Brief Description: Drilled tail wheel spring hole.
Drilled the tail wheel spring today, what a PITA!
Used a jig made by a friend to make sure the hole was going to be in the correct location and the correct angle 24.3 degrees. Drilled a smaller 3/8 hole first and then inserted the jig guide and fine positioned the jig so the pointer intersected the AN4 bolt between the two mounting angles. Once happy with the position I clamped the jig onto the VS backer plate which was bolted to the VS spar using welder clamps. I then used a special 5/8" bit that had a square milling end on it. This allowed the bit to start cutting at the bottom of the hole without grabing or binding which a normal bit would do.
The result was good but I think the effort was way more than it should be, not to mention the machining and special tools required. I personally don't think it is realistic for Sonex to expect a typical builder to accomplish this task successfully. The design may be OK and provide proper support for the tail wheel but if the hole cannot be drilled without special jigs and tools, I think a different design is warranted or Sonex can predrill this for the builder or Sonex can provide a weldment to provide support for the tail wheel.
