Reviewing the canopy fit and attachment issues - realized that with only four #40 holes at the aft edge center of the plexi there is wiggle room to move the rear window slightly aft, approximately 1/8th inch to increase the 'edge' for attachment.
Looking specifically at Part 3 of 3 (12.3.10) photo #1 --- I need to gain a larger edge distance on the plexi for the center two rivets. If I set up a good drill guide the four existing holes in the plexi can be enlarged toward the front (forward) and likewise when I drill out the four existing holes in the skin they can be enlarged to #30 on the opposite (aft) direction. The combination should move the rear window AFT relative to the fuselage.
The other technique I realized too late - the first couple of holes to secure the back edge of the plexi could be slightly 'slotted' to allow a little deliberate fore-aft adjustment as the canopy is being fitted. In addition be sure to leave a uniform 1/8th inch or slight more on the rollbar end to be sure it can be adjusted aft, and trim the front as the last task to fitting. Fitting is three stages; 1) rough cut to insert, 2) rough trim to adjust that fit and refine edge distance and interference, with minimal drilling and only where it can be 'adjusted' - ergo, center top, aft edges, and 3) a final trimming and smoothing with drilling and securing ALL holes. UPDATE - 12.4.10 - tested drill bits, feeds & speeds, technique and rivets
