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RVBottomly
12-02-2017, 08:43 PM
Therapy time for me. I’m a sole-practitioner public defender and this has been an extraordinarily hard year. I just finished up a very hard trial and have another in 4 days. As I mentioned in the “Cry for Help” thread, I’m working to scaling back all of this in the coming year. I intend to divert some of that energy into building an airplane.

So, after agonizing, reading, ordering, and reviewing plans, (including shortwing disks and Northland Supercub drawings, etc.), I followed the suggestion of jimboflying and others--I ordered some materials from Wicks and started building tail feathers.

I’m pretty much settled on a Wag Aero 2+2. Many thoughtful people encouraged me toward a Super Cub, but my wife is fully on board with a side-by-side project. The other fleeting option would be a Wagabond with flaps, somewhat extended fuselage, and an O-233 or even an O-290.

But, I see floats in the future, and the 2+2 obviously is comfortable with those.

I spent 4 hours messing about in the shop and got a start:

33870

33869


I freehand bent the tube around my shop stump:

33871

I already see things I need to change. For one thing, I will be looking for a better torch. My gas welding has come back after 25 years, but the consumer-grade regulators and clunky “all-purpose” torch handle are geared more toward cutting angle iron.

I’ll also improve jig arrangement and probably add some upper-level storage.

But it’s a beginning. Maybe, after next week’s trial, I’ll put together some elevators. And then, wait for more material and do whatever seems good to do next. It’s pleasant in my heated shop, too cold to fish anyway. If I rejigger my world for the coming year, I might even have some 20 hours a week to put into the project.

brown bear
12-02-2017, 09:00 PM
RV
Looks like a great start ! I got along fine with "consumer-grade regulators " but found this torch a "must have" when building my plane .
Doug
http://www.aircraftspruce.com/catalog/topages/smithstdtorchhand.php?clickkey=44051

RVBottomly
12-02-2017, 09:12 PM
found this torch a "must have" when building my plane .
Doug
http://www.aircraftspruce.com/catalog/topages/smithstdtorchhand.php?clickkey=44051

Yes, I've been looking at that for a while. I've never actually handled one, but have heard good things.

Vic

Gordon Misch
12-02-2017, 11:04 PM
Suggestion - visit your local welding supply house and ask what model the pros mostly buy.

Cub junkie
12-03-2017, 01:13 AM
If you want a first class torch for aircraft ox/acet welding check out the Meco Midget sold by Tin Man tech.

jimboflying
12-03-2017, 02:25 AM
Vic,
Congratulations on your decision and start. Building a plane is only one part at a time. Celebrate each part and then each page completed of the drawings. Eventually there are no more parts to build and no more pages. I too am building a 2+2 which is a PA14 replica. I had an original PA14 and found it to be a great plane. You might consider building a really flat and sturdy workbench to work on. I used floor joists and 2 layers of thick flooring material screwed to the top with 4X4 legs. Mine is 16’ long so you can build the fuselage straight and true. I also second the Meco torch but you might consider Tig as well. The money you save by building your own will justify lots of new tools. Good luck and keep us posted.

Cub junkie
12-03-2017, 09:31 AM
Here is something similar to what jimboflying is describing. Mine is 18 ft long. I use 3/4 particle board and change the top occasionally. Particle board is flat and cheap.

mike mcs repair
12-03-2017, 04:32 PM
buy a Tig, with a finger controller.....

RVBottomly
12-04-2017, 09:04 AM
Vic,
Congratulations on your decision and start. Building a plane is only one part at a time. Celebrate each part and then each page completed of the drawings. Eventually there are no more parts to build and no more pages. I too am building a 2+2 which is a PA14 replica. I had an original PA14 and found it to be a great plane. You might consider building a really flat and sturdy workbench to work on. I used floor joists and 2 layers of thick flooring material screwed to the top with 4X4 legs. Mine is 16’ long so you can build the fuselage straight and true. I also second the Meco torch but you might consider Tig as well. The money you save by building your own will justify lots of new tools. Good luck and keep us posted.

Thanks for the encouragement. I'm working on a flat and sturdy platform with locking casters to move it around. I built a "strongback" on my boat project 2 years ago, and I still have material from that. I still need to organize space a little.

I see all sorts of people endorsing the Meco torch, from you and Cub Junkie and Christian Sturm. I'm leaning that way, even without trying one out.



Here is something similar to what jimboflying is describing. Mine is 18 ft long. I use 3/4 particle board and change the top occasionally. Particle board is flat and cheap.

I like how you've clamped things down. Looks very tidy.


buy a Tig, with a finger controller.....

Right. I should get with the late 20th century. But I'm curmudgeonly smitten by the therapeutic value of the gas-torch-weld-puddle-dance. It's sort of like an old guy trying the hula hoop. At least until my hands go too numb and my back gets too stiff.

Vic

aktango58
12-04-2017, 01:56 PM
Right. I should get with the late 20th century. But I'm curmudgeonly smitten by the therapeutic value of the gas-torch-weld-puddle-dance. It's sort of like an old guy trying the hula hoop. At least until my hands go too numb and my back gets too stiff.

Vic[/QUOTE]

Tig uses the same puddle dance. Instead of having flammable gas, you have one intert gas- plus the torch tip is quicker to clean if you have a belt sander.

JP
12-04-2017, 03:29 PM
Therapy is good. J'approve.

RVBottomly
12-04-2017, 03:57 PM
Tig uses the same puddle dance. Instead of having flammable gas, you have one intert gas- plus the torch tip is quicker to clean if you have a belt sander.


Well, yeah. You and Mike and many others speak truth on advantages, but I have to look at my own nature. If I get one of these TIG gadgets, next thing happening is I'll want to do a bunch of pretty welds, which will lead to starting on custom intake manifolds for some hot-rod I don't own, which means a bigger shop, which means the airplane won't get done....


Etc....



Therapy is good. J'approve.


Merci! Et je suis d'accord.

Vic

Lowrider
12-07-2017, 10:05 PM
Welcome aboard!
I have a Meco with a variety of tips and I use the light weight hose that really cuts down on arm/hand fatigue. You certainly need a TIG for steel and aluminum and I find I use my Lincoln 180 MIG a lot too. Sometimes just to make a quick jig or whatever and I don't feel like fooling with gas or the TIG. MIG be quick and only takes one hand. You need foot and finger control for the TIG. Also, go into the kitchen and steal the old cookie sheets to put between the tube and the wood when your welding on top of the wood. Also, paint your table top flat white...makes things easier.

RVBottomly
12-08-2017, 02:33 PM
Thanks for the welcome, Lowrider. I've enjoyed reading about your project.

But I'm supposed to get a MIG, too? It took me 30 years of Lincoln AC buzzbox welding before I could finally convince myself to get a used Miller AC/DC stick welder. I'd been wanting one of those since high school and finally got one a few years ago. For me that's a quantum leap!

As for the cookie sheets, it would be a major challenge to pry those from my wife's grip. But leftovers of 22 gauge steel from making ribs seems to work pretty well.

Lowrider
12-08-2017, 03:22 PM
No Sir...you don't need a MIG...you can do it all with the torch or the TIG... Buzz box...not so much.
Ref cookie sheets...I convinced my wife the old ones were possibly leaching alum molecules into the cookies and stainless steel would be much healthier and probably make the cookies taste better...worked well...feel free to use it if it fits.

RVBottomly
12-09-2017, 08:58 PM
Got through another week. Did some house chores, and got one elevator formed. I was hoping for two, but I remind myself I'm not on a clock for the project. Line by line, here a little, there a little...etc.

33982

33983

33984

I still need to weld up collars and form horn assemblies. I'm waiting on another material order to proceed on that.

And I still haven't ordered a different torch. The Victor-styled medium duty torch works alright for now. All week I was pretty heavily occupied until this morning.

So far I'm learning quite a bit about metal working. The 3/8 tubing bends OK free handed, if you are very careful. The elevator shape could use a bit more fairing--then again, I've seen some pretty odd looking tail feathers at the airport.

aktango58
12-09-2017, 11:17 PM
Looking good!

Each welder has it's own place- a small Tig like MIller's Diversion 180 will give you a whole lot of options. I bought the finger control after watching gyrations of guys welding inside aircraft with foot controls. Duck taping the controller to your foot just seemed silly when I could be laying down and just flex my finger.

Keep up the great work there, and posting pictures. Should be a fantastic project, once finished fun to fly.

dgapilot
12-10-2017, 09:49 AM
For torches, the Meco or the AW1 are both good alternatives. Try wheat works in your hand. I use a couple 1940 vintage Smith #2 torches, one was my grandfathers, the other I got on eBay recently with a bunch of “V” tips - soft flame for welding aluminum. The #2 is the predecessor of the AW1, but the tips aren’t interchangeable. The super flex hoses make a big difference in hand fatigue. Check out “the tinman” web site.

I’ve also got an Everlast 210EXT welder for TIG. Some stuff is more natural with the torch, others with the tig. The welding hood is harder to maneuver around in the fuselage than just a set of goggles. Either way, you can do quality welds that will keep your airplane together.


