either. A coil over with an adjustable rebound would be worth pondering....

skywagon8a
03-10-2013, 09:25 AM
Has anyone built an A frame tail wheel with a coil over shock for suspension?
Here are some samples:

http://ts2.mm.bing.net/th?id=H.4558945517765045&pid=15.1 http://ts2.mm.bing.net/th?id=H.4851097759581481&pid=15.1

Stinson Model T
http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Stinson_Trimotor.jpg/800px-Stinson_Trimotor.jpg

Travel Air S-6000-B
http://www.deltamuseum.org/Images/deltahistory/livery/01_Travel_Air.jpg

Lowrider
03-10-2013, 01:44 PM
Thanks fellows!! The Stinson is just about what I was thinking only using an light ATV or mountain bike coil over that would come close to the weight I expect on the LSA tail.

Got the left side of the fuselage done this morning except the firewall. I'm only putting the seaplane door on the right side since a lot of folks say they seldom use their left door and it would add weight. The door will lift up agains the wing and will have a window that will open when the door is closed. Left window stays too.

My wife has me talked into a casino and dinner later so maybe I'll take a break this PM...

spinner2
03-10-2013, 06:00 PM
The Travel Air 6000 is one of the neatest planes ever. I rode in Hank Galpin's a few year is ago. And there's an excellent book by Jim Reardon about another one with an amazing history.

But the point of this is to ask Lowrider if he is doing this work in Sandpoint Idaho? I'm up the river about 100 miles.

Lowrider
03-10-2013, 09:53 PM
Yes Sir....'bout 12 miles North. Is Thompson Falls a good guess?

skywagon8a
03-11-2013, 05:02 AM
Has anyone built an A frame tail wheel with a coil over shock for suspension? I think I have seen pictures of such a thing but can't remember where. Seems it would be lighter and provide better off runway shock absorsion than a conventional tail wheel....thoughts?

Another "A" frame tail wheel airplane is the Grumman Widgeon. The weak point on this gear is the point at which the "A" frame is attached to the fuselage. It can fail with a side load in rough ground or when pushing it backwards over the hangar door lip. So, you need to be sure that the "A" frame attachment to the fuselage is very strong along with the surrounding structure.

Mark Goldberg
03-11-2013, 08:40 AM
Over the weekend, Bob Barrows flew his Bearhawk LSA to visit a friend with a 180 HP Super Cub. The Super Cub has a 84" Cato with 44 pitch. They did a competition. The BH LSA (Bob solo) took off shorter and out climbed the Super Cub with two people in it. Their cruise speed was just about the same. Mark

Lowrider
03-11-2013, 02:38 PM
Mark,

Interesting but not exacting apples to apples....just think what he could have done with flaps and an 0-320!!

Did you ever come up with a power on and off stall speed?

I just looked up Zenith amphibs this morning and they weigh 100 lbs plus the rigging and hydraulic pump/tank. That's probably right at the 1000 lb point if I can build as light as Bob and add in the extra drag. That's becoming quite a load on an 0-200.

I have most of my basic fuselage tube done and am ordering the material for the gear tomorrow so I can use the tail ribs as soon as they arrive.

Thanks,


Joe

skywagon8a
03-11-2013, 03:27 PM
That 100 pounds is only for one float.

Dave Calkins
03-11-2013, 05:06 PM
Over the weekend, Bob Barrows flew his Bearhawk LSA to visit a friend with a 180 HP Super Cub. The Super Cub has a 84" Cato with 44 pitch. They did a competition. The BH LSA (Bob solo) took off shorter and out climbed the Super Cub with two people in it. Their cruise speed was just about the same. Mark

What were the particulars about the "contest"?

Wind? Takeoff roll length for each? Temperature? ...stuff like that???

Steve's Aircraft (Steve)
03-11-2013, 05:43 PM
Has anyone built an A frame tail wheel with a coil over shock for suspension? I think I have seen pictures of such a thing but can't remember where. Seems it would be lighter and provide better off runway shock absorsion than a conventional tail wheel....thoughts?

The new Just Highlander Super STOL has that... Saw a pic of it posted I think on on BCP...

Brian

Lowrider
03-11-2013, 08:42 PM
The new Just Highlander Super STOL has that... Saw a pic of it posted I think on on BCP...

Brian

Thanks Brian!! I'd love to see the specs on the coil over. I looked last night for an acceptable progressive coil rating to start at around 100 lbs and max out at maybe 300lbs with an adjustable flow shock. All I could find was a cheap Chinese go kart shock or a $500 custom job. I'll look on BCP.

Mark Goldberg
03-11-2013, 08:46 PM
The side by side flying Bob did with a friend in his SuperCub was not anything too formal. And the test was for sure not apples to apples since the SuperCub had two people. Just posted it for what it was.

