[March 17, 2006]

So far I have spent more time on the trim tab than I have on the VS. Just goes to show you that a part that only has 6 pieces can be very difficult. After getting some responses from VAF, as well as my own thoughts, I am going to get another trim tab.

Here is what I think is one of the problems that is causing me issues. The spar for the trim tab is a "Z" shape. When the bottom of the spar was riveted to the trim tab, to cleco the top skin onto the spar, I needed to pull the skin to the spar about 1/32" - 2/32". This pulling causes an inward deflection in the skin and something pretty much impossible to bend out with the trailing edge. That explains my inward bow of the skin, and how I screwed up the first skin.

Also, the root bends of the skin need to be more metal. My bend line was inline with the marks on the trim tab skin. The problem with this is that I had edge distance issues with the root end and needed to pull the top and bottom of the trim tab together to get proper clearance. This is what probably cause the twist in the trim tab.

With all of that in mind, I hope that I can help out the other builders out there to get the trim tab done on the first try. This is the first thing I have ran into in the kit that has disapointed me with Van's. When they put in the description "So, your #*!@ tab didn't quite come out the way you wanted it?" for the part in the webstore, you would think that they would re-engineer it. Who cares that it is only 13 bucks. For me, its not a money issue, but a frustration issue. Everything else in the kit is so great thus far except for this.

The trim tab really needs to have a small rib made for it (like a lot of builders do already - most call it a riblet. And while they are at it, a rib for the left elevator also to eleminate all this bullshit bending.

I not going to order the trim tab just yet. No sense in Van's taking more of my shipping money. The wings are due soon, and I am moving houses so the project is on halt until I get a house, get settled and get my workshop going again.

This is a pic off of rvproject.com. I noticed how close Dan did the bend. This gives him a bunch more material to work with on the bent flanges.

This show how the spar was slightly bent forward. In this pic, it looks like it is 1/32". When you pull the top skin and the spar together, it causes a sag in the trim tab surface. I found it nearly impossible to bend the spar once it has been riveted to the bottom of the skin. Next trim tab skin I will take a much closer eye to everything when it is clecoed together. This is just another reason why the bend needs to occur first before you rivet in the spar, like my original trim tab was done.



Last Modified: September 4, 2017