Sidelugs

One of the last steps of the welding process is to weld the sidelugs on the bottom longerons. I've contacted many local sheet metal shops to see if they could bend the 0.025" thick 4130 sheet I had. The bends required are close to each other and shops were generally reluctant in doing the job. I therefore decided to make them myself.

My initial design looked like this:

 

The original sidelugs did not include the step as you can see above. I needed to add this step in order to accomodate the new thickness change of the lower longerons. However, making this out of one piece with the few tools I have was a little complex so I decided to split it into two parts:

 

 

Had to make a holding tool to make sure that the metal was securely held in place. I used two pieces of 3/8 thick mild steel with a little radius on the corner of one of them. Here is what my bending setup looked like:

 

 

 

 

I used screws going through both plates to provide additional clamping force near the edges. The bar you see on the right is a piece of 1/2" thick steel I used to hammer the base of the protruding part of the sheet metal. It took a lot of effort to bend this only with a hammer. After two nights of work, I had the four pieces bent the way I wanted:

 

 

 

The last step before welding to the fuse is to trim the excess material used to clamp them in place. I left this job to my welder since he is going to determine their final location and might need extra length.

 

Next post will be about the final welding and if everything goes well, about the ferry back to my home airport!