As to how Bob's plane would have done with an O-320 & flaps - that is something you will find out when you finish and fly yours. These are not approved by Bob on his Bearhawk LSA design, and you will be the test pilot for the bigger engine and the flap system you design and install your homebuilt. You have every right to do what you want of course. But I am not as sure as you seem to be that an O-320 and flaps will be beneficial. I am not an engineer, and rely on one for his design expertise and recommendations. But I wish you the best of success with your project.

Bob will be visiting me soon, and if the weather is good I will fly his LSA and post my impressions. Mark

spinner2
03-11-2013, 08:47 PM
Yes Sir....'bout 12 miles North. Is Thompson Falls a good guess?

A little farther up the canyon at Plains, S34. Six miles from Paradise :)

Lowrider
03-11-2013, 11:24 PM
Mark,

Isn't that what experimental is all about?

I'm not sure about anything except that I think Bob's design is sound or I would be building a Cub clone....we'll see how it turns out.

Spinner,

Know right where it is. I hit a traffic jam in Paradise once...I think it involved a horse....and a bunch of folks trying to catch it. If you get over this way, stop in.

Lowrider
03-11-2013, 11:47 PM
Lowrider, as a Patrol builder I don't see how a fold down door would work and clear the strut on the BH LSA. A fold up one piece seaplane style door is possible as I have mocked one up on my ship.

Hi Junkie,

I've been discussing the right seaplane door with several folks and the IA that is keeping me from doing anything stupid and I mentioned that you had mocked up one for your Patrol and he suggested I get some input from you on what you learned....sizes, materials, hardware and so on. Any light you can shed or lessons learned will be appreciated!!

Cub junkie
03-12-2013, 12:49 AM
All I did was rip some pine lumber into 5/8" square strips and build a temporary framework in the door opening. I used a couple of cabinet hinges at the top clamped in place and some more lumber to simulate the strut and wing spars so I could check the swing and see if it would clear the strut and I determined it would. I was going with it but then decided to use the stock set up instead. The material I used for the doors and windows is what is called out on the plans.

Lowrider
03-15-2013, 04:08 PM
All I did was rip some pine lumber into 5/8" square strips and build a temporary framework in the door opening. I used a couple of cabinet hinges at the top clamped in place and some more lumber to simulate the strut and wing spars so I could check the swing and see if it would clear the strut and I determined it would. I was going with it but then decided to use the stock set up instead. The material I used for the doors and windows is what is called out on the plans.

Thanks Junkie!!

I've been dealing with defective modem and a lack of speedy service froM Hughes Net. All fixed now.

I have finished all the tubing on the fuselage except the tail wheel and I'm starting on rudder pedals and controls along with the tabs to mount the floor. Plans call for .032 al for areas where where you step and .020 for other areas. Seems pretty light and creaky but the book says it will hold up OK. May add some .063 under the pilot and pax foot area.

brown bear
03-15-2013, 04:50 PM
"May add some .063 under the pilot and pax foot area"
I read as ,may add some weight:lol:

Lowrider
03-16-2013, 12:00 AM
"May add some .063 under the pilot and pax foot area"
I read as ,may add some weight:lol:

Point made...but...that was a compromise instead of .080. I suppose I'll try the light stuff and see if that will keep my feet out of the prop wash.

brown bear
03-16-2013, 07:31 AM
If you want to build as lite as "Bob" you got to think like Bob. If you are thinking about adding something to your plane thats not in the plans, Then hold it up in the air head high and drop it. If it hits the hangar floor its to heavy. ":lol: Doug

spinner2
03-16-2013, 08:00 AM
Point made...but...that was a compromise instead of .080. I suppose I'll try the light stuff and see if that will keep my feet out of the prop wash.

With the layout of fuselage tubes in a PA18, .050" aluminum on the floor is very adequate.

Gordon Misch
03-16-2013, 09:28 AM
With the layout of fuselage tubes in a PA18, .050" aluminum on the floor is very adequate.
I used .040 on the cockpit floor of my 12, with some .040 channel stiffeners riveted onto the bottom side in the spots that would bear weight. Works fine.

Lowrider
03-16-2013, 09:28 PM
If you want to build as lite as "Bob" you got to think like Bob. If you are thinking about adding something to your plane thats not in the plans, Then hold it up in the air head high and drop it. If it hits the hangar floor its to heavy. ":lol: Doug

Good logic Doug!!

I'm going to go with Geezer's idea of the extra stiffeners made from .064 on the .032 and see how that works out. I'm still a little "iffy" on the .020, besides I have some .025 on hand so I think that will have to do. I going to tell my wife she must sit on the floor to make up for the extra weight and she only gets one seat belt too....we'll see how that works.

Dave Calkins
03-17-2013, 12:14 AM
....the plate they will install in your skull after she belts you will take up the extra weight of her seat. Careful!!

