It’s really good to be moving on from the rib prep … much more interesting. The next steps involve preparing parts for the aileron torque tube & flap brackets.
After separating and deburring the parts, they are clecoed together and final drilled #30. I used my #30 reamer. I also marked each piece. The bottom flanges are final drilled #40 and dimpled. The top holes are not since they fit under non-dimpled holes where the walkway fits.
The bracket flange edges have a small radius gently filed so as to allow them to nest snuggly inside the rib flanges (see line in picture). Then after clecoing in place, the bracket/rib web holes are final drilled.
I ended up with a rib flutes interfering with the fit of the brackets in the rib. So …
Do not flute between the rib holes where the bracket flanges locate. Or be very careful to flute exactly centrally in the space between the holes.
I flattened the flutes as best I could.
The edges of the flap brackets are quite jagged, so needed attention from my Vixen File. Then the usual grinding wheels (medium & fine) assured a nice smooth edge finish.
Care is required to make sure the inner brackets are matched to a rib with no dimples on the top flange, since it is under the walkway! This is only an issue if you have dimpled the top flanges of non-walkway ribs (Vans recomend doing top flange dimpling after ribs have been attached to the spar, but for convenience I had marked non-walkway ribs and done thier dimpling already)
I used my pillar drill to match drill the brackets to the relevant rib.