Longeron Bends
 

Yep.. I read all the post and checked out as many builder sites as possible. Fear Not, I still made it as hard as possible!! Yes I got it done and yes it matches the skin line, still not sure about the 17deg twist on the end but form what I understand it can be tweaked latter.
So, I?m going to say this so that others don?t feel so bad. IT TOOK ME TWO (that?s right 2) DAYS to COMPLETE! I see where other did it in two hours or 20 min? Ha I spent 2 hours just cleaning up one from all the dang marks I put in it so.. top that! Well it?s done and over so I can now get back to joining the aft and center fuse sections. Carry on

You know, I love builder sites but sometimes I think their proliferation puts too much pressure on the builder. Take whatever time you need to complete it. If it's 2 hours, 2 days, 2 months.

For me, personally, this process allowed me to discover the neat song a longeron thrown across the garage can make. Might've taken my two days.

You nailed it!
 

You nailed it Bob.... mine took about 2 days after contemplating 2 days before starting.

Look how relaxed you are with that answer now that you are done and flying Phase I time!

Ha
 

It took me two sets! The first set I bent perfectly and made a drill error on the front engine mount brackets. Set two took me 3 hours to bend up and match drill, practice does make perfect:(

I didn't track the time, just made sure it was done right. In the end, like many other parts of the build so far, it wasn't as bad as I feared, having read everyone's comments on it. I ordered an extra length of longeron angle with my wing kit in case I messed one up, but didn't end up needing it. Come to think of it, if anyone near KS needs it I'm sure we can work something out. I hear shipping a single 17' long stick of extrusion is kinda expensive.

Yep, like $60 for the angle and $200 shipping, ouch

I had the very nice assistance of a previous builder to help with that bending step. I would have been WAY too timid.

I did all the measuring and marking beforehand.
We clamped it in a vice (bolted to a very heavy table) and bashed the **** out of it with a big dead blow hammer while he pulled in the right direction. They came out perfect. It was only a few minutes per piece.

I was thrilled. Use that resource as much as you can. It will make "big" jobs easy.

longeron dies
 

What?? You don't like the Fred Flintstone method???

Me either. I developed a set of male and female bending dies that evenly apply pressure to the horizontal and the vertical flanges of the angle. This greatly reduces the tendancy to twist, and gives great control over the process.

To use these dies, place a strip of electrical tape on the vertical flange to protect it from the pressure points, apply pressure with the vise, release pressure, pull out an inch or so and repeat.


these are cnc made out of 1.25" square 6061. They were made specifically for the RV7 / 9 airplanes.


http://www.bullerent.com/experimental.htm

I'm glad I didn't know that when I bent mine years ago! More pressure!

I was convinced though I was going to find a machine shop somewhere to bend them for me. Turns out I took maybe a couple of hours to do them myself. Just another one of those butt puckering operations that Vans sprinkles in along the way. I guess I can finally claim victory on the longeron bends now that I'm flying!

Wish I'd have known about these dies before I did mine. I ruined my bench vice with all the cave-man work. The heavy pounding literally broke the base. But I got 'em done. Persistence definitely pays off.