<November 29, 2005>

Trim-Tab Rework

I am taking a break from the wings while I wait for a few things I ordered to come in, so it was back to the where I left off with the tail a few weeks ago. I wasn't happy with the trim motor cover plate and the tab-tab itself. I put it aside out of frustration, and now it is time to takle it again. I had another builder over here a few weeks ago and he thought I was crazy for wanting to address such "minor" issues, but since I had already ordered the parts, what the heck.

The first issue was that I wasn't happy with the way the trim motor lined up with the opening in the cover plate. If you listen to the dimensions given to you on the plans, you will be way off. I caught this when I built the first cover, but it was still off, and being fastideous, I couldn't let it go. Besides it was only $5 in parts. There was also the issue of the two aft rivets which held the brackets to the cover, they hit the trim motor and I had to fabricate spacers, and I think I have a solution for this.

After tackling the trim motor cover I turned my attention to the elevator tabs. I just wasn't happy with the way they turned out as they were slightly out of square with the trim tab and the bends were a little... I don't know... just not perfect. I decided to do what many other do and that is to cut off the tabs and fabricate a little rib for the spot. I am a little concerned about screwing this up, but oh well.



Here is the old cover (left) and the new (right). The new one has lines drawn on it where the plans tell you to mount the brackets. Word of caution, don' do it... read on.

If you drill the holes and mount the bracket where Van's tells you to, you end up with the trim motor being offset approximately 1/8" to far to one side.

Here you can see I have drawn new lines to compensate for the mis-alignment. This was a trial and error thing.

After finding the right spot, I drilled the holes. I think you will agree the alignment is much better. For the issue of the shop heads on the two rivets that hit the trim motor (holes pictured here), I decided to try to fix this by countersinking these holes in the cover plate and using oops (NAS1097 rivets). These forward four holes will still get dimled. The coverplate is just thick enough to countersink for these rivets... it doesn't take much.

I got out the Dremel tool and went to town... no turning back now!

Both tabs cut off. It looks pretty rough right now. Gulp!

I got out the files and smoothed it all down square with the trim tab cut-out. After smoothing with the Scotch-Brite, it came out pretty well. So far so good.