Sent from my iPhone using Tapatalk

Hardtailjohn
12-10-2017, 09:08 PM
RV
Looks like a great start ! I got along fine with "consumer-grade regulators " but found this torch a "must have" when building my plane .
Doug


I've had my Smith torch since the mid 80's and love it!! I got my powerplant rating at Watertown, SD where they're made. One of my classmates' wife was a demo-welder for Smith back then... she could really weld with a torch!! We all ribbed Randy about not being as good as her.
At any rate, you'll love the Smith! Small, handy and still big enough to do what ever you need done!
John

RVBottomly
12-10-2017, 10:09 PM
Thanks dga and John. I found out one of our local weld supply shops carries Smith in stock. I'll take a look at one when I get a chance.

RVBottomly
12-10-2017, 10:32 PM
Duck taping the controller to your foot just seemed silly when I could be laying down and just flex my finger.



I studied up on TIGs a bit to see what you were talking about. I'll have to agree!

Southern Aero
12-12-2017, 10:29 PM
RV

FWIW, You have to decide how much you want to spend both money and time learning to weld........... Oxy-Acet is the lest expensive to get into and isn't too hard to learn. Getting "pretty" welds takes some practice. If I use MIG its only to tack up a project for convenience and use a small Lincoln, .023 wire and teflon liner with small torch. MIG is structurally OK but tends to leave welds unsealed even it the best hands. ....... Your Tube Seal will point this out quick. Gas welding is what I use most and don't see any drawback other than having to clean up more with the sand blasting. Things "move around" a lot more with gas but once you learn it, there are a lot of things you can do to prevent distortion. ....... Plus it's "traditional". TIG is the first choice for a lot of guys but I use it mostly for sub assemblies. For me its too cumbersome for getting around in a fuselage but it sure makes a clean weld. ......... The AW1 "Airline" torch as mentioned before is my preference with 3/16" light weight/flexible hoses. High dollar 2 stage regulators are nice but not necessary. I have tried the real short light weight Victor and a pistol grip Henrob and never use either one of them. So, I guess I would say I prefer gas over the electrics for most airframe work. Maybe its because I pissed on an electric fence when I was a kid and never got over it?? Plus you can weld when the power is off!

mike mcs repair
12-12-2017, 10:35 PM
I've had my Smith torch since the mid 80's and love it!!
John

smith is what I have too... but the last time i used them to weld was in 2004(still on that same set of bottles..), and that was just so I could remember how to Oxy weld, after becoming spoiled by TIG.... night and day...

RVBottomly
12-12-2017, 11:10 PM
RV

FWIW, You have to decide how much you want to spend both money and time learning to weld........... Oxy-Acet is the lest expensive to get into and isn't too hard to learn. Getting "pretty" welds takes some practice. If I use MIG its only to tack up a project for convenience and use a small Lincoln, .023 wire and teflon liner with small torch. MIG is structurally OK but tends to leave welds unsealed even it the best hands. ....... Your Tube Seal will point this out quick. Gas welding is what I use most and don't see any drawback other than having to clean up more with the sand blasting. Things "move around" a lot more with gas but once you learn it, there are a lot of things you can do to prevent distortion. ....... Plus it's "traditional". TIG is the first choice for a lot of guys but I use it mostly for sub assemblies. For me its too cumbersome for getting around in a fuselage but it sure makes a clean weld. ......... The AW1 "Airline" torch as mentioned before is my preference with 3/16" light weight/flexible hoses. High dollar 2 stage regulators are nice but not necessary. I have tried the real short light weight Victor and a pistol grip Henrob and never use either one of them. So, I guess I would say I prefer gas over the electrics for most airframe work. Maybe its because I pissed on an electric fence when I was a kid and never got over it?? Plus you can weld when the power is off!

I'm committed to gas welding. I learned the basics in the 70s in high school shop and kept it up through the 80s on things from thin sheet metal to plow repairs in the field. The only other welding I'd ever done was stick arc welding, though I played with an electric carbon arc a little bit. I'm happy "relearning" an old skill. I like the review on the Meco, but I'll probably choose the Smith because of nostalgia, if nothing else.

BTW, I was kidding about a MIG. I don't really think I need one. I'm working on reducing clutter in the shop and not inclined to add more equipment I don't need.

But guys like George and Mike keep encouraging me down the road toward TIG. They'll probably eventually succeed, but probably not until I've welded up most of a fuselage. I'm sort of happy reliving my second childhood...at least for now.

As for the electric fence--I've had the exact same experience.

Vic

RVBottomly
12-23-2017, 05:42 PM
Slow steps forward. I spent the morning fabricating a rudder horn out of .090 4130 plate. It took a couple of tries--the first time I followed the cut lines suggested by the WagAero plans, and when I bent the tabs, they did not come up parallel with the rudder tube. In hindsight it should have been obvious, but hindsight often is not foresight.

I got my start taking a pdf from the Northland drawings, turning it into a jpg, and putting it into a MS Word document so I could adjust the size. I ended up with a perfect full-size template to lay things out.

http://rvbottomly.com/wp-content/uploads/2017/12/20171222_150140.jpg

Then it was a matter of drilling, bending, trimming, and welding.

http://rvbottomly.com/wp-content/uploads/2017/12/20171222_152526.jpg

http://rvbottomly.com/wp-content/uploads/2017/12/20171223_093839.jpg

http://rvbottomly.com/wp-content/uploads/2017/12/20171223_094612.jpg

http://rvbottomly.com/wp-content/uploads/2017/12/20171223_100040-1.jpg

http://rvbottomly.com/wp-content/uploads/2017/12/20171223_1335411602607860.jpg

In the photo just above the last one, you might notice the horn is on backwards. I started to tack it that way and then had a little alarm-feeling. The drawings don't make it obvious.

But I had bookmarked Bill Rusk's build thread on my phone, so I could look at pictures. Sure enough, there was a sequence of nice rudder photos.

Armed with that information, I ground out the tack and set it right. Thanks Bill! You probably didn't even know how much pain you saved me.

Next step will be elevator horns and bending the 1" stabilizer leading edge tubes.

RVBottomly
12-25-2017, 05:41 PM
Shoveled the Christmas snow and had a few hours in the morning. Elevator horns:

http://rvbottomly.com/wp-content/uploads/2017/12/20171225_081558.jpg


http://rvbottomly.com/wp-content/uploads/2017/12/20171225_082850.jpg

After match drilling and before further grinding:

http://rvbottomly.com/wp-content/uploads/2017/12/20171225_124852.jpg

Aligning. It seemed easier using the floor because it was clear at the moment.


http://rvbottomly.com/wp-content/uploads/2017/12/aligning-horns.jpg

Tacking:

http://rvbottomly.com/wp-content/uploads/2017/12/align-closer.jpg

http://rvbottomly.com/wp-content/uploads/2017/12/tacked-horns.jpg

The snow is picking up again. I'm going to have to get the little plow going before dark. Therapy project set aside for another day.

RVBottomly
01-01-2018, 09:19 PM
Happy New Year! I hung up my new Supercub calendar, had a day off, and spent part of it working on stabilizers.

Well, the plan was to work on stabilizers, but I only worked on one. Things took a lot longer than expected.

And I learned some things, which is good, because I can continue to certify compliance with CFR §21.191 (g) ("undertook the construction project solely for their own education or recreation").

So, I learned that bending 1" 4130 is harder than I thought, even when filled with tamped sand. My first try ended up with a kink despite my efforts at using a nice round curved log. I got the bend pretty close, then I tried fitting it into my tabletop jig. One little extra push...Oops.

So, try again. This time I got it bent pretty close, slowly and in increments, and finished the bending with my new and improved variable-curved-moveable bending mandrel (cut from a 2X4 with a jigsaw). It seemed like the ticket.

http://rvbottomly.com/wp-content/uploads/2018/01/01-initial-layout-captioned.jpg

http://rvbottomly.com/wp-content/uploads/2018/01/03-first-rib.jpg


I didn't take pictures of fabricating and installing the various ribs. I'd already spent most of the morning getting the 1" spar configured. Basically, I cut sheet metal with electric shears and bent them up with a cheap Harbor Freight brake, profiled them with a grinder, and tacked them up.

http://rvbottomly.com/wp-content/uploads/2018/01/04-aligning.jpg

And put an elevator next to them to see how things fit. That caused me to want to adjust the upper rib angle a bit.

Being too tired and out of time to start the next stabilizer, I switched to cutting up parts for the hinges. The next thing I learned is I want a cut-off grinder. Free handing an angle grinder on these parts is kind of tedious and sloppy.

http://rvbottomly.com/wp-content/uploads/2018/01/05-hingeparts.jpg

Then I turned back to my kinked spar and tried to see if I could salvage it. I put it into a vice and heated the kinked area to force it to expand. I don't know if I can use it. The kink will line up close to a rib. It seems like I could reinforce it with half a tube, but then I'm worried about falling into a barn-yard fix mentality.

http://rvbottomly.com/wp-content/uploads/2018/01/06-unkink.jpg

So, that's the day. I'm also wondering about the hinge pieces. Both the Northland plans and the Wag Aero plans call for steel bushings. Really? Seems like bronze should go there.

But I'm new to all this. I'll follow the plans unless someone says there is something better.

skywagon8a
01-02-2018, 07:23 AM
http://rvbottomly.com/wp-content/uploads/2018/01/04-aligning.jpg

It may just be an optical illusion. Is the stub of the front spar parallel to the rear spar (left side of the picture)? This is important as the stabilizer assembly needs to move smoothly with the trim system.

RVBottomly
01-02-2018, 08:00 AM
It may just be an optical illusion. Is the stub of the front spar parallel to the rear spar (left side of the picture)? This is important as the stabilizer assembly needs to move smoothly with the trim system.They are very close to parallel. It might take some tweaking.

