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dustman

Well Known Member
Have another question in setting the wing Incidence im coming in a little less than 1 deg inorder to get the 1 deg i will have to trim the repair spar to allow it to sit higher in the attach point. As it sits now it needs to come up about 3/16 of an inch to get the 1 deg is this close enough or do I start grinding? Thanks
 
This is really your call but my tech inspector said it best, "Do it right."

If you don't "do it right" and it doesn't work out, then what?

It won't take time to pull the wings, file the rear spart a little, then re-install the wings, and drill the hole. I had to do this on mine and it really wasn't a problem.
 
it may help to check several times

3/16 sounds like a lot - if you have not, I would suggest checking everything again. Bill, how much did you relieve your wing?

My RV-9A wings just slid in and were dead on, only a 1/32 push was needed on one wing.

Perhaps you can pull one wing out slightly and see if the flange moves up (as if it were slightly bound in the down direction)

See if your attach point flange is really oversized compared to the drawings.

Start with the fuselage to see if it is still level (things move and check your level by flipping end for end) (try a different set of levels, check any templates, etc. Calculate the angles if needed.

If you start filing, make sure that you don't run out of edge distance. Mine were close.

Just some thoughts. My apologies if you are already way ahead of me.

Regards, John.
 
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I'm not sure I understand why you'd need to trim a spar to raise it? Or are you talking about the sweep?

I think Van's has indicated that the key on setting the wing incidence is to have both sides be the same.

You want to be VERY careful about grinding the rear spar. Hear me now and believe me later, the "window" where you can drill the hole without violating the edge distance of ANY of the three parts you're drilling through is very small.
 
level

Thanks guys went out and checked the level of the airframe it was off problem solved. Next question min edge distance is 1/4 inch correct?
 
dustman said:
Thanks guys went out and checked the level of the airframe it was off problem solved. Next question min edge distance is 1/4 inch correct?
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It's a 5/16" hole, Minimum E.D. is 2D (2 X the hole diameter) so the center point of the hole must be 5/8" from any edge.
 
When I did mine I fuzzed into the minimum edge distance. Very scary territory here. By fuzz I mean in the black sharpy line. This is one place not to screw up apparently.
 
Make sure you read the supplemental instructions provided on Van's website for sweep and incidence BEFORE drilling any holes in the rear spar. Bob is right. The box in which you can drill a good hole with appropriate edge distance is remarkably small. In my case I seem to remember 1/16" wide x about 1/8" tall, and the hole must stay in this box through all four layers. Good luck.
 
this sucks

I'am almost afraid of drilling the hole at this point. It sure seems like there could have been a little better solution to this issue perhaps a little different designing of the attachent point.
 
You'll be fine. Start with a small drill bit and just make sure you're perpendicular to the rear fork and you go in straight. Part of my problem was that I found a mistake (well, it wasn't really a mistake per se, just a poor drawing) that caused me to slice just a tad too much off the wing spar doubler when I was making it.

That and the fact I didn't drill in straight -- perpendicular to the to the rear fork. I used along drill bit and held it parallel to the fuse. Well, duh.... the fuse behind fork is angled.

I also didn't know how to use a reamer properly and that didn't help.

Even with ALL that, I was only off 1/32" . The odds of you making all of those mistakes are incalculable.

You'll do fine. Just take your time...measure a bunch. Go slow.
 
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Make some drill blocks to guide your drill bit perpendicular to the fittings. I made mine from one inch blocks of aluminum I had but steel would be OK, 1/2 thick steel should work, I think. I made 1/8, 3/16, 1/4, and 5/16 blocks. Center punch the fittings, drop the 1/8 bit into the dent, then clamp the drill block onto the fitting. Work your way up to 5/16. Check the wing incidence at every step! It wants to wander.
 
Bob,

Great link - if you haven't fitted your wings, read it a couple of times to make sure you understand what is going on.

That part of the print is a classic case of a tech drawing person understanding completely but us poor fella's who have to do it being left scratching our heads, or worse, cutting in the wrong place :eek:
 
eyeball and level?

I did not think of blocks but this worked for me. Use 12 inch bits. Hand spin the drill to get the pilot hole started where you center punch the spot. Get all set up with the drill in place. Brace your hand against the fuselage. Check level with a small level on the bit. Then measure or eyeball parallel to the fuselage. The 9 fuselage is square to the spar in that area. I did measure with a tape, but found I could eyeball the bit parallel to the fuselage and that was adequate for me. Perhaps two blocks would be better. One as described above, then one back on the bit for the parallel adjustment and then use the level.
 
You know, I had the avery drill bushing (the one in the plastic housing) and I still screwed it up. It was very tough to get in there what with a c-clamp in the way and all. My next RV is going to be so much better. :D



Stephen Lindberg said:
Make some drill blocks to guide your drill bit perpendicular to the fittings. I made mine from one inch blocks of aluminum I had but steel would be OK, 1/2 thick steel should work, I think. I made 1/8, 3/16, 1/4, and 5/16 blocks. Center punch the fittings, drop the 1/8 bit into the dent, then clamp the drill block onto the fitting. Work your way up to 5/16. Check the wing incidence at every step! It wants to wander.
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