[Michael Burbidge]

I'm about to match drill the T-905 attachment bracket to the inboard tank rib. The plans and instructions don't really say anything about placement. The plans simply show it snug up against the nose of the rib and parallel to one side of the 'H' shaped strengthening indentation in the rib.

Is that how you determined the placement of the attachment bracket. It seems like its placement would be critical since it must match up against something on the fuselage.

 

[airguy]

No - you're correct. There is a full size template for the 905 which shows the rivet hole locations, but after drilling those in the 905 you have to backdrill the rib holes through those, so there is no sure way to duplicate an exact location fore/aft for the 905. I'm assuming there will be some shimming operation going on when it comes time to join the tanks to the fuselage, there are no hints given in the instructions for this at this point.

I snugged it up as well as possible in the nose, made sure I was square with the orthogonal tab, and drilled it.

 

[alpinelakespilot2000]

I'm assuming there will be some shimming operation going on when it comes time to join the tanks to the fuselage, there are no hints given in the instructions for this at this point.

No worries, there is a wide degree of latitude on how big/where to locate the fuselage attach angle when you get there. The only thing that's really fixed is where the bolts go through the fuselage. No shims will be necessary. Once you fit the wings you'll clamp the fuselage angle to tank angle and back drill through the former from inside the fuselage. One BIG hint. Don't cut down the fuse angle (or shape it) until the fuselage holes have been drilled through the angle. This will help to insure that you have edge distance when all finished. As mentioned above-just make sure the vertex of the tank attach angle is parallel to the stiffening "bead" on the inboard rib. Hope this helps.