I was thinking of leaving that last rib just tacked until I can get it all assembled to check for fit.

Thanks for keeping an eye out.

Vic





Sent from my SM-J320V using SuperCub.Org mobile app (http://r.tapatalk.com/byo?rid=93960)

CharlieN
01-03-2018, 07:21 AM
I'm also wondering about the hinge pieces. Both the Northland plans and the Wag Aero plans call for steel bushings. Really? Seems like bronze should go there.

But I'm new to all this. I'll follow the plans unless someone says there is something better.

Steel bushings might be OK in the Mojave desert for a month or two, but for us in the rest of the world it is surely not a good choice. I use Delrin as a bushing material, bronze is OK but is rather old school by today's standards.

RVBottomly
01-03-2018, 08:41 AM
Steel bushings might be OK in the Mojave desert for a month or two, but for us in the rest of the world it is surely not a good choice. I use Delrin as a bushing material, bronze is OK but is rather old school by today's standards.

Thanks. I had a blind-spot dumb-out and had transposed reference numbers. Last night I looked again and the Northland plans clearly specify "oil impregnated." Then I started stumbling upon Oilite bushings for sale from Javron and Univair. Inexpensive, too. Finally I ran across Steve Pierce's bushing replacement tool and started to think: "never mind my question...nothing to see, move along...."

But now we talk Delrin? I think I'm really out of the loop. I have used Delrin for harpsichord plectra, and I've seen it on cabinet hinges, but elevator bushings? Sounds interesting.

CharlieN
01-03-2018, 08:56 AM
I started using Delrin as a primary bushing material about 30 years ago. In applications that had a bronze or brass type bush I swapped in Delrin. I have yet to replace a Delrin bush That I have made or was installed by anyone else. The real nice aspect is these are an install and forget, you do not need to lubricate them periodically. In my current build the tube or housing any bush goes in will be stainless but steel is fine if protected by paint or some coating. If not coated then a lubricant should be used if anything just to be a protectant from moisture.

RVBottomly
01-03-2018, 09:17 AM
Thanks, CharlieN. I'll check that out.

Just to vindicate myself a little, I looked again at the Wag drawing and it has the bushing as "3/8 X .065 - 4130". That's what started me wondering about all this.

CharlieN
01-03-2018, 10:16 AM
Thanks, CharlieN. I'll check that out.

Just to vindicate myself a little, I looked again at the Wag drawing and it has the bushing as "3/8 X .065 - 4130". That's what started me wondering about all this.

Not all the pivot parts would always be lined, kind of call it fixed bush and pivoting bush. I have built parts from Wag drawings and have some here but it has been too long that I do not recall their technique. I do recall a few cut corners in some aspects of their builds.
But at least one half of the hinge should be lined with a bearing surface.

RVBottomly
01-03-2018, 10:28 AM
I have the Wagabond drawings too. Exactly the same: 3/8 X .065 4130 for both the "fixed" bushing and the pivoting one.

Then again, I've seen a lot of steel gate hinges last a long time with an occasional squirt of oil. Still, it seemed odd for a control surface hinge.

CharlieN
01-03-2018, 10:40 AM
Not really that odd for the plans to call out unbushed hinges. Myself I would go with 3/8-.058 so they do not need to be reamed and there is room for lubricant.
But then I would never build an unbushed hinge now that I know better.
They would have designed for ease of build, not every welder can attach a short .035 wall tube without collapsing it during the process. The .065 being thicker than the tube you are welding to will hold up better during the welding.

If you consider going with thin wall tube and bushings, use a copper rod inside the tube during the weld process to reduce the chance of collapsing the hinge.
If you are doing the hinge as two fixed and one live tube in the center, the fixed tubes can be thick wall and the center thin with a bushing.

RVBottomly
01-03-2018, 10:57 AM
Just to be clear, the Wag plans have the 3/8 bushing pressed inside a 1/2" x .065 tube.

http://rvbottomly.com/wp-content/uploads/2018/01/hinge-detail.jpg


I like your idea about an insert. I was imagining the varieties of distortion I could come up with.

Vic

CharlieN
01-03-2018, 11:34 AM
Now I remember that, I was questioning in my mind that the gap between surfaces was greater than the 3/8 plus some standoff for bushing clearance.

Gas welding is not hard to attach .065, Tig can hit harder should the flame, "arc" not be directed properly. But a copper insert will be a great help in lining up the outer bushes. The steel tube will shrink a bit as well as having some scaling on the inside such that a copper mandrel should not be tight before the weld.

I will be using Strap hinges on my plane, these are common on Pitts and other performance planes. They close up the gap in the surfaces, you might consider looking into them. The strap hinges are a bit different to build but in some ways easier and they fly a bit better.

Steve Pierce
01-04-2018, 02:00 PM
Don't forget the gussets 11994-18 in your horizontal stabs. Cub Crafters left these out of the Carbon Cubs and then the braces started breaking and rubbing through the fabric. Their SB00018 RevA addresses this. http://legacy.cubcrafters.com/technical_publications/26/view

RVBottomly
01-04-2018, 03:16 PM
Don't forget the gussets 11994-18 in your horizontal stabs. Cub Crafters left these out of the Carbon Cubs and then the braces started breaking and rubbing through the fabric. Their SB00018 RevA addresses this. http://legacy.cubcrafters.com/technical_publications/26/view

Thanks for that! I didn't see anything along those lines in my sets of drawings. The 12769 drawing you attached has more information and detail than what mine has.

The back-watching is much appreciated.

RVBottomly
01-04-2018, 03:24 PM
BTW, I can't find 11994-18 in any of my Northland or other Piper files. I'm assuming it is sheet metal shaped as shown. Do you know if it's 4130 or whether something like 22 gauge mild steel would be sufficient?

Steve Pierce
01-04-2018, 03:35 PM
The shape is pretty obvious but here is drawing 11994 as well. Oh shot, just realized -18 is not included

RVBottomly
01-04-2018, 03:38 PM
The shape is pretty obvious but here is drawing 11994 as well. Oh shot, just realized -18 is not included

Yup, that's what I have.

Well, I think I'll use something that doesn't overpower the channel material that it is being welded to.

CharlieN
01-04-2018, 07:54 PM
I've got another question, have you considered going with an airfoil shape on the tail feathers?

RVBottomly
01-04-2018, 10:29 PM
I've got another question, have you considered going with an airfoil shape on the tail feathers?

I have considered it, and researched it a bit. In the end, I decided to go with stock. It's my first build, after all, and I've got plenty of challenges without also trying to redesign things too much.

Not that I'd be averse to trying them in the future. I'm sort of an inveterate tinkerer.

RVBottomly
01-06-2018, 09:21 PM
Enjoying some spare time, I formed and laid out the second horizontal stabilizer. It went quicker the second time.

http://rvbottomly.com/wp-content/uploads/2018/01/stab-2-layout.jpg

After tacking it up, I put things on the floor with the elevators to see how it all lined up. Not bad, but it required a bit of adjusting.

http://rvbottomly.com/wp-content/uploads/2018/01/stab-alignment.jpg

A bit of grinding away tacks, rejigging, using various means of tension and pressure, and it got pretty close. I also started to add those gussets Steve Pierce mentioned.

http://rvbottomly.com/wp-content/uploads/2018/01/20180106_162653.jpg

I don't think I'll do anything with the hinges until I have a fuselage to attach it to. I have a bit more material to work on the vertical stabilizer.

Then I'm girding up my loins in preparation for the big fuselage material order. Winter is a great time to do this sort of stuff, but I can see winter flying by.

RVBottomly
01-13-2018, 09:11 PM
Another block of time, another step along the way. Today I built the fin.

I didn't take any pictures of the process, but it is fairly straightforward--no bends, just straight lines.

http://rvbottomly.com/wp-content/uploads/2018/01/20180113_174313.jpg

I decided to take a stab at making hinges. The outer bushings are spec'd at 1/2 OD by .065. I was looking around for something I had on hand that might be used to align the bushings (a bit smaller than 3/8"). Turns out the threaded portion of a 3/8 carriage bolt is a nice snug fit.

The inefficient way to start the hinges is to cut each bushing to size and the tack on a little platform from .062 steel plate.

http://rvbottomly.com/wp-content/uploads/2018/01/20180113_143810.jpg

For future hinges, I'm going to steal stknrddr's idea: weld a strip of the .062 along the 1/2" bushing stock, and then cut the pieces.

Next, I braced things together and made sure the vertical tubes were evenly spaced, leveled up the hinge assembly with bits of metal and wire. And tacked in place. It took a lot of heat with that carriage bolt in there, so it took a while to cool.

http://rvbottomly.com/wp-content/uploads/2018/01/20180113_153858.jpg

So, one hinge done. The lower hinge is on the fuselage, so it will wait.

http://rvbottomly.com/wp-content/uploads/2018/01/hinged.jpg

I'm still having fun, and I'm still busy with dayjob work, but I'm pleased with progress so far.

I need to finish weld the whole tail group. I'm still getting by with my clunky Victor setup. I've looked over other torches in person and I probably will be ordering a Smith AW1A next week, along with a whole bunch of tubes and other stuff.

