Wow, thanks for the replies!
Originally Posted by mania
pipe is cheaper than tubing. maybe you could buy a pipe sized die. if you use 1.66 OD your frame will be NRS compatible and if you use 1.9 OD your frame would be DRE compatible. this would be a possible selling point or if you were in a pinch for a spare part.
I thought about this, but changed my mind when I checked pricing...$300 for a set of dies. Quite a bit more than when I bought the machine years ago.
........more than likely you will create stress fractures when you bend aluminum of that hardness.
Very good point, and this hadn't crossed my mind. I am guessing that this is a good reason to scrap this approach. Very likely the cracks wouldn't be visable until it was too late. Thanks for mentioning this. When I found the commercially available 6061-T6 elbows, I just assumed it would be possible to bend the material myself...It didn't occur to me that they were bending them in the "O" condition and then heat treating them.
I am an A&P also. I worked in General Aviation up to about 6 years ago, haven't used the license since, sometimes I miss being around the airplanes though.....
If you are set on bending the corners then you need to go with a 5000 series tubing. I use the T6061 and speed rail fitting that you can get at Aviation Industrial Supply in Denver. Just make sure that you get you coolers and boxes first so you can build the frame around them. A chop saw with a fine tooth wood blade work well to cut the tubing. Wear Eye Protection. Good Luck
Maybe I should change this to a "How should I build my frame?" thread.
I had read up on the speed rail fittings, and while they offer great flexibility it seems that they are just not as secure as a welded frame would be. That being said, obviously several companies sell them this way commercially, so they must hold up just fine, right?
My plan was to bend the perimeter out of tubing, run a couple longitudinal pieces for and aft and weld in the horizontals in place between these to support the cooler etc. Between the longitudinal supports and the perimeter, I was going to weld in some aluminum tread plate for a walkway.
Maybe I am getting locked in the idea of building the frame this way because I have the equipment rather than it being the best way.
If you have the choice between a welded up frame, a speed rail frame, or any other type, what would it be?
Thanks again for all the replies!