Thursday, March 16, 2017

New Fittings Done - Big Mistake

 I have all the new set of fittings, formed, welded and painted.  Unfortunately I have to remake all the welded fittings.  I left the holes to be drilled to final size after welding just to be sure the holes were well aligned even if the fittings moved slightly while welding.  It also allowed me to use 3/16" and 1/4" screws to hold the fittings while welding instead of a bunch of different sizes.  It all worked the first time when I remembered what I was doing.
 The 2 bolt holes along the bottom of the fittings should be drilled so the inboard hole is 1/4" and the outboard hole, in line with the brace wires, should be 0.377" (letter V drill).  Instead I reversed them. When I made the first set of fittings, I made the template with the inboard hole 1/4" and the outboard hole 3/16".  The assumption was that I would only drill the outboard hole.  I should have looked carefully at the drawing and I would not have made the mistake.  Instead I thought the bigger hole get's the bigger drill, etc.  I'm making new parts.
To make sure I don't make this mistake again I've made new templates.  I've stamped the finished hole sizes on the templates and reversed the size of the 2 problem holes.

This is so annoying.  I was ready to start sawing the wing spars.

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