Glad to see you moving along Lowrider!!

brown bear
03-17-2013, 09:45 AM
Once again, try to think lite . Ask the Doc to use a Titanium plate. Doug

Lowrider
03-17-2013, 12:00 PM
So...you guys know my wife...more likely is she'd knee cap me with a pellet gun just enough to hurt but no real damage done.

Built the front seat and seat rails this morning and I'll probably get the seat frame and rails welded after nap.

I think I'm going conventional with the tail wheel. The spring/shock/A frame/yoke idea still seems good but after adding up the parts the weight killed it....thinking light Doug!!

Dave Calkins
03-17-2013, 01:02 PM
I didn't want to kill your creativity by suggesting to stay with a conventional tailwheel for the parts-count and weight savings alone.

I like the idea of a "real" dampened tailwheel suspension, so I was waiting to see if you'd do it.

skywagon8a
03-17-2013, 02:33 PM
I think I'm going conventional with the tail wheel. The spring/shock/A frame/yoke idea still seems good but after adding up the parts the weight killed it....thinking light Doug!!

If you are still thinking about the 0-320, that little bit of extra weight at the tail wheel will help with the CG. Proper CG location deserves as much attention as the weight.

Lowrider
03-17-2013, 07:14 PM
10737

I'm following you guy's advise and have provided my wife with a seat and you may note that the cushion can be used as a flotation device in the unlikely event of a water landing.

Sky,

I'm actively looking for a deal on a 1x run out 0-320 so it is still in the mix. I'm mindful of the CG issues and hope to have a better feel for the nose weight issue once I get the gear, tail and wings in place and can better establish approximate CG.

Dave,

I'm still in favor of the dampened tail wheel but it adds weight, complexity and fits into my usual tendency to overbuild things which further compounds the weight issue. #3 son who is here visiting for Spring break came up with the idea that once I figure out how to build the LSA, I should build another for him and his brothers to fly so we might try it on that one...'cept he hasn't figured out how they are going to pay for it yet as an under employed college student, an unemployed butcher and a federal cop.

Check Six
03-17-2013, 09:11 PM
Lowrider,

There's a Stinson L-5 in the hangar next to mine that has the type of tailwheel you're talking about. Adds complexity and weight. I suggest going with a titanium tube spring and a Bob wheel from Scott Iron Design http://www.irondesign-airparts.com/Tailwheels.htm

Tom
Keep it light

Dave Roberts
03-17-2013, 10:26 PM
Lowrider, I have .032 2024 in all the floor area on my Bearhawk. It holds up fine. If I'm hauling something in the baggage area that may dent it, I just throw in a piece of 1/4'' plywood. No use hauling around extra weight when you don't need it. Keep it light.

Dave

brown bear
03-18-2013, 05:41 PM
I have been useing a titanium tail spring for some years .Its great and the fatigue life is said to be many many times spring steel.
Doug

Lowrider
03-18-2013, 06:47 PM
Dave,

I'm pretty well settled on .032 and .025 on the baggage area. I think I will put some stiffeners in some areas of the .032 just in case. Easier to do it now than later.

CK6,

Bob wheel is on the short list with the TI spring....still looking at some other options.

I finished the front seat for the most part yesterday and started on the rudder pedals. For some reason yet unknown I made them canted in so my boot would lay flat on the pedal and the process turned into a series of compound angles which made the whole process more complicated than necessary. Guess I will stick with the method with the left pedal but it sure was time consuming...that'll teach me to do custom things.

Lowrider
03-19-2013, 10:15 PM
Finished up the left rudder pedal and am waiting for the brake cylinders to arrive so I can finish them.

I had the drawings for the rudder and horz stab blown up to life size and that should make it a lot easier to construct them on the table. Still waiting for the ribs from Avipro but I may lay out the rough shape and not weld anything until I get the ribs.

ANyone use Grove brakes or wheels? They cost a fair amount less than Cleveland.

Dave Roberts
03-20-2013, 09:31 PM
I have Groves on my Bearhawk. They have held up well. No complaints.

Dave

Lowrider
03-20-2013, 11:34 PM
Dave,

Did you use the 1 1/2" weld on axle with the Grove brakes and wheels?Any problems installing the brakes?

Dave Roberts
03-20-2013, 11:41 PM
Yes, mine have the 1 1\2'' axle. No problems with the brakes at all.

Dave

Lowrider
03-21-2013, 01:30 AM
Dave,

I'm sorry, I didn't word the question properly. The Grove axle is a bolt-on axle (ACS part # 06-00919) rather than the weld-on axle suggested in the plans and it looks like the Grove bolt-on appears to be machined differantly in the pictures on the ACS site where as the weld-on axle is just a 1 1/2"x 16 TPI hollow tube that welds into the main gear.

