Fri May 07 2021

Fitting panel brackets

After thinking about what the mechanism needs to look like to actuate these popup tipup arms, I decided that I needed to better understand how the latch handle and aft canopy latch linkages work.

So, I started doing work that will bring me back towards that area. One of the first items that I worked on was fabricating the brackets which mount the panel to the canopy decks. Here I'm match drilling through the panel to one of these F-721C brackets.

With the F-721C brackets holding the panel in position along with the factory-supplied upper, forward fuselage ribs (not pictured), I started work on the two inboard brackets. After forming them, I drilled them to the canopy deck, and to the panel. Unfortunately, something shifted while drilling the first of the two holes to the canopy deck, and the bracket was no longer positioned correctly. I had a gap between the canopy deck and the bracket flange. Arg, this is going to be a pain to fix. I can fabricate a new bracket, but how can I match drill it in the correct position to a hole which is buried behind the bracket itself. If there were more clearance, perhaps I could use the angle drill from behind, but under this canopy deck, there's no room for the angle drill. Grr.

Here's what I came up with. Two pieces of .032 scrap visible here with a single #30 hole is clecoed (through a .032 shim) to the hole in the canopy deck. The other piece of scrap aluminum is hidden behind this one and serves as an .032 thick spacer to all the shim to be slid out after removing the cleco...

...and an oversized replacement bracket to be slid into place.

Extra clamps added to hold everything in relative position before removing the whole mess to match drill the new bracket to the #30 hole in my piece of scrap. Had to wrap up for the day before I could finish this up.