<April 30, 2007>
Left Aileron Rigging & Flap Install
I just wasn't happy with the aileron rigging set up I had made yesterday, it seemed sort of sloppy and had a lot of play in it, so I tried a new approach. Since Van's had replaced my flap skins (they were bent incorrectly), I decided to use one of the old flaps to make myself a jig of sorts. I cut a 1" wide strip of aluminum from the old flap, with the intention of using the pre-punched holes to assist me with the alignment. I think it worked pretty well.
I enlarged two of the pre-punched holes to accept some scrap AN3 bolts and bolted my jig-thingy to tooling holes in the wing.
The it was a simple mater of drilling a hole, inline with the pre-punched holes, which I used to align the trailing edge of the aileron. I am just holding the aileron in the proper location here.
I then reinstalled the aileron alignment doo-dad and made some adjustments to the small pushrods to center the aileron trailing edge aligned correctly.
Once I was happy with the setup, I enlarge the hole in the jig a little bit with a file and inserted a short AN3 bolt through the hole to help me keep the aileron still during fitting of the flap. I put some tape over the head of the bolt to keep it in place (not pictured).
I drew a line down each flap hinge 3/16" from the edge. This is my do not cross line as the plans call for a minimum 3/16" edge distance on the flap hinges.
I used some small c-clamps to clamp the outboard end of the flap in place, aligning it with the aileron. Then I clamped the inboard end of the flap hinge to the wing. Wouldn't you know it, to get the proper alignment I've crossed the my 3/16" edge distance line. Crap! Oh well, I understand that this is a fairly common issue. I am probably going to order some wider hinge stock for the wing side of the flap hinge.
When I built the flaps, I installed the hinge on the flaps exactly at the 1/4" mark as specified on the plans. If I had to do this again, I probably would install the flap hinges at 3/16" which would result in me having a bit more room to play with on the wing side of the hinge.
The alignment looks pretty good, but it is moot as I will need to redo it once the new hinges arrive. What's strange is that the distance between the flaps and ailerons is a little wider aft (top in the picture) than forward. It is only about 1/128-1/64" but it is visible (to me). I checked and rechecked the aileron to flap alignment and they are both at exactly the same angle as measured with a digital level, so I am not sure why this would be.