Cabin frame complete
Moving forward with the canopy frame (roll bar), I drilled the forward section to the joint strip. I also drilled the center joint plate on the forward section. At each step of the way, I continued to check total width and height measurements very carefully. With everything drilled, I took it all apart and deburred all holes and edges. Then, I machine countersunk all of the frame holes. There is a fun trick, machine countersinking an inside and outside curve. Patience is the key.
I primed the inside of the frame parts (anything I couldn’t prime just before interior paint) and got the forward sections assembled back on the bench for riveting. Solid rivets are squeezed on the forward section and attach strip, then the aft section is installed to close up the channel. Pop rivets are used here. (Tool Alert) I am totally kicking myself for waiting so long to purchase a pneumatic pop rivet gun. $30 at Harbor Freight right up the street. Just laziness on my part. I was looking at all of these pop rivets that had to be installed on the cabin frame and was not interested in spending half of my Saturday squeezing these things only to end up with a sore arm. The pop rivet gun is AWESOME! I wish I would have had this thing on the rest of the project. Just pull the trigger and, pow, done, on to the next one. It took all of ten minutes to set all of the pop rivets. Super cool.
At about this point, David (-7A builder) came over for dinner and an evening of great RV conversation. I very much enjoy talking RV construction in the garage, and we did for the better part of four hours :).
Back to the project at hand, it was time to figure out how this contraption gets installed. I spent a lot of time clamping, measuring, and marking the attach brackets to be sure I knew what I was doing. I found (as others have) that there is a bit of interference between the brackets and the seat back brace thingy. I used the Dremel to cut out a little notch on each side to clear the bracket. With some final careful measurements, I drilled the brackets to the fuselage and the cabin frame. The top bulkhead brace is required for final alignment before drilling the brackets, so I match drilled it at the same time. Note that my kit includes the tip-up AD modification where the top brace attaches to the bulkhead and top skin.
Once all of the cabin frame attach stuff was complete, I decided to fabricate a cover for the top brace. Not too much to it, but it took a little time. I’m thinking I might want to put a light or something overhead. To complete this update, the label printer that I ordered arrived. This is the same device that Walter used. It can print on shrink wrap tubing. Great for labeling wires.