Southern Aero
01-14-2018, 11:57 AM
RV

Looks good! If you are gonna stay with the gas method you're gonna love the AW1, might save the Victor for the "big" welds. I also use threaded rod for tacking up these bushings as it doesn't absorb heat so much. But you might use a longer length instead of a shorter bolt as to include both hinge points at same time......... helps keep bushings aligned. You may already have this covered but you will need to make an 36+" or so extension for a 3/8 reamer to clean up and align each hinge point............ Ream one and then continue thru that one into the other. If you have a lathe handy it makes this easy.

Nice work. I really appreciate seeing anyone else that will build form scratch!

RVBottomly
01-14-2018, 05:18 PM
Thanks SA. Threaded rod is on my list, but I'm not doing any more hinges until I have a fuselage to line up to.

I think I'll have to order reamers, too. Nothing can be found locally as far as I can tell. I just haven't found a good source, yet.

I don't have a lathe right now, but I see myself getting one--I keep looking around. A few years back I was going to build one from the Lindsay books, but realized I'd have a better one if I could find an old one used, even with worn out ways.

Each step according to its time....

Vic

Lowrider
01-14-2018, 07:35 PM
I have a Grizzly lathe and mill...not fancy but if you take your time it will do everything you need to a 0.001".

Nice progress!!

RVBottomly
01-14-2018, 09:42 PM
Lowrider, do you have a combo mill/lathe, or two separate machines? I've been reluctant to look at those 2 in 1 machines, probably because my childhood best friend is a machinist who told me to steer clear.

But I'm not ever going to be a production shop.

Lowrider
01-14-2018, 09:54 PM
Combo.
There are advantages to both...I can turn a rifle barrel in the lathe and cut a front sight dovetail without taking it off the machine. I would say you probably get a better quality machine if you buy separate but then they are also more expensive and take up more space. I'm set up on a 5' x 8' bench with all the tools necessary and the area is "over lighted" but it's nice to have more light than you need. Grizzly is not a production machine but it will do many things well enough. With an unlimited budget I would go with higher quality and separate machines.

mike mcs repair
01-14-2018, 10:08 PM
Lowrider, do you have a combo mill/lathe, or two separate machines? I've been reluctant to look at those 2 in 1 machines, probably because my childhood best friend is a machinist who told me to steer clear.


way too much hype from real machinists... anything will get you good enough for what we need... it's not like we build rockets... just fake birds...

RVBottomly
01-14-2018, 10:15 PM
Thanks Lowrider. Good to know


way too much hype from real machinists... anything will get you good enough for what we need... it's not like we build rockets... just fake birds...

Right! I was eyeing an old set of Audi cylinder heads I have laying on a shelf thinking I could cobble together something....Maybe use the camshaft and put some kind of face plate on it, but that would be just another rabbit hole. I should probably just sell them on Ebay and use the proceeds. The poor car was totaled by a man who "didn't see the stop sign."

skywagon8a
01-15-2018, 05:56 AM
I have a Smithy similar to this one. https://smithy.com/Smithy-Combo-Lathe-Mill-Midas Yes it's small and I have also heard those stories from "real" machinists. This works just fine for me having produced lots of intricate parts for my Cub with it. It keeps me entertained for days at a time.

Lowrider
01-15-2018, 09:42 AM
Mine is very similar to Sky's machine and capable of most things that I want to do. I also have a table top Unimat lathe and mill that works very much like the bigger machine but the bed is only about 12" long will make small items very accurately as long as you don't get in a hurry.

I am NO machinist!! Totally self taught and I would never provide advice contrary to a REAL machinist but I have been successful making things I need and it seems I learn something new each time I use the thing.

skywagon8a
01-15-2018, 10:19 AM
I did learn the hard way that when machining steel you do need a cooling lubricant flowing over the bit. They don't cut very well after turning red hot. :oops: I made a lubricant squirter out of a 5 gallon plastic pail, an old hydraulic pump from a Lake LA-4, plastic tubing from ACE aircraft supply store and a gallon of 5606 (hydraulic fluid). Of course you can buy one of these but these parts were in my inventory collection.

CharlieN
01-15-2018, 10:34 AM
Tools,
I have two real Bridgeport mills and a 14" Warner Swasey lathe as well as an 18" disc sander and about 5 tons of other machines and metal forming tools.
I also have 3 Tig welders and two Mig welders as well, but I do not consider myself either a machinist nor a welder. I am a parts maker, I make allot of parts for all sorts of things.
To me tools make the job easier and generally faster. It is the person making the parts that makes them accurate.
A person with ingenuity can make most anything. A Machinist generally needs a blueprint to make a part.

Anyone want to bring up engineers? Many of these guys have a history to design stuff that is impractical to build. To me again it is those with ingenuity who get usable parts made.

Lowrider
01-15-2018, 10:40 AM
Same lesson learned with a low tech solution. I cut really slow and shallow and squirt ATF with some STP mixed in by hand and catch most of it with a specially modified Cool Whip container...it can get messy. I have had really good luck with carbide bits on steel. I still use steel bits on soft metals since they can be shaped easily with a fine grinder wheel and dressed up with a green wheel.

Lowrider
01-15-2018, 10:51 AM
Tools,
I have two real Bridgeport mills and a 14" Warner Swasey lathe as well as an 18" disc sander and about 5 tons of other machines and metal forming tools.
I also have 3 Tig welders and two Mig welders as well, but I do not consider myself either a machinist nor a welder. I am a parts maker, I make allot of parts for all sorts of things.
To me tools make the job easier and generally faster. It is the person making the parts that makes them accurate.
A person with ingenuity can make most anything. A Machinist generally needs a blueprint to make a part.

Anyone want to bring up engineers? Many of these guys have a history to design stuff that is impractical to build. To me again it is those with ingenuity who get usable parts made.

Great collection Charlie!! I'd love to have a big mill but I treated myself to on big upgrade in my new shop...a 2 post car lift...need it to work on my '58 Jeep FC 150...and other toys...maybe even airplanes.

I gotta agree with your engineer comment...and to think I had 40 hours of engineering courses before I came to my senses. I also came close to going to law school TWICE but found an MBA more useful.

Cub junkie
01-15-2018, 12:03 PM
I have a "flatbed" Atlas that was popular in the '60's. I bought it in the '80's and got a lot of tooling with it. My real machinist buddy told me at the time I got a hell of a deal and he could make it do anything but I'm still a hack. I wish I would have paid more attention to his tutoring. (He is gone now) I also have a table top mill/drill that is popular for hacks like me. It does have an R8 spindle but I haven't really done much with it except drill holes. I do fishmouth tubing on my Atlas with a vee block I made adapted to my milling vice using fine pitch roughing mills. I don't make acute angles, mostly perpendicular cuts but its nice and accurate for fuselage cross members. I don't even use lube on the cut as I don't want to clean up the oil mess. I figure a chinese mill bit from Enco for 15 bucks is collateral damage and the cost of doing business. Enough thread drift from me.

RVBottomly
01-15-2018, 12:59 PM
Enough thread drift from me.

Don't stop on my account! I'm taking all this stuff in.

I've got limited space right now, but I'm aleady scoping out a spot for an essential toy---I mean tool.


Sent from my SM-J320V using SuperCub.Org mobile app (http://r.tapatalk.com/byo?rid=93960)

CharlieN
01-15-2018, 07:33 PM
If I chose one machine to buy it would be as much of a milling machine I could get. By as much as, I mean as close to one of the full size knee mills, Bridgeport, Enco whatever.
Lathes are nice to have but the mill will do so much more such as if you need to true the ends up on bushings, clamp the bush in the collet and a tool bit in the vice. You can turn part of the OD, face an end and bore or ream the part. Then turn the part around and work the other end.
Fishmouthing tubes, use either an endmill or a hole saw in the mill. Digital protractor or the magnetic mount cube for an accurate setup if you know just what the angle needs to be or creep up to the angle bit at a time if needed. Nice thing with this method is you can easily offset the cut if the tube should not be on centerline.

jimboflying
01-21-2018, 01:11 AM
I started with hand tools, moved to a 3in1 machine, then CNC mill, CNC lathe, and then added an old Bridgeport mill. I find most of the parts that I make are made on the Bridgeport. I agree with CharlieN that they are very useful machines and used ones are not all that expensive.

Lowrider
01-21-2018, 02:03 AM
I can only dream of CNC but for production or repeatable items they are priceless. We have a company in town that rents time on their machines but you need to have your design on a thumb drive. Getting design from my head to a digital representation is a challenge for me.

CharlieN
01-21-2018, 06:16 AM
I ocasionally get frustrated on my mill when I just can not easily achieve the contours that I want and either need to simplify the part or do handwork to get the curves. I look into doing a conversion on my good machine to CNC but soon realize how much that restricts me from what I truly use the machine daily for, making simple cuts accurately. If I tighten up my older mill It would be better than just a good drillpress but I never get around to that.
But I soon have use of a new to the area CNC mill and I have some drawings I am getting ready to send to code.

CharlieN
01-21-2018, 06:28 AM
Getting design from my head to a digital representation is a challenge for me.

