Comment

Comment by Joseph F. Truncale on August 19, 2012 at 6:54pm

John,

I'd appreciate seeing a photo when you're done.

Thanks,

Joe

Comment by John F. Schaefer on August 12, 2012 at 7:31pm

Joe, I was recently exposed to your solution to the terrible pitch/roll coupling problem.  It's great; I am in the process of doing it, and I thank you.  I do take issue with your response to the question from Harman re need for the 2 outer sleeves.  I can see no need for them, other than redundancy.  The inner tube prevents any motion other than along the tube axis ... and the through bolts accomplish that chore.  I am going to assemble and install without the outer sleeves:  if I find I am wrong I'll be the first to let you know.  Again:  thank you!

Comment by Joseph F. Truncale on June 26, 2011 at 6:31pm

Finally disassembled and took pictures with dimensions.  I'll post the pictures and when they disappear from the front page you can find them again on "My Plane".

By the way, I  goofed in my description above. The inner torque tube is not solid, it is tube, and the size is on the new picture.  I got my projects mixed up.  I used solid to make inserts to go in the elevator push/pull tube ends so that I could screw new rod ends in (GMM-4M-470 Aurora Bearing), $15.75 ea. from Aircraft Spruce (ouch).

Best,

Joe

Comment by Ken Ryan on June 26, 2011 at 11:30am

Also very interested in seeing the anti-rotation bracket.

Comment by Ken Ryan on June 26, 2011 at 10:46am

This looks good! I too would like dimensions for this. Maybe you can post them?

Comment by Joseph F. Truncale on June 21, 2011 at 7:03pm

Appreciate the comments.

Harmen, the sleeves are what keep the center section with the bellcrank stable in its original position.  Without them, there would be no vertical or horizontal constraint.  Your point is well taken though on the rearward friction.  It should be a force equal to that on the "control stick forward stop against the seat from bearing" as Don describes below.  The contact area is less though, so the actual friction is tbd right now.  So I agree a bearing may be needed if grease isn't sufficient.  I did try to make the tube ends square and flat to spread the load.

And, Don, your assumptions are correct. You described the construction perfectly.  I will get you the dimensions (have to disassemble again first). On your question w.r.t. elevator cable tension, the front part of the torque tube + the internal torque tube + the rear tube with flaperon bellcrank are all one continuous structure.  So the elevator cable tension pulls the bellcrank (center section) rearward which pushes the rear flaperon tube section rearward, which pulls the whole torque tube assembly rearward as before. So I have the same contact on the seat front bearing, and the flaperon bellcrank boltheads move rearward as well.

Thanks again for your interest and clear comments.

Best,

Joe

Comment by Don Herbel on June 20, 2011 at 10:37pm

Great Idea! I assume the short sleeves bolt through the cut off pieces of the original torque tube and also through the internal torque tube but not to the center piece that contains the welded brackets for the elevator bell crank? Would like the dimensions you used and the part number of the rod end.  On the original configuration, elevator cable tension keeps the flaperon bellcrank bolt heads from contacting the rear channel by "pulling" the original torque tube aft and keeping the control stick forward stop against the seat front bearing.  How does the modification accomplish this?

 

Comment by Harmen van der Velden on June 20, 2011 at 7:19pm

Wow, I really like this solution to the old problem, Considering changing my rigging (in the off season)  Do we actually need the external sleeves or are they just an extra safety ??. Also was wondering about the force from the elevator cables to the rear. This may cause more friction on the rear part of the belcrank tube to the rear part of the tube, may need some kind of bearing here. Still I think so far the best solution I have seen.Keep up the good work !!

Harmen