These are the exact measurements for attaching the mass-balance arm to the aileron ribs. Something looks wrong, and I think the 42mm and 70mm measurements are supposed to be from the front flange, NOT from the 15mm front bolt distance.

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Comment by Jacques Hoffler on October 5, 2019 at 12:11pm

About how far from the top of the aileron skin is the cutout for the balance arm? Mine is about 25MM, but the arm doesn’t even come close to fitting thru the hole after painstakingly following the drawings. Attached is a photo of my measurement hoping you can take the same measurement.367597E7-1DBE-426C-93C0-8E1110DF5355.png

Comment by Brian A Manlove on October 3, 2012 at 4:27pm

Got the "official skinny" from Roger - the measurements on the drawing are wrong.  The bolt holes are all measured from the front of the rib, @ 15mm, 42mm, and 70mm.  Glad I asked.

Comment by Brian A Manlove on September 24, 2012 at 8:46pm

Thanks Dan!  The differences are, on yours, the bolt holes go at an angle to the arm, the offset off the top is 97 degrees, and the spacing is measured from the front flange.  I'm going to post a scan of that part of my 6-W-12.  On mine, it also has no measurements for the square hole in the front of the aileron - nothing. At least yours shows the top of the hole at 22mm down.  I've had to make a "guesstimate" based on how the arm comes off the ribs (94 degrees on my drawing.)

Comment by Dan Dempsey on September 24, 2012 at 8:12pm

Here's a link to Zenith's drawing that (I think) matches the ones they sent me to do the upgrade.


Comment by Brian A Manlove on September 24, 2012 at 6:56pm

Dan:  It looks suspicious to me, I think when they transcribed the drawing to the 650 plans someone "missed a line" in there. My plans are revision 3 dated 3/12.  

Comment by Dan Dempsey on September 24, 2012 at 5:56pm

I don't have my official upgrade drawing set with me (they're at the other house) but I do have an early draft dated Aug 18 2009 and it shows the 70 and the 42 mm going from the corner (front flange), not the first hole.

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