Don't mean to complicate this but I just don't want to order the wrong axle to go with the Grove brakes/wheels.

Thanks!

Dave Roberts
03-21-2013, 08:56 AM
Mine is the weld on axle as per plans.

Dave

irishfield
03-21-2013, 09:04 AM
Just talk to Grove directly.. pay less.. and get exactly what you want. They make stuff that's not in that catalog as well...

http://www.groveaircraft.com/index.html

Lowrider
03-21-2013, 12:18 PM
Thanks Dave and Irish!!

I'll give them a call.

Lowrider
03-21-2013, 11:40 PM
Rear seat is completed this morning and I built it with pockets for the seat to sit in so I can pull 4 clevis pins and the seat pulls right out of the plane. Seat belt brackets are attached to the longerons and not the seat and it will have shoulder straps that attach to the overhead for a 4 point set up like the front seat on a retractor.

I'm putting brakes only on the front pedals. Any thoughts on brake lines? My thought is steel and stainless shielded hose inside and out to the gear and steel to the calipers down the the gear leg.

spinner2
03-22-2013, 05:54 PM
I'm putting brakes only on the front pedals. Any thoughts on brake lines? My thought is steel and stainless shielded hose inside and out to the gear and steel to the calipers down the the gear leg. I used a high pressure poly-type tube that came with my kit. Nice and light and easy to position. Do you have the masters in the front? I used stainless steel braided hose from the fuselage to the wheel. This line did not come with the kit. Bulkhead fittings where the lines penetrate the fuselage. I also have no brake pedals or rudder pedals in the back. No stick or throttle either.

irishfield
03-22-2013, 06:15 PM
18 years now.. on Parker Parflex NR-4-035 and it has never let me down whether it be wheel gear or amphibs. 425psi working - 1700 psi min burst. If you're real worried go up to the -050 @ 625psi working / 2500 min bust.

Lowrider
03-22-2013, 10:18 PM
18 years now.. on Parker Parflex NR-4-035 and it has never let me down whether it be wheel gear or amphibs. 425psi working - 1700 psi min burst. If you're real worried go up to the -050 @ 625psi working / 2500 min bust.

I'm a long time user of Parker hoses for a variety of differant applications as well. I've only tried their tubing on dirt bike brakes but that sure makes sense. Never had any problems with them and it is bound to be less expensive than shielded hose. At first I was a little concerned using their light weight aluminum fittings but they held up fine...even after a few crashes. That may be what Spinner is using too without knowing it.

I'm glad you mentioned that Irish!! I had forgoten about them but will look into it for sure.

Lowrider
03-22-2013, 10:25 PM
I used a high pressure poly-type tube that came with my kit. Nice and light and easy to position. Do you have the masters in the front? I used stainless steel braided hose from the fuselage to the wheel. This line did not come with the kit. Bulkhead fittings where the lines penetrate the fuselage. I also have no brake pedals or rudder pedals in the back. No stick or throttle either.

Spinner,

I'd agree with you on no pedal or stick but I need to do some instruction on stick and tail wheel for my kids so I need the backseat pedals and stick. They have only flown my C-170 so the stick is new to them. I may pull them out once they are comfortable and I feel OK with them flying the LSA, but then it is nice to be able to hand off the plane to a pax too or just get a break for a few minutes.

Lowrider
03-24-2013, 09:43 PM
Folks,

From this point forward I would like for everyone to understand that I am no longer building a Bearhawk LSA, rather an LSA of my own design and for clarification, let's call it the Lowrider LSA. NO one should be encouraged to make any modifications or changes to existing Bearhawk plans based upon my comments, actions or recomendations. While I am building under the supervision of a current A&P, I have made design changes that mirror supercubs and other cub like aircraft and hopefully these will result in a good performing plane that will serve my mission in a safe and effective manner.

Thanks for your understanding and your continued support on my project.

Super11XP
03-24-2013, 10:17 PM
0-320???!!!!

Lowrider
03-25-2013, 12:21 AM
Clint,

Many things that I'm changing such as gear, axle, brakes and wheel upgrades, seaplane door, float fittings, extra bracing and increase in tube size and spars, use of a balanced tail and additional bracing in the tail and the consideration of using flaps and an 0-320 powerplant all are changes to the Bearhawk LSA plans so it will be substantially different from the vanilla Bearhawk LSA so it is appropriate to change the name to Lowrider LSA. I believe it will serve my needs and wants better than the original design and still come in under a practical LSA weight. I still believe the FAA should approve the "no medical" Recreational Pilot initiative and if it comes about I can upgrade the gross weight and gain back some useful load....if not, I still have an overweight LSA.

Since I changed majors 3/4 of the way thru a civil engineering degree because I was so bored I couldn't stand it...I'm not qualified to design anything so I ask that no one follow my lead in building my LSA. I am using accepted methods used a variety of certified aircraft in my construction but they are not tried and proven...YET!

