Wednesday, September 9, 2015

Trim tab near complete - 3.5 hours

Probably the most time that I've spent messing around with one little piece. It took a whole lot of head scratching to figure out how to dimple some of the holes in the trim tab. I was a bit concerned that I was not going to be able to dimple the control horn without the dimple dies interfering with the side. It looks awfully close. I still have the other set of control horns from the kit (I used the second set that came with the electric trim) and I test dimpled those. Perfect! No interference from the dimple dies. So I dimpled the control horns.I was a bit concerned about the edge distance on the last hole as I trimmed it a bit for a flush fit with the trim tab...it checked out alright.



The last hole that needed to be done was the aft most control horn hole. It is extremely tight to the tab.

Nothing I could think of would fit. The tight space dimple dies I have won't fit. I was set on the fact that I may have to grind down one of my dimple dies. I asked a friend for help too.

I read on the vans airforce forum about a suggestion to make your own dimple die by drilling a hole and then countersinking the hole. That got me thinking.... I thought about using the oak block that I had from bending the tabs. What if I stuck the block back in, drilled the #40 hole, and then countersunk the block.  Well I did just that! Then using the rivet gun with the die holder rivet set, I set the pressure on low and gave it a couple shots. bingo it worked. Not the sharpest dimple but completely acceptable.



Then I set out riveting the trim tab. Probably one of the most tedious and frustrating riveting sessions. Had to be a contortionist with the squeezer and constantly change yokes and flat dies to get the right fit. Ended up drilling out about 8 rivets all together. Very difficult to get the AD3-3.5 rivets to set straight with all that going on with the trim tab. I needed 8 hands holding things. Ended up having to install a oops rivet in the aft most hole of the control horn. Just too darn tricky to get one to set proper in that hole. (Did I mention that I am becoming a master at drilling out rivets!)

Getting good at setting AD4 rivets...AD3 rivets are a bit more challenging. Seems they are easier to slump to one side.