Upsize centre holes of upright joining channel CF-ANG-008 to 4.8mm

On the RHS in particular the 4mm skin hole mismatch the centre holes of the upright joining channel CF-CHL-008 by about 0.8mm. This is not a big deal structurally, as the main connection is between this channel and the outer reinforcing rib 5. This latter part has intentionally had these holes omitted to as to permit an accurate match drill to the upright joining channel holes. The problem is that the access to do this match drill is from the inside of the joining channel. Some holes could be done this way, but there is too much interference with other parts (mainly the box channel) for many of the holes.

The only real way of match drilling any holes in rib 5 is to use the skin as a template. But here the skin has the 4mm holes in the wrong location relative to the upright joining channel. The solution is to recentre and upsize these 4mm holes to 4.8mm and achieving accurate alignment between the skin and the upright joining channel. Then the skin can be used as a template for eventually match drilling rib 5.

After I obtaining an ok from Sling to perform this upsizing to the upright joining channel holes, I got to work.

This mismatch was mainly on the RHS, about 0.8mm. It was much smaller on the LHS, about 0.3mm and in itself not a big deal even for match drilling. But for the most accuracy and given the approval I upsized both sides. The steel of the joining channels was found to be very hard.

I painted some bonderite (alodine) on the drilled hole interiors after cleaninf