|July 2, 2004||HOME|
Van's instruction manual warns you that the elevator horns will probably not be in alignment and implies you should drill absolutely perpendicular holes so that the horns won't pull the elevators out of alignment (with each other). That makes perfect sense. If they were out of alignment and you precisely measured and drilled at the same relative spot of each horn, the holes would be the same relative to their respective horns, but not to the relationship of the elevators.
Well, that probably doesn't make any sense to anyone but me and that doesn't matter. It doesn't matter because I carefully checked and the elevator horns are perfectly aligned. You can't really tell that by the picture below. In fact, the picture makes them look somewhat off. I measured from the outer ends of the rule to the trailing HS spar with equal contact on each horn and the elevators perfectly aligned with the horizontal stabilizer. The variation was less than 1/64th. I can live with that.
Happy with the alignment, I measured per plans and marked to drill a first #30 pilot hole. Exact placement here is not critical. It's the relationship of the two hole (one in each horn), that is critical.
The first pilot hole drilled.
Here is how alignment of the horns is maintained. The elevators are installed (no need for nuts or torquing) on the HS and clamped in alignment. Both elevators are carefully checked to assure the same alignment point on both sides. I left them clamped until all the drilling was completed even though the plans recommend removing the pilot-drilled elevators and final drilling them one at a time.
I drilled a dry hardwood block as a drill guide to get true perpendicular relationships between the horns and the final bolt assembly. Works great, if you get perpendicular! I used the drill press, but did something wrong. It's probably the fault of all the steel shavings my husband left on the drill press table. I won't scream at him for that, but he may have to ask permission before he gets to use the drill press again.
The measurements below (see the 2 insets for a better relationship view) show how much the angle was off. Of course, it should have been exactly 90 degrees.
I cleaned up the drill press and double checked my alignment before drilling another hole. The results were perfect! Time to drill the elevator horns.
Here the block is being aligned with a #30 drill rod to assure proper alignment. I clamped it, drilled it, removed the block and final drilled all the way through in 2 steps, using the final drill to just ream the last couple thousandths for a good bolt fit.
The fit was perfect without any binding or pulling or realignment of the horns. What I really don't like, is the use of washers as spacers. It just seems hokey. I will make some right-sized spacers that are each one solid piece to replace the washers. If I can't turn them adequately in a slow drill chuck, I'll try it on a friend's lathe, but please, one washer spacers is OK, but let's not stack them up. Ugh!