To answer your question...it's becoming more than a Bearhawk LSA, thus the name change.

Lowrider
03-25-2013, 08:59 PM
Rudder pedal connections made between the front and rear pedals. Also got tired of looking at a naked tail post so I contoured the vert. stab and welded it up to the tail post. Looks much less naked now.

Dave Calkins
03-26-2013, 02:13 PM
I'm putting brakes only on the front pedals. .

Glad to see you moving, making decisions, and customizing your ride....LowRiderLSA

If you're instructing from the back seat, you may wish to have brake pedals there...........consider a scenario where the instructor allows the student to "get WWAAAYY out of shape" before correcting them............this scenario would make more sense if the instructor had brake pedals and the student did NOT.......or maybe adjustable stops so a student could not overcontrol brakes or rudder,,,,but the instructor would have full throw...it might be appropriate for a new tailwheel student in the first couple hours of instruction.

...just a thought.

PS.....LowRiderLSA..........I even like the name!! D

Lowrider
03-26-2013, 07:29 PM
Glad to see you moving, making decisions, and customizing your ride....LowRiderLSA

If you're instructing from the back seat, you may wish to have brake pedals there...........consider a scenario where the instructor allows the student to "get WWAAAYY out of shape" before correcting them............this scenario would make more sense if the instructor had brake pedals and the student did NOT.......or maybe adjustable stops so a student could not overcontrol brakes or rudder,,,,but the instructor would have full throw...it might be appropriate for a new tailwheel student in the first couple hours of instruction.

...just a thought.

PS.....LowRiderLSA..........I even like the name!! D

Dave,

Thanks for the comments and for keeping up with my antics!

Ordinarily, I would agree with you on the brakes but the only ones I'll be teaching are my kids who are accustomed to my 170 using the yoke and I'm really just learnin them the stick part....I think. They do need to be slapped once in awhile with a stern "center the ball" but mostly they are capable. I tell my middle son he was conceived in a 185 at FL120 over St Augustine and I needed O2 afterwards. He doesn't believe me but then he was born in Homer.

Lowrider
03-27-2013, 09:26 PM
Anyone have any experience with the Thermal Arc 186 TIG or the Lincoln TIG 175?

I think I have made up my mind to invest in a TIG and learn how to use it. There are lots of applications in the airplane and it seems like a useful skill to have. I have been MIGing aluminum with a spool gun but I can't build gas tanks and the like with that set up and doing stainless would also be an advantage so the TIG may be worthwhile.

Also, which works best for you, hand or pedal control? The TA 186 comes with both but the Lincoln only comes with a foot pedal and the hand wheel is a optional item, other than that they are pretty comparible.

Any comments from you TIGgers will be apprecitated.

jimboflying
03-27-2013, 09:49 PM
I have both a Miller 250 and a Thermal Dynamics TIG setup. The newer inverter technology seems to be easier for a rookie like me. I find that I use the foot controller the most but there are times when the hand control is really nice to have. Having pulse capability helps me on thin materials.

Dave Calkins
03-28-2013, 12:37 AM
I have a Lincoln square wave 175.

Lowrider
03-29-2013, 11:15 AM
I bought the Thermal Arc 186 yesterday based upon a variety of recommendations to include my IA mentor. It appears to be a fine machine and I went with it mostly because of the features it has like hand and foot control, pulse and it's an inverter vs transformer based. It's about the same size as my Lincoln SP 180T which going to sell and the TA 186 will go on that cart with my argon bottle.

Number 2 son and I are getting a crash course on TIGing tomorrow from a local TIG expert...lots of CM tube practice before I go near the plane....wondered what I was going to do with all the wind chimes.

Lowrider
03-30-2013, 10:58 PM
Well, following almost 5 hours of TIG training this afternoon I feel VERY humble. Nothing to this TIG thing if you can walk, rub your tummy, pat your head and hop on one foot alternately all at the same time. I have the utmost respect for TIG welders now and I thought I was pretty much Sierra Hotel on the gas torch, stick and MIG. We learned a lot today but the two things that stick out the most are:

1. Inverter based TIG beats the transformers hands down.
2. $450 helmets beat the pants off $150 helmets.

I'm going to bed tonight repeating to myself.....it's all about the heat...when, where and how much....until I fall asleep.

Happy Easter to everyone!!!

Lowrider
03-31-2013, 10:01 PM
I got my wing ribs from Usher Percision thru Mark at Avipro and they look really nice. I did not get a packing list so I couldn't inventory the boxes but they did come damage free and well packaged.

I compared them to the 35B cub rib I got from Carlson and they are not all that much different in overall profile but there are differences in the web and cord so I'm anxious to get the fuselage off the table and start my spars. I found a local 10 foot brake so I'll be ordering materials for the spars soon.