That is a challenging learning curve to achieve. Back in the mid 80's I took to Autocad quite easily, somehow it seemed natural for me having had proper training in Architectural drafting and my first airplanes had all been drawn on paper. 95% of what I draw now is on 20 YO ACAD software, as in that is what the plane I am currently building is drawn in.
But recently trying to get my mind up to speed in Solidworks is not happening quickly. I had started becoming proficient on Pro-E 20 years back but when that computer broke I could never got that student version running again, it needed it's one version of operating system MS NT3.5 and I never set that up again on a fresh system.
But with EAA's help Soidworks in a good system to draw on.

cubdriver2
01-21-2018, 07:51 AM
Go back to old-school Charlie

https://youtu.be/mHBanmfn_CA

Glenn

CharlieN
01-21-2018, 08:46 AM
Go back to old-school Charlie

https://youtu.be/mHBanmfn_CA

Glenn

That is a good demonstration of hand fitting tubes.

RVBottomly
01-21-2018, 11:24 AM
Go back to old-school Charlie

https://youtu.be/mHBanmfn_CA

Glenn

I just looked at a few excerpts, but I think that's pretty much how I do it so far. Except I use dividers to mark curve outer dimensions and I haven't been using a handheld grinder.

Like CharlieN mentioned, I have a bench grinder with two different dressed stones. On larger tubes, I freehand cut the profiles close with aviation shears, and then touch up with the grinder.

CharlieN
01-22-2018, 09:00 AM
I think one thing I have grown to like when fitting tubes on a mill compared to a radius dressed grinding wheel, I get to watch the cut. This allows me to back out if it looks like I set it up wrong. Tube notchers, at least the ones that use a hole saw offer this but the one I used many years back was not still enough such that the saw was prone to catching. This might or might not be an issue with the thin, small tube were are working with.
There are guillotine- shear type notchers as well but they are all but useless in my opinion.
Granted a milling machine is a major investment but for what were are working with the small mills should be fine as well as a really good vice on a serious drill press.

mike mcs repair
01-22-2018, 04:16 PM
I think one thing I have grown to like when fitting tubes on a mill compared to a radius dressed grinding wheel, I get to watch the cut. This allows me to back out if it looks like I set it up wrong. Tube notchers, at least the ones that use a hole saw offer this but the one I used many years back was not still enough such that the saw was prone to catching. This might or might not be an issue with the thin, small tube were are working with.
There are guillotine- shear type notchers as well but they are all but useless in my opinion.
Granted a milling machine is a major investment but for what were are working with the small mills should be fine as well as a really good vice on a serious drill press.

or you can use a lathe as someone on here pointed out years ago using a boring bar holder for the tube and setting angle... just be careful and not go to far and have it curl in the thin part of tube as you finish or it gets exciting quick!!

oh and one of my favorite tools for the mill, great time saver
http://www.edgetechnologyproducts.com/pro-tram-system-01-000-10-000-09-000/
http://cdn2.bigcommerce.com/n-arxsrf/1wa94vq6/products/88/images/420/pro_tram_by_edge_technology_bridgeport_milling_mac hine_angle__08115.1391121124.600.650.png?c=2

mike mcs repair
01-22-2018, 04:19 PM
you can also just use your aviation snips to cut thin .035" tube angles, very fast....

RVBottomly
01-22-2018, 04:42 PM
you can also just use your aviation snips to cut thin .035" tube angles, very fast....

I tried that a couple of weeks ago and was surprised how easy and smooth it turned out.

Right now I'm sort of on hold waiting for my big tube order to ship. I checked on the Wag Aero "fuselage kit" and they were talking 8 weeks. I sorted through all the drawings and talked with Wicks, and they are saying 1-2 weeks.

So I'm now in danger of having a touch of free time, letting me search for milling machines, etc. CharlieN, you've almost convinced me to get a decent milling machine first. But I started looking at littlemachineshop.com and might get distracted yet again.

I suppose it's a good thing that I have to pay a bunch of money for licensing fees and business taxes by the end of the month to keep me temporarily out of trouble.

mike mcs repair
01-22-2018, 05:46 PM
So I'm now in danger of having a touch of free time, letting me search for milling machines, etc. CharlieN, you've almost convinced me to get a decent milling machine first. But I started looking at littlemachineshop.com and might get distracted yet again.

you're down in the states, you should be able to find a used mill easy.... or run over to http://www.grizzly.com and pick a new one up

Cub junkie
01-22-2018, 05:47 PM
I use just about everything mentioned to get the final result. I never use one of the "joint jigger" type hole saw cutters on anything under 1" in diameter. Not a good tool investment if tube fuselages are your main project. Silver pencil and snips work good on .035 wall. I even hog out a cut on .035 with snips sometimes before finishing in my lathe. Here is a cluster that is mostly cut with snips. I have a Harbor Freight "mini" chop saw (6" wheel)that I took the guard off for manual grinding. I hand grind my silver pencil marks and I get accurate results with it.(gloves and eye protection NOT optional) Everybody has their favorites. One luxury I have for the last five years is my wireless foot pedal for my tig. Even though you still have to drag the torch around its great not dealing with a pedal cord when spending a lot of time under the hood on a fuselage.

RVBottomly
01-22-2018, 06:44 PM
you're down in the states, you should be able to find a used mill easy.... or run over to http://www.grizzly.com and pick a new one up

Right. So far I’ve found one only 2 hours away—a Simplon horizontal mill, which at $2500 is only about 50 cents a pound!
I’d have to build another wing on the shop, though. And probably rig up a 3 ton gantry to get it out of the truck.


I use just about everything mentioned to get the final result. I never use one of the "joint jigger" type hole saw cutters on anything under 1" in diameter. Not a good tool investment if tube fuselages are your main project. Silver pencil and snips work good on .035 wall.

Well, I’m glad I’m not the only one who is suspicious of a hole saw on .035 tubing. Before plunging into a joint jigger thing, I tried a straight 90 degree cut on some scrap in the drill press. It didn’t look promising. It seemed like, at best, the setup would be more tedious than just drawing lines and cutting or grinding to the lines.

I like your snipped joints. I’ll probably stick with that as the first bit of shaping.

jimboflying
01-22-2018, 10:16 PM
In the bicycle world they use tube coping calculator programs to print a paper outline template to wrap around the tube and then a marker to transfer that cut line to the tube. In the programs you enter the diameter of both tubes and the angle of intersection. You then print, cut the paper, follow the cut line with a marker, and then trim the pipe back to the cut line. An example program is http://metalgeek.com/static/cope_custom.pcgi

Gordon Misch
01-22-2018, 10:38 PM
The paper wraparound template can be created with Solidworks also, but I don't know how to do it. BTW, Solidworks is free via EAA membership.

RVBottomly
01-22-2018, 11:09 PM
In the bicycle world they use tube coping calculator programs to print a paper outline template to wrap around the tube and then a marker to transfer that cut line to the tube. In the programs you enter the diameter of both tubes and the angle of intersection. You then print, cut the paper, follow the cut line with a marker, and then trim the pipe back to the cut line. An example program is http://metalgeek.com/static/cope_custom.pcgi

Yeah, that's a pretty neat program. I've tried it out a bit. I confess to having some initial troubles printing out the outline to scale. I finally got a test 60 degree pattern cut after 10 or 15 minutes. It does leave a nice cut line.

But I'm not completely confident of my paper cutting skills. On scrap I tried out a modification of something I learned long ago, lofting boats: Use dividers to mark a few places and eyeball the curve. The key is to hold the dividers at a consistent angle.

I suppose, if I want to run an efficiency test, I could try doing 10 tubes with the printout approach, and 10 tubes with the eyeball trim and trim some more, and see what works best.


The paper wraparound template can be created with Solidworks also, but I don't know how to do it. BTW, Solidworks is free via EAA membership.

I joined EAA a couple months ago and saw that. I'm not a Luddite, but I'm sort of scared of the potential for rabbit-holing my time. That is a fascinating program!

mike mcs repair
01-23-2018, 03:47 PM
my laser printer prints different sizes, like if you do 3 separate prints or try to rerun a sheet through it might be 1/4" different size.....

RVBottomly
01-23-2018, 03:54 PM
As I wait for my fuselage materials order to come in, I started thinking about wings.

Plans call for a wood wing, but state that a PA-18 wing is suitable. I'm drawn to a wood wing after looking at Marty's work on his 2+2, but I'm also intrigued by the possibilities offered by Keller flaps.

I contacted Performance STOL and they pretty much said they don't know if the Keller flaps would be compatible with wood spars and ribs. Pretty much discouraged me from trying.

And, just to add to the mix, I have a friend who owns a commercial forest and mill. He told me he has some extremely nice 20 foot vertical grained douglas fir, no knots, straight grain, 14 rings per inch, etc. He knows I love this kind of wood and would give me first dibs for boats, airplanes, whatever.

I guess the first question is, does anyone know what the weight of a standard aluminum PA-18 spar is so I can compare it to this doug fir?

Second question, should I abandon the Keller flap idea, or go with an aluminum wing?

I'm not really asking you all to decide for me--just laying out the latest swirling thoughts.

RVBottomly
01-23-2018, 03:57 PM
my laser printer prints different sizes, like if you do 3 separate prints or try to rerun a sheet through it might be 1/4" different size.....

I ran into that, too. Somewhere I found a scale setting for my Officejet printer to match the scale shown on the screen. It always takes me a little bit to remember how to do it.

Now I remember, I ended up taking a copy of an image and putting it into a Word document, and then adjusting the scale of the image to the inches shown in the MSWord program. I made a couple templates that were accurate to 1/64". Not machinist quality, to be sure, but helpful.

skywagon8a
01-23-2018, 05:36 PM
Plans call for a wood wing, but state that a PA-18 wing is suitable. I'm drawn to a wood wing after looking at Marty's work on his 2+2, but I'm also intrigued by the possibilities offered by Keller flaps.

