<September 26, 2005>
Bent Trim Tab Ends
Wow, has it really been a week since I have been in the shop?!?! The tail is winding down and I haven't been pushing myself as much lately, instead I have been trying to get some projects done around the house. Anywhooo... tonight I managed to make it back into the shop and bend the trim tab ends. I feel the results could have been better, but they are good enough, and thats all I ask for.
Update… Read my comments on Trim Tab bending posted in the Van's Air Force forums.
First I started by bending the trailing edge using the bending brake I had constructed for the elevators a few weeks ago. Nothing too challenging here.
I then did as the instructions said and constructed a bending form from some 3/4" MDF I had laying around. I used double-sided tape to tape the form to the trim tab, to prevent it from slipping while bending, and clamped all of this to my worktable.
Using some scrap wood, I bent the bottom tab down first, then the upper tab up (trim tab is upside-down on bench). I then followed up by using the rivet gun and flush set with the pressure turned way down (10psi) to smooth out the tabs/bends. This worked OK, but even though I used some scrap wood between the set and tab, the tab still got dinged up a little. Oh well... paint will hide these "features".
I followed up by bending the outboard tabs, and then I clamped the trim tab in place in the elevator to check for fit. It isn't perfect, but its pretty good. I wrote "No!" on the elevator to remind me not to rivet those holes.
Here you can see that the gap between the trim tab and elevator is ever so slightly smaller aft (top of pic). One of my bend lines must have been slightly off-square, but is so minor nobody will notice.