Update on TIG practice...I didn't get any better while I was sleeping. I was able to run a fairly nice bead around two pieces of .035x 3/4 that I was joining together...well almost around...well... 2/3's around before burning a hole.

Lowrider
04-02-2013, 08:56 PM
10893

Anyone think 6 lbs 2 oz is too heavy for the front seat? That includes clecos and the bottom of the seat also has the slide rails attached but I thought I read that folks were getting Cub seats down to 2 or 3 pounds...I guess with mesh seats. CUshion will add more weight. The frame is 4130.

Dave Roberts
04-02-2013, 09:59 PM
Seems a little heavy. Have you thought about using heavy weight Polyfiber or Ceconite on the seat bottoms. That is what a lot of builders are putting in their Bearhawks and Patrols now. I weaved aluminum strips in mine, before the fabric idea came up. Mine weighed a little less than 9 lbs with cushions and upholstery. If I were doing it again I would try the fabric idea.

Dave

Lowrider
04-02-2013, 10:25 PM
Dave,

I have a roll of 2" wide nylon strap that I thought about using on the back since it doesn't hold a lot of weight but everytime I picked it up it seemed heavier than the .025 6061. I may try to find a small piece of polyfiber and play with that some. I could cut some lightening holes in the alum. but I think the weight may be in the 4130 and not the alum. I threw out the idea of using seat jell because it is really heavy but it feels so nice on your butt after 12 hours on the Harley. I have some time to look around but the fabric idea is worth pursuing....thanks!

Lowrider
04-07-2013, 11:32 PM
I went heavy with the fly cutter and reduced the weight of the front and rear seats by 18 ounces total. It took about 2 hours to do the deed so it was well worthwhile to me.

Started working on the nose ribs and it became apparent quickly that I need to set up a production line to get the ribs ready to start setting them up on the spars. Lots of metal bending and riveting to be done on the wings so I guess it is time to get organized.

Several builders got into a discussion yesterday regarding whether or not the use of flush rivets on wings (planes) are really an advantage at the relatively slow speeds that cubs and cub like planes fly. There was not any real agreement so I thought I would throw out the question to you folks who build mostly fabric covered planes and see what you think....any thoughts out there....426 or 470???

Dave Roberts
04-07-2013, 11:40 PM
That might be a question for the designer. I know flush rivets when dimpled are stronger. Did the designer figure that in when he designed the airplane and use less rivets? Personally I would go flush just because I like the nice smooth skin.

Dave

Marc Davis
04-07-2013, 11:47 PM
I went heavy with the fly cutter and reduced the weight of the front and rear seats by 18 ounces total. It took about 2 hours to do the deed so it was well worthwhile to me.

Started working on the nose ribs and it became apparent quickly that I need to set up a production line to get the ribs ready to start setting them up on the spars. Lots of metal bending and riveting to be done on the wings so I guess it is time to get organized.

Several builders got into a discussion yesterday regarding whether or not the use of flush rivets on wings (planes) are really an advantage at the relatively slow speeds that cubs and cub like planes fly. There was not any real agreement so I thought I would throw out the question to you folks who build mostly fabric covered planes and see what you think....any thoughts out there....426 or 470???

One of my older aerodynamics texts says drag has a significant effect on acceleration during the takeoff roll. I'd have to dig the info back up to get more exact information but that would seem like the kind of thing a cub driver would care about, especially one with a limited HP budget.

skywagon8a
04-08-2013, 06:08 AM
It probably won't make a lot of difference in your application. I would use the 426s with dimples on the leading edge back as far as the spar. Then either one for the rest of the wing. You likely will never know the difference however, you will have the satisfaction that you put your best foot forward and it will look better. Also it will be easier to clean off the bugs.

I used 426s on the bottom forward section of a flying boat once. It did make a difference. It was more slippery in the water.

don d
04-08-2013, 11:53 AM
I used heavey duty fabric for seat bottoms and backs on my lsa. double up on regular wieght would work also. Not bad to sit on even without cushions.. Save the wieght everywhere you can.I never tried countersinking aluminum less than .032... would get pretty thin.Don

Lowrider
04-09-2013, 12:05 AM
Thanks for the responses on rivets...pretty much mirrored the comments I heard previously. Funny that I heard the "bugs" comment from 2 different folks but I gotta agree that could be a factor. Some suggestions were to use the heavier than .016 skin on the leading edge and dimple for 426's and that makes sense to me. I think using .025 from bottom of spar to top of spar would save some effect from hanger rash and even heavy rain, not to mention those giant grass hoppers I've seen around here. Dimpling and flush riveting is no fun on thin material and that makes me want to go one size bigger too. Maybe it's easier for everyday riveters but I find it very easy to get those little oooppps marks on the skin. I know it will cost me some weight...think it's worth it for stiffer/heavier leading edge??