I contacted Performance STOL and they pretty much said they don't know if the Keller flaps would be compatible with wood spars and ribs. Pretty much discouraged me from trying.

Second question, should I abandon the Keller flap idea, or go with an aluminum wing?
Years ago I helped a friend get an STC to install flaps on his wooden spar J-3/PA-11. This was approved at the Birchwood Airport by Gordon Mandel of the Anchorage FAA engineering. I don't recall if there were any differences from the metal spar PA-18. I would suggest that as long as the spar is properly supported at each hinge location that it would be satisfactory.

If you want to get the airplane records from the FAA, I think that I may be able to find the N number. The plane has since been destroyed.

RVBottomly
01-23-2018, 05:48 PM
Years ago I helped a friend get an STC to install flaps on his wooden spar J-3/PA-11. This was approved at the Birchwood Airport by Gordon Mandel of the Anchorage FAA engineering. I don't recall if there were any differences from the metal spar PA-18. I would suggest that as long as the spar is properly supported at each hinge location that it would be satisfactory.

If you want to get the airplane records from the FAA, I think that I may be able to find the N number. The plane has since been destroyed.

Thanks for the info. The plans allow for an optional set of flaps, so I don't think you need to track down the STC info. I think the Performance STOL concern was that the Keller flaps apply more twisting force than standard flaps.

skywagon8a
01-23-2018, 05:58 PM
I think the Performance STOL concern was that the Keller flaps apply more twisting force than standard flaps.
So just beef up the area a little bit. I would do whatever is necessary to install those flaps.

Cub junkie
01-23-2018, 06:06 PM
The 2+2 plans show a picture of a flap. Thats all. If you want to see how it can be done check out how Marty did it on his wood spar. The Wag Aero prototype 2+2 was built with PA12 wings.

tempdoug
01-23-2018, 06:12 PM
if your not totaly set on making your own wings, this caught my eye.http://alaskaslist.com/1/posts/10_Transportation/59_Aircraft/488404_Dakota_Cub_Round_Tip_Wing.html

CharlieN
01-23-2018, 07:08 PM
I like wood, I like aluminum too. They both have their merits. I also see no problem with the added load of BIG flaps on the wood spar, just add the needed structure to transfer the twisting load forward to the front spar. I can understand being cautious about adding the flap loads to a factory with that is not designed for the added load, but that is not where you are at.

One note about the Keller flap design, it is optimized to replace the stock Piper flaps which do not go all the way up the the rear spar.
I would keep researching and choose a flap system that utilizes most all the space aft of the spar. If nothing else jumps out then go with the Keller system.

RVBottomly
01-23-2018, 11:39 PM
if your not totaly set on making your own wings, this caught my eye.http://alaskaslist.com/1/posts/10_Transportation/59_Aircraft/488404_Dakota_Cub_Round_Tip_Wing.html


Tempting for sure. But I think I'll press on.



I like wood, I like aluminum too. They both have their merits. I also see no problem with the added load of BIG flaps on the wood spar, just add the needed structure to transfer the twisting load forward to the front spar. I can understand being cautious about adding the flap loads to a factory with that is not designed for the added load, but that is not where you are at.

One note about the Keller flap design, it is optimized to replace the stock Piper flaps which do not go all the way up the the rear spar.
I would keep researching and choose a flap system that utilizes most all the space aft of the spar. If nothing else jumps out then go with the Keller system.

Well, that sets the wheels turning. I guess I'm going to dig in a bit more on flap design and wing "beefing up."

One idea I've seen is to have compression members bracing top and bottom of spars instead of just the middle.

CharlieN
01-24-2018, 04:10 AM
Well, that sets the wheels turning. I guess I'm going to dig in a bit more on flap design and wing "beefing up."

One idea I've seen is to have compression members bracing top and bottom of spars instead of just the middle.

Correct, similar to the N brace at the lift struts but primarily you need to transfer the upper and lower flap attachment loads forward to the front spar. If the flap has a greater cord the mounting loads are actually reduced at the spar since they have a shorter moment arm back from the structure. Higher loads yet less moment arm.

A year ago my project was to use a wood structured wing. I was going to use Vee braces to carry to control loads forward though the structure. I have evolved from there to achieve my design goal but am still not fully locked down on details yet. I do not need to be yet.

You are scratch building so you are open to many options to achieve your desired goals. As with me on my project, you are building the fuselage structure first. This is very good since once the main fuselage is built there is still a massive amount to do to build out the systems prior to covering.
It is during the main structural work on the fuselage that you do your final design and planning for the wings. There is no need to be stuck with what was provided 70+ years ago when you can benefit from the decades of what has been learned since.

Gordon Misch
01-25-2018, 04:34 AM
primarily you need to transfer the upper and lower flap attachment loads forward to the front spar.

I think triangulation, like with the N-strut you mentioned or another method such as with the ribs, also matters in order to prevent twisting the spars.

Southern Aero
01-26-2018, 12:33 AM
RV

FWIW, if you look at Pipers design flaps and aileron hinge points are mounted to the spars but fairly lightly. The "false spars" are closest to the hinge points and carry most of the loads thru the false spars into the ribs...... that spreads the loads. If there were no false spars there would be greater need to stabilize the spars.

RVBottomly
02-06-2018, 10:24 PM
So I finally got my fuselage materials. Had the 24 foot long box delivered to the local depot to save shipping costs.

But the driver called me and said I ought to check it over for damage:

35087

I talked to Wicks and was told to accept and inventory the damage. They'll make it right. Happily, when I got it home, I found only 1 six foot section of 1" X .035 and 3 six foot channels damaged beyond usability. Everything else looks sound.

I've got my jig table set up and a bunch of steel. The only thing I don't have at the moment is time. But I hope to be scratching some of that up shortly.

CharlieN
02-07-2018, 06:15 AM
Damage sucks, luckily they are just shorts which are easy to ship the replacements.

RVBottomly
02-11-2018, 10:56 AM
Yesterday I had a pleasant enough time cutting up tubes, profiling ends by grinder, file, and snips, and laying things out for the upper section of the fuselage.

Of course, once it was there, I had to tack it. I love the new Smith AW1A torch, but didn't think to take pictures of it.

http://rvbottomly.com/wp-content/uploads/2018/02/20180210_163937948550406.jpg

Over on CharlieN's thread I mentioned the Vagabond. The responses there almost had me switching to building a Wagabond (I have the plans in the shop). I was thinking of lengthening it and putting on bigger wings, etc.

Then I remembered I went through all this before. I'm sticking with the original plan unless I get persuasively derailed. I'm looking forward to fitting the lower fuselage section together this week and then jigging the frame for joining. It really is nice to spend some time just working with material.

CharlieN
02-11-2018, 01:05 PM
It's a good feeling when each sub-assembly comes together.

My gas rig that has been my mainstay has been a Purox 200 which I believe is the same size torch your Smith's is. Great size to work with.
If you get tired fingers or hand cramps you might consider some friction tape or similar on the body of the torch so it will stay in your hand without gripping it. This will allow more finesse while working.

My father gave me the Purox torch I have back in the late '60s, it was a used hand me down and has seen allot of use over the decades. That was the first "real" tool I had.

Dave Calkins
02-11-2018, 04:09 PM
RV. save the Doug Fir for your boating hobby. Weight of it will be more than the aircraft standard Sitka Spruce.

As to transferring flap loads to the tear spar and beyond. Doubling the ribs at the flap hangers or making a truss rib with an additional plywood web will transfer the loads to the front spar an ameliorate rear spar twisting more elegantly than doubling compression members or having "N" struts.

imho

RVBottomly
02-11-2018, 05:09 PM
RV. save the Doug Fir for your boating hobby. Weight of it will be more than the aircraft standard Sitka Spruce.

As to transferring flap loads to the tear spar and beyond. Doubling the ribs at the flap hangers or making a truss rib with an additional plywood web will transfer the loads to the front spar an ameliorate rear spar twisting more elegantly than doubling compression members or having "N" struts.

imho

Good points. I did check out the fir more closely. It's really solid, hard, old-growth stuff from the Blue Mountains of WA/OR. Really tight rings and really dense. I weighed a rough cut 2X6X16 and it came out to 48 pounds or so. That's more than 36 pounds per cubic feet. In boatbuilding we always rule-of-thumbed doug fir at 34 pounds/cu ft. Just now I see them using 32-33 pounds, but that must be the lighter new-growth stuff.

I'm pretty much sold on some kind of truss rib instead of additional compression members. Mike MCS mentioned something like that in an older thread and that started the gears moving.

RVBottomly
02-11-2018, 05:10 PM
My gas rig that has been my mainstay has been a Purox 200 which I believe is the same size torch your Smith's is. Great size to work with.
If you get tired fingers or hand cramps you might consider some friction tape or similar on the body of the torch so it will stay in your hand without gripping it. This will allow more finesse while working.


My father gave me the Purox torch I have back in the late '60s, it was a used hand me down and has seen allot of use over the decades. That was the first "real" tool I had.


I passed on a Purox torch in an auction 2 decades ago because I didn't know anything about them. I think it was a "Presto" model. I now wish I had grabbed it.


So far the grip feels pretty nice. I don't grip it very hard. The next improvement will be to get some lightweight hoses.

