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Lowrider LSA

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.
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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?
 
Crash said:
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
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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.
 
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.
 
mvivion said:
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
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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.
 
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????
 
Lowrider said:
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. ??
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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.
 
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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.
 

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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!
 
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 said:
Looks like the date on your camera is off ;) Nice work
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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.
 
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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.
 

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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?
 

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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....
 
Lowrider said:
Has anyone built an A frame tail wheel with a coil over shock for suspension?
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Here are some samples:

th
th


Stinson Model T
800px-Stinson_Trimotor.jpg


Travel Air S-6000-B
01_Travel_Air.jpg
 
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...
 
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 said:
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?
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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.
 
Last edited:
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
 
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
 
Mark Goldberg said:
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
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What were the particulars about the "contest"?

Wind? Takeoff roll length for each? Temperature? ...stuff like that???
 
Lowrider said:
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?
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The new Just Highlander Super STOL has that... Saw a pic of it posted I think on on BCP...

Brian
 
Steve's Aircraft (Steve) said:
The new Just Highlander Super STOL has that... Saw a pic of it posted I think on on BCP...

Brian
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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.
 
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
 
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.
 
Cub junkie said:
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.
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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!!
 
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