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woxofswa

Well Known Member
I have a curious problem. On attaching my rudder, I have the 35 degrees of travel both ways, everything is straight and normal, and I have a perfectly parallel gap between the top of the V/S and the counterweight extension on the rudder.
The problem is the measurement of 2 3/16 degrees that the manual says I am supposed to have between the fully deflected rudder and the inboard edge of the elevator trim tab in the trailing position.
At first try with the rod ends set to the specified 3/4, my bolts all lined up nicely and everything is smooth, but I only had about 1 1/2 inch space for that check.
I took off the rudder, cranked each rod end one full rotation and tried it again.
That moved the gap about 1/8 inch, still way short of the specified number.
The manual says to crank in the bottom one if there is too much travel, but I am hesitant to do that because my rod ends line up perfectly, my gap at the top of the V/S is perfect, and I'm showing 35 degrees.
Is there a chance that the 2 3/16 is a typo?
Any comments or suggestions appreciated.
Thanks,
Myron
 
I had the same problem. Catch 22. After talking to Vans tech support, I went with the degrees and all the other gaps and left the minor variation in the rudder to elevator go by. All the dimentions are targets with the degrees of deflection probably slightly more important.
 
Thanks Orchid.

That makes sense. I'm curious if our kits were in the same batch or vintage. mine was shipped 05/07.

I was going to call tech support, but alas it was after close Friday when I discovered the problem. You've saved the rest of my weekend!
 
Bit of lateral thinking, but wouldn't the elevator hinge adjustment make a big difference to this figure? ie, screw in the elevator, gap gets bigger......
 
Yes it would, but it seems to me that it would be huge pain to adjust that. The bellcranks are already match drilled to the HS bearing, and the pushrod is already set to the proper length as measured by the angle of the forward bellcrank. Re-adjusting the length of the elevator hinges would throw all of that out of kilter.
 
It's no help for you, I'm afraid, but it's just given me a big heads up to get that geometry adjusted BEFORE fitting the elevator pushrod! Good luck with getting it sorted.
 
paul330 said:
It's no help for you, I'm afraid, but it's just given me a big heads up to get that geometry adjusted BEFORE fitting the elevator pushrod! Good luck with getting it sorted.
Click to expand...
Sorry but the elevator pushrod does not have any impact on the dimentions here unless you do some re-designing and I would not touch the design of the elevator-push rod connection from the plans. Bending/bushing etc the elevators go make them farther apart or closer just to meet this setting would be messing with (in my openion) critical design areas just for an eight inch of clearance when you are talking 2" plus to begin with.
It is strickly the rudder bearing adjustment in and out and where it hits the stop bracket
 
Orchid,

I think what Paul was refering to was drawing the elevators forward tighter to the HS, to try and increase the gap.

Paul,

Match drilling the elevator horns happens sequentially before the V/S and rudder are mounted, which is necessary to have the access.
 
A couple more thoughts

It seems to me that the best way to do this would be to temporarily attach all the tail feathers and get the geometry right. Then take the rudder and VS off again and drill the elevator horns and attach the pushrod. That, however, does not help Myron.

It also occurs that it depends to a certain extent how aggressively you deburr the rudder stops as to what the rudder throw and hence the clearance will be.

If you are worried about the clearance, could you not "pull in" the elevator a little as suggested and then adjust the pushrod end eye-bolts? Bit of a PITA, though. I guess the bottom line is that you are satisfied that there is ABSOLUTELY NO CHANCE of interference between the rudder and elevator.
 
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