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Elevator Counterweight to HS Clearance

rockitdoc

Well Known Member
Sponsor
The plans indicate this clearance to be 0.125" = 1/8"

I have 1/16" but there is no way to adjust this as far as I can see without removing some metal on the outer edge of the HS.

Is this how the clearance is 'adjusted'?

Thanks, in advance as usual.

S
 
Is that 1/16" along the entire length of the counterweight? If it is 1/8" at the back of the horizontal stab and narrower near the front, you can adjust the hinges to make it straighter. Inboard should be shorter and/or outer longer to angle the counterweight outward. If the counterweight is already parallel to the stabilizer tip, then you could check the hinge brackets for square or (carefully!) bend them to be just a bit more outboard. Or you could remove 1/32" from both the counterweight skin and the horizontal stab skin. Personally, if I found the hinge brackets to be perpendicular to the rear spar, I'd trim the skins rather than tweak the brackets.
 
Is that 1/16" along the entire length of the counterweight? If it is 1/8" at the back of the horizontal stab and narrower near the front, you can adjust the hinges to make it straighter. Inboard should be shorter and/or outer longer to angle the counterweight outward. If the counterweight is already parallel to the stabilizer tip, then you could check the hinge brackets for square or (carefully!) bend them to be just a bit more outboard. Or you could remove 1/32" from both the counterweight skin and the horizontal stab skin. Personally, if I found the hinge brackets to be perpendicular to the rear spar, I'd trim the skins rather than tweak the brackets.

The aft edge of the left counterweight has a 1/8" gap with the HS, the fwd edge is 1/16". The right elevator counterweight has a 1/8" gap aft and a 3/16" gap fwd. Changing the elevations of the hinge heim joints can fix this easily, I think.

Thanks for the suggestion.
 

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  • Elevator-HS Clearance at CW.jpg
    Elevator-HS Clearance at CW.jpg
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Yes, that is what I was describing in the first part of my post. Make the adjustments before drilling the elevator horns.
 
I did lots of small adjustments to rod ends to get this spacing right and also to get clearance of leading edge with full "range of motion". Lots of little adjustments. In the example photo you show, I'd move the outboard rod end out a turn or inboard one in a turn, depending on current clearance of leading edge, then re-check and continue until you're happy. It can take a lot of tweaking. Most importantly, be sure you have enough of the rod end secured in the nutplate.
 
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