Dave Calkins
04-09-2013, 11:58 AM
...I think it it "easier" to dimple thinner stuff. Don't think that you have to "SMUSH" the metal.......try a bit lighter touch and your results will be nice. You need to have a light touch and support the gun when riveting light metal also.

There is no question that dimpled skins are stronger than not dimpled and much, much stronger than countersunk.

The first advantage of flushed rivets that came to my mind when thinking of your LSA was "removal of bugs" :)

PS........ My findings with bonding skins.......3M 5200 marine sealant is as good as rivets!!!! WEll, in a certain way...............Many, many times when I need to take apart something that is riveted and sealed with 5200, if there is 5200 on the faces of the skins, I drill out the rivets and the skins are very difficult to pull apart!!!!!

...just saying.

8GCBC
04-09-2013, 12:10 PM
3M 5200 is unreal. Bonded surfaces will most likely NEVER come apart again. This week I am re chaulking port holes on the sailboat with 3M 5200. Should be good for another 30+ years on the ocean 8)

USE 3M 4200 if there is any chance that the surfaces may need to separate ( with out destruction )!

Lowrider
04-09-2013, 03:02 PM
Yes Sir!! 5200 is great!! I just fixed an ATV fender with it...stuck it together, put some 5200 in the break and smeared it on the back side....a week later and it is like new....sorta.

What's your thoughts on .025 for leading edges rather than .016 or .020?? Yes, harder to bend and heavier...is it worth it? Should withstand bug strikes better!!

Dave Calkins
04-09-2013, 04:46 PM
....bug strikes??

..you must be taking that airplane where those HUGE moth's grow!

I'd keep the wing design on something like this (full metal wing?!) as the designer figured it.

Also, setting ones mind to saving weight (or keeping weight where the designer want's it) must stand on principle if that's what you start with.

..otherwise, you end up with 'just another fat cub'.

...funny...... fat cubs with proper wing incidence fly great. Fat Cubs with incidence, slats, and big flaps haul a load better than skinny cubs.

....so, here we are again asking what you want!!!?!!!

Lowrider
04-09-2013, 09:21 PM
Dave,

Still not a big as the AK skeeters!!

I want a medium weight LSA that's tough and performs well at high density altitude...just looking for ideas on how to do it...horsepower, yes/no, flaps, yes/no, HD gear/brakes, yes/no. I don't want to get it in the air and regret doing something that seems like a good idea and wasn't pursued. Maybe a light plane with no flaps is the answer but I want to be able to takeoff from a 6K foot field at 80 degrees with no problems.

Lowrider
04-09-2013, 09:26 PM
Dave,

Still not a big as the AK skeeters!!

I want a medium weight LSA that's tough and performs well at high density altitude...just looking for ideas on how to do it...horsepower, yes/no, flaps, yes/no, HD gear/brakes, yes/no. I don't want to get it in the air and regret doing something that seems like a good idea and wasn't pursued. Maybe a light plane with no flaps is the answer but I want to be able to takeoff from a 6K foot field at 80 degrees with no problems...other than that I want to put it on floats too...kinda points to HP and flaps to me. What do you folks think?

marcusofcotton
04-09-2013, 10:01 PM
What's your thoughts on .025 for leading edges rather than .016 or .020?? Yes, harder to bend and heavier...is it worth it? Should withstand bug strikes better!!
I seem to recall reading that Bob Barrows used .016 for the wings but doesn't recommend it for others, unhappy with results and harder to work with, IIRC.

Thanks for sharing your build, very truly an inspiration for this slooow BH builder.
Mark J

don d
04-09-2013, 11:09 PM
my LSA is so slow that I worry about bird and bug strikes from the rear

Lowrider
04-10-2013, 09:04 AM
Mark,

Thanks for the comment...I'm trying to inspire myself while unpacking from my move, buillding a green house, an extra bedroom, getting a boat ready for the Spring and function testing a variety of fly fishing gear...among other things. Glad I'm retired so I have time to do all this stuff!!

Don,

When I first joined the EAA chapter here one of the first safety lectures was on emergency landings. One slide was entitled "Avoiding potato bugs" which of course live in the ground...something I've avoided running into for 45 years next month. Low and slow suits me just fine...fly safe!!

Lowrider
04-11-2013, 12:06 PM
OK, Let's talk gear length....I keep seeing recomendations to use a +3" extended gear on cubs to gain a 1.5" advantage in prop clearance. I really don't see that as a major benefit depending upon what engine/prop combo is mounted and where it's mounted on the nose. If I go with an 0-320 I will most likely mount it as close to the firewall as practical to keep the CG where it should be. That will reduce prop clearance to some unknown degree. If I go with an 0-200/C-90 that will be less of an issue. Either way, I'm planning stout mains and a beefy tailwheel. I don't want to mow knee high grass and I understand that tires are also a big factor in prop clearance. I'm planning on 21"x6" or larger but may end up with 6.00x6" for weight.

