Author Topic: Making a round tail  (Read 691 times)

wbpace

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Making a round tail
« on: Oct 24, 2017 »
I really like the looks of the round tail, so that's what I am making.  My problem is getting a nice curve.  I got most of the bend by pulling the tube around the forming template (as described in the instructions book that came with the plans), but the tube's springback gets me nowhere close to the final shape.  So my question, to anyone who has built a round tail, is how did you get a nice curve to bring it the rest of the way?

Tony Bingelis describes several bending jigs. Most seem to be more appropriate to making a more acute angle, but one possibility is to take a pulley wheel (sheave) and running back and forth over it while pulling to increase the curve.  Are there other, better techniques?

O'Bill

Smokyray

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Re: Making a round tail
« Reply #1 on: Oct 24, 2017 »
OB,
You might try heating the tubing before bending it, if you haven't already.

Attached is a Sonerai for sale U-tube video that shows a bit of detail at the end how he "bent" the tail.
His contact info is on the video...
FYI
V/R
Smokey

https://www.youtube.com/watch?v=4OD95B4pXzo


dcstrng

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Re: Making a round tail
« Reply #2 on: Oct 25, 2017 »
When I was bending mine (project now sold), I bent it through the crotch of a tree out back – yes really. ???  Would bend just a bit, check against the template, bend some more until it fit the paper pattern…  Read about doing that somewhere and was surprised how fair the curve was, but I was timid and took my time…  I’d loan out the tree, but it came down in a thunderstorm a couple of summers back.

I might add -- I built(rebuilt) my VT three times before i was happy with it, but not because of the curve...
« Last Edit: Oct 25, 2017 by dcstrng »
-- Larry

wbpace

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Re: Making a round tail
« Reply #3 on: Oct 27, 2017 »
Thanks, guys.  I don't have any big trees, but I'll find something like that.  I started with the horizontal stabilizer, which I presume will be the most difficult because it uses the largest tube (5/8") that needs to be bent.

But that video! Thanks for posting it Smokey. I absolutely LOVE those brakes and was wondering where I can get drawings or measurements for those Pitts-style  pedals.   And I was also taken by the simplicity of his panel, which makes the location of the radio really work.  Some real thought went into that rebuild, so Matt Meyer, if you are reading this, please post some pictures of your airplane before you sell it.

O'Bill

Mytonic

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Re: Making a round tail
« Reply #4 on: Oct 27, 2017 »
I believe 1/2 tubing is the largest to bend
« Last Edit: Oct 27, 2017 by Mytonic »

wbpace

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Re: Making a round tail
« Reply #5 on: Oct 27, 2017 »
Sorry, you're right.  Chalk that up to trying post late in the night.

O'Bill

Maxdriver

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Re: Making a round tail
« Reply #6 on: Nov 07, 2017 »
When bending using heat, like on the canopy frame bows, you'll know right away when its hot enough. hold some tension on the tube while someone else heats it. That way you can feel it and make the bend. That round tail is nice and I'm sure it will be worth your effort.
Dennis Tyson
Sonerai IIL Stretch

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Re: Making a round tail
« Reply #7 on: Nov 08, 2017 »
Hi Max, glad to see you back!

I was able to bend them much of the way pulling them around the pressboard templates.  Of course with springback, they were nowhere near to close, but this only took a few minutes and got things going in the right direction.   Then I got a 4-inch sheave/pulley from Harbor Freight for about 12 bucks, clamped that in my vise, and started working the pieces back and forth over it get the entire curve, going back and forth between tool and template.  Kinda like working on a French Wheel.  Where it is really turns in near the outboard tip, I would sometimes work only a very few inches at a time.

I didn't use heat.  Tony Bingelis insists bending be done cold as uneven heating will lead to uneven bending.  I filtered some sand I had to get the junk out, and packed it into the tubes.  The ends were sealed with some plastic bits and superglue. Then I just slowly worked it until I was happy.  The tubes were flattened no more than 1/256" at even the most acute bend areas.  I can strongly recommend this technique.

Well, I did use heat just once, and that was in a tiny area to take out some twist out after bending was done.

But it wasn't fast.  It took me about a day and a half to dial in all four elevator and horizontal stab edges.  I'll post pictures once the welding is all done.

O'Bill

 

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