Longeron bend help needed.

Hi Group. Two days ago with a friend help (none of us with previous experience in bending longerons) made the longeron bend. It was quite frustrating, I have to say, but after a couple hours of hitting the angle we achieve a pretty descent fit with the template, I think, within the tolerance needed.

However, the left one, came out with a residual vertical bend that I was been unable to eliminate. It is between 33 in and 66 in from the front, were the error respect to the horizontal is between 1/8 and 3/16.

I'm looking for advice in order to correct this. Do you have any ideas? I'm in Chile so I REALLY don't want to have to purchase this again...

Thanks a lot.

Best regards.

Gonzalo Gimenez
RV-7

A little late...

... to help you Gonzalo, but I still say that clamping what will become the horizontal faces of both longerons back to back and making the long bend on both at the same time is the way to go. No hammer or dies required, just body mass and a vice with protected jaws. Having the two faces clamped together goes a long way in preventing the out of plane bend.

What Miles said it how I did it: Longerons clamped together. Regardless how you originally did the bend they can be clamped together at any point.

I would also suggest checking the downwards bends with the sideskin for proper alignment. It hugs the F-705 bulkhead pretty close and even if small adjustments are possible at drill time, it so much easier to adjust now than while match drilling to the skin.

Bend

Gonzalo
Clamp it in a vice with wood to protect it and use body weight to gently flex the longeron.
If I understand correctly, the deviation is in the horizontal with respect to the final position in the plane. If so, when it is installed, the flex may not be an issue. It is clamped into position for final drilling. The side curve, downward bend and twist a very important. They need to be as close as possible to the parts. Use the Aft Deck to compare the curve and the side skin to compare the downward bend. You got this. You can do it. Build on.