Control Stick Pivot

[alaskabearhawk]

Fix proposal.pdf When making the U-channels for my control stick assembly I messed up and drilled the holes out to the 3/8ths bushing size instead of leaving it at 1/4in. I have two solutions. First is to do what is attached. If that isn't acceptable, I can always put in Heim LSS-4 bearings like Russ Erb did. What do you guys think? BTW, there's a link to a pdf in there somewhere. Once this was posted it really did weird things to the files and I have no idea why. Also, one of the pictures is from Wayne Massey's build and apparently what I should have done. [ATTACH]n1263[/ATTACH]

[marcusofcotton]

I'd recommend going with your fix but using a thicker wall 3/8 tubing, then drill it out to 1/4" to eliminate the .009" slop in the joint. Free play in the controls results in higher workload and less precision when flying and increases the chance of flutter. I don't recall specifically what Russ did in this area (too tired to look it up right now) but do recall that he worked at reducing play.

Mark J

[alaskabearhawk]

The way the controls are, I can't see where the pivot bolt would allow for any flutter. The aileron control cables are in tension in a closed loop and the connecting rod that runs through the bottom of the stick assembly is the solid link that provides a point of leverage. The control sticks just provide the leverage to move the entire cable assembly and as such the stick pivot operates independent of that closed-loop cable assembly. All a loose pivot point would give is a feeling of looseness in the stick while flying, but not looseness in the system. The .058 is what is spec'd in the plans. It doesn't seem like the 1/4 inch hole in the .062 plate would provide a bearing surface for the pivot bolt that would be durable enough to last and would quickly wear to the inner diameter of the main bushing. Even the bushing in the stick is .058 and that would have the .009 play regardless. But, a good point nonetheless. Russ's solution is a good one and can be made at any time.

[DRLPatrol]

How come the pictures are not showing up? The "Fix Proposal" pdf is but not the pictures, attachments.
Doug

[alaskabearhawk]

Go to "User Settings". At the top left of the User Settings box there are four tabs and click on the second from left that says "Account". Scroll down to the section named "Conversation Detail Options". Make sure the "Show Images" box under "Visible Post Elements" selected. That should do it.

[DRLPatrol]

The box is checked. I get all the rest of the pic's on the site. Oh well.
BTW I really like all your YouTube videos. I just started a belt grinder loosely based on yours, thanks.

Doug

[marcusofcotton]

The box is checked. I get all the rest of the pic's on the site.

Doug

I'm in the same boat as you on this Doug, running Chrome.

Mark J