Michael Burbidge

Michael Burbidge

Well Known Member
I'm working on mounting my rudder. The mounting brackets on the vertical stabilizer are in line. I can put a straight edge across all three. I very carefully installed the rod end bearings to the depth on the drawing. (top 51/64, middle 59/64, bottom 1 1/16, assuming the human eye can see 1/64 of an inch)

I installed the rudder with a bolt through the top and bottom rod end bearings. I cannot get a bolt in the middle rod end bearing. It looks like it is short about 1/16 of an inch.

I cannot screw the middle bearing out because it is already near the limit of only half the threads being in the nutplate. But there does appear to be plenty of room to screw the top and bottom bearings in, without the rudder binding anywhere. How much can you deviate from the plans in terms of how deep the rod ending bearing are screwed in?

I have checked and rechecked all the measurements. And they are all very, very close to what is specified in the drawings. Is it odd that the middle bearing is off by 1/16 inch? Did you have to deviate to get the bearings to line up?

Thanks,
Michael-
 
had to deviate too

also be careful to have rudder horn gap to stab parallel AND be sure rudder doesn,t hit rear vert. flange on rear of vert. Stab at full rudder deflection.
 
Dimensions listed

Similar dimensions for my 7 had similar results. Vans said that the dimensions were just a starting point, adjust as required. After the hinges were lined up I checked my rudder swing and found much more than 35 degrees before hitting the stops. Much more adjustment later everything worked...except those starting dimensions.
 
I had the same issues with mine, I had to set my center bearing in a full turn beyond the "starting point" in the instructions, but it's happy now. Once I had it hung, I realized that my rudder stops were not hitting and I was (am) getting too much throw on the rudder - so I'll have to rebuild those stops. I am using the Delrin internal stop, not the plans-built external aluminum stops.
 
Have you already drilled the vertical stab front spar to the the fuselage yet? If not, you still have a chance to get the hinges in line using Vans' measurements, as the lower part of the stab (below the skin) still has a lot of flexibility. I tried to mount my rudder to the vertical stab on the bench (no fuselage yet), and found that the center bearing bracket on the stab was 1/16" out of line with the top and bottom two. Pulling a string through the rudder hinge bearings showed them to all be in line. The actual problem was there is a slight bow in the stab spar. Vans told me that there is enough flexiibility in the spar below the skin that it can be adjusted by adjusting the front spar-to-fuselage attach point. I plan to run a taught thread through the stab brackets as an alignment indicator when mounting the vertical stab.
 
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Is the issue possibly that the bottom bearing dimension.... 1 1/16" extension, might be measured from the face of the rudder spar and not from the face of the doubler plate? That would mean the bottom bearing would be screwed in a little more, making it closer to inline with the top and middle bearings (?)

The arrows that show the 1 1/16" in the drawing aren't very clear.

Just a thought/wondering.
 
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