Gordon Misch
02-12-2018, 12:53 AM
I'm pretty much sold on some kind of truss rib instead of additional compression members.

Yes. You'll be resisting moments with the truss rather than torsional stiffness of the spars.

RVBottomly
02-19-2018, 09:49 PM
Another week, and most of that week was spent doodling and planning. I spent a lot of time laying out the jig for the lower fuselage frame. I didn't like how the plans depicted the jig.


The lower fuselage bends up at the rear gear attach point. The jig drawing is set up to more or less accomodate it, but I wanted a precise X-Y-Z coordinate for each station. That is not in any one place on the plans.


Bouncing among various drawings, I was able to finally locate all the points I wanted. It turns out that the plans for the jig look to be fairly accurate, but I wanted to see for myself.


Last Friday, I visited the new Harbor Freight that opened in Lewiston, ID, last month. Before that, the nearest one was 135 miles north. I saw an "open-box-scratch-and dent" mini-lathe for $350. I looked it over and it followed me home. I actually had been scouring the local Craigslist for something I could use to turn down liner tubes. This ended up being a decent enough solution.


http://rvbottomly.com/wp-content/uploads/2018/02/20180217_1616001279210822.jpg


On the lower fuselage frame, there are two splices at the gear attach points, just as there are on the super cub. The plans have 3/4" .035 longerons joined by 5/8" liner tubes. I didn't like that much gap--the longerons' ID is around .680 and the 5/8 OD is, of course, .625. The standards apparently allow that much gap with several rosette welds, but I wanted tighter. I had ordered a length of 11/16 X .090 from Univair and had it ready. It just needed to be made a little smaller.


http://rvbottomly.com/wp-content/uploads/2018/02/20180219_134124.jpg


http://rvbottomly.com/wp-content/uploads/2018/02/20180217_1615441073715542.jpg


My first try on the lathe was a little rough. After shimming the tool height and getting familiar with its operation, I ended up with some decent pieces.


Prebent the liners and dry-fitted joints.


http://rvbottomly.com/wp-content/uploads/2018/02/20180219_143401.jpg

(http://rvbottomly.com/wp-content/uploads/2018/02/20180219_143342.jpg)http://rvbottomly.com/wp-content/uploads/2018/02/20180219_143342.jpg


Then I started tacking tubes.

http://rvbottomly.com/wp-content/uploads/2018/02/20180219_155136980522897.jpg

(http://rvbottomly.com/wp-content/uploads/2018/02/20180219_155152.jpg)http://rvbottomly.com/wp-content/uploads/2018/02/20180219_155152.jpg


I mentioned doodling and planning. I've spent a surprising amount of time reading aerodynamic books and articles. The focus has been trying to calculate flap and aileron forces on a spar, of all things. So far, I think I have a handle on it using the drag and lift equations and estimating various coefficients. I'm surprised there doesn't seem to be a lot of information on such things. I know people put big slotted flaps and move ailerons outboard, but I've never actually seen any calculations to support it. I'm sort of obsessed with seeing the numbers.

Anyway, another thrill-filled day and a half in the shop. A cold front and strong winds kept outdoor activity at a minimum--and made me appreciate the heater I put in the shop last year. Plugging along.

RVBottomly
02-24-2018, 09:39 PM
Small update. I'm closing in on tacking up the lower section of the fuselage.

http://rvbottomly.com/wp-content/uploads/2018/02/20180224_144853507738580.jpg

I picked up a laser level before putting in the heavier tubes in the front. I was surprised at how square things remained. One of the issues I had is my floor settled slightly a year after it was poured. There is a fairly consistent 1/4" in 10 feet slope in one of the quarters of the floor. I tried to account for that with shims under those 1X4s. Even with my table on casters, it remains true when I put it in the same spot.

The other thing I learned today is not to let your Harbor Freight lathe's lead screw run to the end of its travel on its own. Instead of it running out of thread, it reaches a stop, and the drive screw seizes.

It was not a hard fix, what with plastic gears. I was able to take off the gears and back it off. The plastic gear had its key-way stripped, but it was still a fairly snug fit. I was able to cut another key-way with a small wood chisel. It now works just like it did before. Live and learn. I was used to an Atlas lathe from long ago that had a little interrupter on the half-nut to disengage it.

I've got one question for now: Is it OK to heat bend .090 sheet 4130? So far my attempts at a homemade press brake are falling short.

Cub junkie
02-24-2018, 09:52 PM
You can heat bend .090 but don't allow any air movement while your material cools. Don't even walk by while it cools. Piper didn't use 4130 for their heavy brackets in the 40's.

RVBottomly
02-24-2018, 10:05 PM
You can heat bend .090 but don't allow any air movement while your material cools. Don't even walk by while it cools. Piper didn't use 4130 for their heavy brackets in the 40's.

I saw someone mention covering it with fiberglass insulation before it cools. Would that be a good idea?

Gordon Misch
02-24-2018, 10:25 PM
Covering it with fiberglass will reduce it's mechanical properties. It wiil tend toward being annealed. You want normalized, which is cooled in still air. I'm assuming it is normalized sheet, which would be marked as condition "N".

RVBottomly
02-24-2018, 10:32 PM
Covering it with fiberglass will reduce it's mechanical properties. It wiil tend toward being annealed. You want normalized, which is cooled in still air. I'm assuming it is normalized sheet, which would be marked as condition "N".

That's what it is. Thanks for the head's up.

Cub junkie
02-24-2018, 10:39 PM
I've made Piper replica fittings with heat bend. I've also made redneck style press dies and bent the .090 cold. Had equal success with each. Too late for you but anybody building a Wag aero airplane would be way ahead buying their fuselage material kit. They supply all those hard to make fittings ready to weld on. Its actually a real good buy considering.

RVBottomly
02-24-2018, 10:51 PM
I've made Piper replica fittings with heat bend. I've also made redneck style press dies and bent the .090 cold. Had equal success with each. Too late for you but anybody building a Wag aero airplane would be way ahead buying their fuselage material kit. They supply all those hard to make fittings ready to weld on. Its actually a real good buy considering.

Right, too late for me--except that they told me it would be two-three months to get it. That was a month ago and I was impatient!

RVBottomly
03-17-2018, 06:59 PM
A few weeks went by, and I had more therapy than apparent progress. But I was plodding along.

The main time-consumer was getting the top and bottom assemblies lined up. As far as I could tell, the jig dimensions on the plans would not do it. The dimensions would place the upper assembly askew compared to the frame drawing referencing a datum line.

So, I abandoned the pre-fabbed jig approach, ran a datum reference string fore and aft, and shored up the frame piece by piece. It ended up being sort of tedious.

http://rvbottomly.com/wp-content/uploads/2018/03/20180303_161336418344132.jpg

Every adjustment changed something else. I'd take a break, come back, fiddle with it again, and finally got everything aligned pretty close to the specs.

Today I tacked a few tubes:

http://rvbottomly.com/wp-content/uploads/2018/03/tube-fwd.jpg

http://rvbottomly.com/wp-content/uploads/2018/03/2018.03.17-tube.jpg

In the mean time, I had a side project. The $350 scratch-and-dent 7X10 mini lathe from Harbor Freight is now a 7X16 mini- lathe.

As it was:

http://rvbottomly.com/wp-content/uploads/2018/02/20180217_1616001279210822.jpg

As it is now:

http://rvbottomly.com/wp-content/uploads/2018/03/20180317_154949.jpg

The extension kit came from Little Machine Shop and added $180 to the machine. It took several hours to put it together, but now I can turn down some of those 11/16 liner tubes in the rear fuselage frame.

CharlieN
03-17-2018, 08:00 PM
Here I am sitting at the end of the day with a smirk on my face and a little bit of a chuckle. Thinking back to how many times a structure just will not take a set, it can get frustrating, angering at times. Then all of a sudden, it is just right. But I am too damn worn out to start fitting tubes and weld. Will it still be in alignment in the morning.
But when it is right, it is just that, it is right and that is such a damn good feeling. It is so nice to be moving along.

Nice find on the lathe, Out of curiosity what diameter tube will pass through the headstock and chuck?

RVBottomly
03-17-2018, 08:15 PM
Here I am sitting at the end of the day with a smirk on my face and a little bit of a chuckle. Thinking back to how many times a structure just will not take a set, it can get frustrating, angering at times. Then all of a sudden, it is just right. But I am too damn worn out to start fitting tubes and weld. Will it still be in alignment in the morning.
But when it is right, it is just that, it is right and that is such a damn good feeling. It is so nice to be moving along.

Nice find on the lathe, Out of curiosity what diameter tube will pass through the headstock and chuck?

Right now the limiting size is the chuck. 5/8 passes through, but 11/16 does not. If you take the chuck off, there is .80 inch diameter clearance. I'd think I could bore the chuck enough to pass a 3/4 tube easily.

Vic

Cub junkie
03-17-2018, 08:29 PM
I have never liked how the jig is depicted on the wag aero plans for the 2+2. I got lucky when I helped build a 2+2 fuselage. I had a bare PA12 sitting net to my jig work off of. I set the PA12 on the jig table and built the jig to the bottom of the PA12. Then it was easy to build the wider top, affix it in place and fill in. I'm a crap carpenter and I felt like there was too much carpenter work involved with the wag aero jig. Glad to see your progress.

