Tube bending

[CBoyer]

Yesterday was my first attempt at bending the leading edge of the horizontal. I don't have any dies, so I just tried the bench method. The bend ended up very uneven, not planar, and had a few kinks. Needless to say it now lives in the scrap bucket. Harbor freight only has one tube bender that remotely resembles what is shown in Eric's manual, but it only has two dies (7/8" and 1/2"). My question is: are these two dies sufficient to the the 3/8" and 5/8" tubing without squishing/oval-ing the tube too much? My guess is anything would be better than the bench method.

Or, how can I go about making wooden dies? Find someone with a wood lathe?

Thanks,
Casey Boyer
BH1308

[marcusofcotton]

Not speaking from experience here, perhaps ease it around with a 3/4" EMT conduit bender???

Mark J

[nuggets]

I made the 6" radius wooden quadrant block method in the bearhawk book and just used a wood rasp to make a recess for the tube ,worked fine -just a little at a time as its easy to over bend

[alaskabearhawk]

Here's what I did:

http://www.mykitlog.com/users/display_log.php?user=yeeeha&project=527&category=7248&log=144020&row=125

[wingnut13]

Yep, stay away from the HF tubing squishers for this project. They don't make nice bends in tubing that needs to retain it's strength.

[alaskabearhawk]

Here's what I used for the smaller tubing and it worked remarkably well. If you have access to a router, you can make something similar out of oak:

http://www.mykitlog.com/users/display_log.php?user=yeeeha&project=527&category=7248&log=159831&row=100

[CBoyer]

The harbor freight one i was thinking of is basically an emt conduit bender, but can be disassembled and the dies bolted to the work bench. I was just wondering if an oversized die would oval the tube (bending a 5/8 tube over a 7/8 die). I can use a router to make the dies i need. For some reason the router slipped my mind. Thanks, Casey Sent from mobile

[alaskabearhawk]

You definitely need the proper cove for the tube diameter to keep it from deforming. The deeper the better, but get as close as at least half the diameter of the tube. More if possible.

[Bearhawk535]

This is what I used to bend the horizontal stab tubing. Built a smaller one for the trailing edge of elevators. The shape and general idea is from one of the Bengelis's books. I used two halfs of 3/4 plywood and routed half of the groove on each half then glued/screwed them together. I then drilled holed to attach to the leg of one of my EAA/Chap 2000 work tables with bolts and wing nuts. Worked very well and I got both bent to within a 1/16th of each other in about an hour. I used the heaviest piece of 3/4 tube stuck in the end about 3 inches to give me a little more leverage to make the bends near the end of the tube. I am not sure why the photos rotated 90 degrees in the upload. Hope someone finds this helpful

[wingnut13]

Nice work on that bender! And now I have another project to add to my list.

[CBoyer]

Yes, thank you! I've seen that in the yellow book. Did you basically make the same shape in the book? Is there any science to it's shape that you know of? I'm saving for a router and will get to one of these soon after. Thanks, Casey

[Bearhawk535]

I don't know if there is any science in the shape, but it gives you a wide range of bend radii that allows you to bend a lot of different shapes. I found that I could do a pretty good job of getting a constant radius by pressing down to a certain point move a little and repeat along the curve.