First Compression Struts

Spent the afternoon fabricating and tack-welding the first four compression struts.

These are pretty simple parts, but they are the first metal parts I have fabricated in a long time.  I have been kind of reluctant to work on these.  They are not difficult, but my confidence in my abilities has been a bit low.  But these look great.

There are a total of 12 compression struts.  The remaining eight are of a somewhat different configuration.  Some of them are built from 5/8" tube instead of the 3/4".  The ends, which are Piper Cub parts and not easy to fabricate are sized for the 3/4".  I am thinking of fabricating short 3/4" transition pieces.  So far my attempts in that direction have not been particularly re-assuring.

Standard procedures requires a bird-beak transition in the larger tubing.  So far I haven't been very successful in figuring out how to cut the bird-beak. 

It will come.

COMPRESSION STRUT JIG

This project has been on the shelf for far too long.  This evening I finished up the jig for fabrication of the compression struts.  The compression struts are braces between the wing spars counteracting the pull of the drag wires.

The upright on the left has a rail on the bottom that runs in the groove, maintaining alignment between the uprights while allowing that one upright to be adjusted for length.  It is held in place with a C-clamp.

The components of the first strut are in place ready to be tack welded.  Actually, not.  They need to be cleaned up first. The metal on the jig will, hopefully, prevent me from setting the plywood on fire.  The middle brackets ensure that the tubing will not drop out while the tacking is under way.