Wed Mar 11 2009

Deburring and fitting F-695 gussets

After work this evening I used a milling machine to trim back the face of this portion of each of the El Cheap-o squares which I bought from Enco. I talked to one of their customer service reps and they said all the sets are like this one, so they couldn't send me a replacement; however, they did credit my card for the amount of the set. This slight modification allows the large block to lay flush against the edge of a piece of sheet metal.

After getting home and taking Snickers for a walk, I deburred some fuselage parts.

While looking for details on what size to drill the F-7101 web for the fuel line, I noticed this detail. It looks like I was supposed to use that piece of .063 to make these gussets. Dang. I guess I'll have to order a new piece.

Hrm...after looking back in my log, I see that the piece I cut up was 3 7/8 x 11. Since the short dimension on this gusset is 4 1/32, that can't be the piece I was expected to use. Maybe there are pre-cut gussets floating around here somewhere.

OK. After some more searching around I found 'em. Whew.

I laid out the hole patterns on one of the F-685 gussets per the plans, but found that the hole spacing results in bad edge distance. Not really a surprise considering the fiasco I ran into while following the plans for the F-684 gussets.

I decided to do some investigation about how this thing is supposed to fit before moving on and found another problem. The longeron is angled downward (up in this photo since the fuselage is still upside down), but the top flange of the firewall angle is horizontal. If I try to rivet this gusset to both pieces, I'm going to end up with a wedge shaped gap along one of the edges...most likely the edge adjacent to the firewall.

Here, with the gusset clamped into place you can see the magnitude of the angular misalignment. I'll have to do some research on this on the net.