2019 - Triplane - Spar Bracket Bushing Straps

The spar bushings on the fuselage get reinforcing "straps" welded over them.  To make the straps, I needed to bend some .063 steel strip around the bushing.  An excellent how-to article in EAA Sport Aviation showed how to do it, but to do so I needed tools I did not have.  Mick A., a fellow member of my EAA Chapter is building a Mustang II, and has a hydraulic press.  So I went over to his garage shop Saturday to use his press.

To make the reinforcement straps, I needed to make a bending jig.  I was able to make the jig components myself out of steel round and square tube and plates, but found my gas welding rig just didn't have enough heat to melt the thick steel of the jig.  Mick has a TiG and Mig welding rig and said it would be a piece of cake to weld the jig together with the MiG.  And so it was.  I had never seen MiG welding before.  It was perfect for this job.
   
With the bending jig tool, the actually bending of the straps was trivial on the hydrylic press.  You can see Mick's MIG welds in this picture.
   
It only took a few minutes to bend eight straps.  Here's a better look at the bending jig also.
   
Looking ahead at building the cabanes for the upper wing, I have to make four steel pins.  Mick has a lathe -- I have never used one -- and showed me how to make the pin -- using hard plastic stock instead of steel.  Great tool!
   
 
   
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