Wag Aero — taper flattening stabilizer leading edge ends

[rv7pilot]

I am building the balanced tail group for a Sport Trainer, and learned that the leading edge (1” tube) needs to taper/flatten down to create a smoother transition to the balanced elevators. Any advice on how to do this smooth, even taper/flattening? A vise seems like it may be a bit too localized for a good taper, but maybe it is the squeeze, move, squeeze, move, etc method?

Thanks!

 

[skywagon8a]

I am building the balanced tail group for a Sport Trainer, and learned that the leading edge (1” tube) needs to taper/flatten down to create a smoother transition to the balanced elevators. Any advice on how to do this smooth, even taper/flattening? A vise seems like it may be a bit too localized for a good taper, but maybe it is the squeeze, move, squeeze, move, etc method?

Thanks!

Heat it with your torch and tap it to shape with a hammer. Be sure to tap the bottom as well as the top for symmetry.

 

[CharlieN]

Not knowing what your resources are a press would be easier than a vice but the vice is fine if that is what you have. Hopefully it is a pretty big one since you need some power.

Get yourself two pieces of soft 1X boards, pine, spruce, fir anything like that. Foot longish, not critical. Having a helper is of great value for this since it will get unwieldy.

You need to hold the end of tube between the two pieces of wood in the vice. As you squeeze on the tube the wood on the open end of the tube should be allowed to squeeze together while the tube itself resists compression. You may or will want a spacer to control the closed end dimension as the tube is formed into an oval so as to not go thinner than needed. If the tube is deforming into a figure 8, control that by whittling a bit of wood to insert into the tube to support the center from over compressing.

It will probably take more than one go at this to get the length of taper you desire but the key is the wood will not leave tool marks nor steps in the worked area.

A challenge may be making a symmetrical taper. It can be done with top quality results with simple tools.

FWIW Decades ago I have set up wood blocks and tubing and driven over it with a truck, worked well but I sure like having better tools now.

 

[Cub junkie]

I use a wood working vise with the wider jaws of hardwood. I don't think I have a pic of doing it but it worked good as I was able to hold the tube in one hand and position it while I squeeze. I'll look for a pic. Easier to do than describe.

 

[rv7pilot]

Great advice, and exactly what was needed! I’ll give the vise/blocks a shot in some scrap to fine tune things and see how it goes. Thanks!!!

 

[rv7pilot]

Hilarious! Can just imagine using my car to form parts, but hey — what works, works! Glad to hear that I am likely overthinking the work. Thanks!

 

[Cub junkie]

Great advice, and exactly what was needed! I’ll give the vise/blocks a shot in some scrap to fine tune things and see how it goes. Thanks!!!

Your initial post has it down in my opinion. squeeze, move ,squeeze. rinse,repeat. I remember using some tapered door jam shims from the box store to assist in the cause as they would lay in my wood workers vise without an extra pair of hands or attaching them to anything. Lot of moving back and forth and of course keeping the stab. tube in the proper plane with the taper.

 

[CharlieN]

Hilarious! Can just imagine using my car to form parts, but hey — what works, works! Glad to hear that I am likely overthinking the work. Thanks!

Today's cars aren't heavy enough any more compared to the V8 stuff many of us grew up in.
Actually many of them are heavier than the late '60s cars.

I can just see someone out in their driveway this day and age with piles of wood with sheet metal in it and using a car as the press tool to form a part. I bet I do have some old slide film pics of when I was doing just that way way back. Got to make do with what you have to get your job done.

 

[mike mcs repair]

not directly to your question, but I know when the one company up here initially started making them, you leave front tube long and bend both stabilizers on same tube around the same wood form