A jig made by a friend to help me drill the tail spring hole in the VS spar.
Jig consists of a 5/8" ID steel tube welded to a plate at the required 24.3 degree angle. There is also an aluminum plug that fits into the tube and a long sharpened rod that slides through the plug. The plug and rod will be used to locate the jig plate to insure the hole will hit the AN4 bolt between the two angles on the fuselage bulkhead. I plan to drill about a 3/8" hole ( may have to enlage it) free hand through the VS spar at the pilot hole location. Then I will clamp the jig to the spar and use the plug and rod to fine tune the location. Once I have the correct location where the pointed rod hits the AN4 bolt in the center between the angles, I will clamp the jig plate to the VS spar. Once the jig is clamped I should be able to drill the 5/8" hole through the jig tube at the correct angle. Actually I will drill the hole slightly undersized and finish with a 5/8" reamer. I may use the existing AN3 hole in the VS spar and drill the jig to the spar to insure it does not move when I drill the 5/8" hole.
Sure is nice having a friend with a machine shop in his basement and is willing to make jigs and do small machining jobs.
