I had previously over-deburred the edges of the cabin frame channels (to remove “waviness”) to the point that I couldn’t get adequate edge distance on the straps holding the aft and forward frames together. I ordered new channels, and today I redrilled the new aft channels to the F-631E joint plate. I also trimmed the bottom edges of the aft channels approximately 1/32” to adjust them to the overall height called for on DWG39.