RVBottomly
03-17-2018, 10:46 PM
I have never liked how the jig is depicted on the wag aero plans for the 2+2. I got lucky when I helped build a 2+2 fuselage. I had a bare PA12 sitting net to my jig work off of. I set the PA12 on the jig table and built the jig to the bottom of the PA12. Then it was easy to build the wider top, affix it in place and fill in. I'm a crap carpenter and I felt like there was too much carpenter work involved with the wag aero jig. Glad to see your progress.

A spare PA 12 would have been nice to have. That sounds like a good way to get it done.

I'm quite used to working in wood, but in this case I think the dimensions are wrong. For instance, a jig is laid out for a certain height and set a certain number of inches from a station. Cut a 3/4 notch for the longerons, and you end up with a longeron a couple of inches out of position in reference to the datum line. I couldn't make it work, even assuming for logical typos.

I remember reading Marty's website how he mentioned some problem with the jig so he worked around it. I think everyone has to do it, apparently.

But that's the fun of scratch building. I ran into the same sort of thing on the last dory I built, too.

CharlieN
03-18-2018, 05:09 AM
Right now the limiting size is the chuck. 5/8 passes through, but 11/16 does not. If you take the chuck off, there is .80 inch diameter clearance. I'd think I could bore the chuck enough to pass a 3/4 tube easily.

Vic
As long as the jaws have the travel you should be able to use a boring bar and open the body of the chuck up to the .80, Take a look at the backside of the chuck, you might consider splitting the body and look at the scroll to make sure there is room for the cut, I expect there is but best to check. Bad enough to scrap material but aggravating when one scraps tools.
That was you can work longer pieces with stability.

CharlieN
03-18-2018, 05:24 AM
That sounds very frustrating about the plans being off, hopefully it is just an error in the tooling and not so much in the structure.
I just got to realizing I have some Wag plans here that I purchased back in the '80s that I never worked with. Truly forgot I have them.
One would think the errors would have been corrected by now.
I have worked with a number of Rutan influenced planes, Quickies and and EZs and such and when you find a template for cutting out the foam wings is wrong it is really aggravating to find how much scrap you have from errors that should never have made it to print. That was one of the big drives for me to draw all my own projects be it to redraw an airfoil if not just to see if the shape I draw from the ordinates is the same as they drew. Many times it is not as was the case for the plans we had from the later '70s era.
Those problems should not have made it to print and truly should not still be in print 30-40 years later.

RVBottomly
04-07-2018, 09:28 PM
So I started this thread high on hope I'd find maybe 20 hrs a week. Past 3 weeks I've gotten 7 hours in. Best laid plans; surprise twists and turns in my caseloads, etc.

But, reporting now just bit more progress.

I finally lined up the tailpost and confirmed the fuselage was square overall before tacking it.

http://rvbottomly.com/wp-content/uploads/2018/04/20180407_140754473973110.jpg

BTW, I do have a good quality level in addition to that Harbor Freight one in the picture. But that came with a laser function, which was fun to play with for a while, before I went back to strings for a datum.

I wanted to see how things fit with the stabilizer:

http://rvbottomly.com/wp-content/uploads/2018/04/20180407_141326.jpg

I turned out that the tail post angle is slightly off. Everything back there is still tweakable as it is only lightly tacked.

Slow, but perceptible progress:

http://rvbottomly.com/wp-content/uploads/2018/04/20180407_151732.jpg

I keep telling myself, "I just need to get through this month...and then...."

Heh. Still having fun, though.

jimboflying
04-08-2018, 08:55 AM
Did you remember to put doublers in the longerons in front of the tailpost?

RVBottomly
04-08-2018, 09:47 AM
Did you remember to put doublers in the longerons in front of the tailpost?

Err, Umm. Funny you should mention that.

Before I saw your post, I walked out to the shop to get some chicken feed and I looked on the table by my lathe. Lying there were the two doublers I turned down from 11/16 tubing 3 weeks ago, waiting for installation....

Good thing those tail post tacks are light.

Of course, the doublers are not shown on the Wag Aero plans, and I had forgotten to note them on the plans.

Two steps forward, etc.

Thanks for keeping an eye on me, Jimbo.

Cub junkie
04-09-2018, 08:06 AM
You planning on the "H" or "X" brace in the bay in front of the tail post?

RVBottomly
04-09-2018, 08:16 AM
You planning on the "H" or "X" brace in the bay in front of the tail post?

I'm still trying to figure out what the differences are. I'll use one of them, probably. X intuitively seems better, but I need to read up on them more.

Another place that looks like it could use bracing is at the stabilizer attachment on the upper longeron. It sits mid span. I've seen references to the longeron being bent there.

Cub junkie
04-09-2018, 08:42 AM
I like the X. Easy to do.

CharlieN
04-09-2018, 09:34 AM
I would build the X simply because it is structurally better.
And I would brace the stab mount area as well, does not need much, maybe a 5/8x.028 or .035 on each side.

RVBottomly
04-28-2018, 06:53 PM
Up for air after a couple of weeks. I reached something of a milestone, now having the main fuselage mostly tacked together. There are still a few tubes to put in, but the shape is there. It measures square and pretty close to the numbers on the drawing.

I weighed the assembly using a moment arm technique I worked up for boat building. No pictures, but the basic idea is to find the center of balance, and then put a fulcrum 10 inches one way or the other from the center of balance. Then go to the up end and add weights at a certain distance. Then calculate the moments. I did it both ends and came up with 54.4 pounds each way.

Seeing it was pretty light, I hung it from a rafter and weighed it with a fish scale. It came out to 54.7 with that method, but that included the ropes tied to the frame to hang it from.

http://rvbottomly.com/wp-content/uploads/2018/04/20180428_155116.jpg

Then I rolled the jig table outside.

http://rvbottomly.com/wp-content/uploads/2018/04/20180428_160638.jpg

http://rvbottomly.com/wp-content/uploads/2018/04/20180428_160848.jpg

The main point to all this moving was to get the assembly lower for work on the superstructure. I hope to build a rotisserie from scraps in the near future.

Lowrider
04-28-2018, 07:35 PM
Looks like progress to me!!

I used 2 V-8 engine stands for the fuselage turn around thingy and they worked really well for welding and painting...just a thought.

RVBottomly
04-28-2018, 10:24 PM
Looks like progress to me!!

I used 2 V-8 engine stands for the fuselage turn around thingy and they worked really well for welding and painting...just a thought.

I've seen something like that, but I don't have any engine stands.

But what I do have is an extra 22' piece of 7/8" tubing. Seems like that would make fairly decent axle spit with some homemade bushings from leftover 1" tubing.

CharlieN
04-29-2018, 05:10 AM
The rotisserie is easy enough to make from wood. A dolly for the base, say 2X3', a braced vertical 2X4 tall enough to allow full swing of the finished structure. At the firewall, it is nice if the pivot point can be changed as the balance of the structure changes such that a piece of plywood bolted to the engine mounts might be right, but just a board across the upper two and the lower two engine mount point with a vertical board with the pivot points drilled in.
Tail post end can be hose clamped to a bit of angle that has the pivot tube welded to it.

An issue with most engine stands is their pivot tubes are not level to the ground, they are always twisting about when spinning the structure. This does not allow for stability which is our safety. There is no way I want something to start rolling over when I am half inside the structure leaning on it as I weld.

I do have a heavy duty rotisserie that I built decades ago for building cars and boats, this is a recent BMW build on the spit.
36731

And a different one getting the interior painted last summer,
36732

Rolling a ton of car is a one man task when balanced right and a 100# fuselage can be safe and simple.

Cub junkie
04-29-2018, 09:50 AM
I use ho' made U joints at each end. I was going to use old car U joints but they are bulky and usually greasy. I made up a couple of U joints from floor sweepings. You can cobble anything in framework to work off old saw horses etc. or some type of similar stands. The Harbor Freight cheap auto engine stands with the ubiquitous 20% off coupon are affordable and I never feel guilty chopping on HF stuff, it usually needs it anyway.

RVBottomly
05-19-2018, 09:27 PM
Wow, three weeks since last update. That's mainly because I had little to show. But I spent a fair amount of time with a tape measure, plumb bob, homemade trammels, etc., tracking down annoying discrepancies.

I was working on the superstructure and I had the hardest time getting things square. I built a scaffold and measured everything against the datum line. Tacked up some tubes in a perfect square (according to the template), only to find it out of square when I mounted it on the scaffold.

Heh. CharleyN and Marty said there'd be days like this. I had about 6 (partial) of them--tacking and then going back and grinding away tacks--measuring, fitting, rejecting, re-profiling, clamping, measuring, etc. On and on. Finally it came together. The only way I could really line things up was to fasten a swiveling wire on the tail post and measure everything from there.

So, finally a step forward:

http://rvbottomly.com/wp-content/uploads/2018/05/20180519_185409.jpg

http://rvbottomly.com/wp-content/uploads/2018/05/20180519_1854541802498408.jpg

It's still pleasant therapy for me, despite the back-eddies. My great plans at freeing more time got derailed by a bunch of new cases assigned to me. On the upside, it looks like I'll hit my court-mandated limit in August instead of next January. Maybe that will free up some time.

CharlieN
05-20-2018, 04:19 AM
I am happy I bench made my cabin top since it is square. I have since welded too it and it has yet to move and with the X brace it may well have some pent up loads in it but it remains accurate.
With it being square this reduces your workload when getting it in place on the rest of the fuselage.
Basically you are not trying to keep it square as well as level and lined up all at the same time.