Questions:

Is there something magic about 3"?

Why not 4" or 5" or 6" or more?

How much extra stress does the extended gear place on the fuselage bottom longerons and mounting points?

Is it better to gain prop clearance with tires than extended gear?

Lowrider
04-15-2013, 09:38 AM
Laid out and welded the rudder with the TIG...sure is slow compared to the MIG or the gas torch. It does allow very percise heat control and as my (and #2 son) experience increases we are able to do acceptable welds, I believe.

Any thoughts on previous post????

qsmx440
04-15-2013, 10:03 AM
OK, Let's talk gear length....I keep seeing recomendations to use a +3" extended gear on cubs to gain a 1.5" advantage in prop clearance. I really don't see that as a major benefit depending upon what engine/prop combo is mounted and where it's mounted on the nose. If I go with an 0-320 I will most likely mount it as close to the firewall as practical to keep the CG where it should be. That will reduce prop clearance to some unknown degree. If I go with an 0-200/C-90 that will be less of an issue. Either way, I'm planning stout mains and a beefy tailwheel. I don't want to mow knee high grass and I understand that tires are also a big factor in prop clearance. I'm planning on 21"x6" or larger but may end up with 6.00x6" for weight.

Questions:

Is there something magic about 3"?

Why not 4" or 5" or 6" or more?

How much extra stress does the extended gear place on the fuselage bottom longerons and mounting points?

Is it better to gain prop clearance with tires than extended gear?

Isn't the slight advantage to angle of attack during take off as one of the reasons given ? A slight change in angle of incidence would make more difference when building but a long tail dragger is at a disadvantage AOA on the ground.

A longer prop is much more efficient at low speeds.

Lowrider
04-15-2013, 10:22 PM
I beieve there is a slight advantage in AOA with longer gear but my reason for wanting it is prop clearance. I am concerned about the increase leverage due to longer gear and that is one of the questions I have....is it really worth it?

I will follow Mr. Calkins' suggestions regarding AOI.


We laid out and TIG welded the horz stabs and elevators today and we're still waiting for the ribs from Avipro to finish up the rear control surfaces.


Any other throughts on extended gear?

spinner2
04-15-2013, 10:37 PM
I beieve there is a slight advantage in AOA with longer gear but my reason for wanting it is prop clearance.

Any other throughts on extended gear?

My opinion is that the real advantage of extended gear and especially when combined with tall tires is that allows you to takeoff and land at a higher AOA while keeping the tail wheel off the ground. High AOA means slower landing speeds and resulting shorter ground roll. On takeoff it facilitates getting the tail up, but not so much that it reduces desirable AOA when it is needed.

This probably isn't much of an issue unless using unimproved landing areas.

Prop clearance is another benefit but not the most important IMO.

Larry G
04-16-2013, 07:50 PM
Lowrider do have any pictures you can post.



We laid out and TIG welded the horz stabs and elevators today and we're still waiting for the ribs from Avipro to finish up the rear control surfaces.

Dave Calkins
04-16-2013, 11:10 PM
My opinion is that the real advantage of extended gear and especially when combined with tall tires is that allows you to takeoff and land at a higher AOA while keeping the tail wheel off the ground. High AOA means slower landing speeds and resulting shorter ground roll. On takeoff it facilitates getting the tail up, but not so much that it reduces desirable AOA when it is needed.

This probably isn't much of an issue unless using unimproved landing areas.

Prop clearance is another benefit but not the most important IMO.

I am not convinced that longer gear "...facilitate getting the tail up..." for takeoff.

Lowrider
04-16-2013, 11:48 PM
Larry,

I have fallen down on my photo responsibilities and I will try to fix that tomorrow. I'm not terribly qualified at picture posting...you would think a COM IA MEL CFI could handle something so simple...well...not so much.

It seems I have a leak in my new TIG setup....Thursday of last week I refilled my argon bottle and this morning it was almost empty. Took it to the argon store and explained the problem and they said it must be a leak. I assured them we have not been welding 24/7. They gave us a loaner bottle and leak checks all around in the morning.


Dave,

I must agree...moving the main axles forward would put more weight on the tailwheel and require more tail lift to get it up so it would seem forward extended gear would slow take off. Does it make enough difference to make forward extended mains a bad idea?

spinner2
04-17-2013, 08:48 AM
I am not convinced that longer gear "...facilitate getting the tail up..." for takeoff.

I didn't mean to say that longer gear made it easier to get the tail up. What I meant to say was that longer gear allows the pilot to get the tail off of the ground during the takeoff roll but still keep a decent amount of AOA in for maximum lift.