Duel Yokes.. Need your help.

[Trevor Hale]

Hey Guys,

Please tell me what I am doing wrong.

http://www.mycockpit.org/photopost/s...php?photo=2717

http://www.mycockpit.org/photopost/showphoto.php?photo=2715

http://www.mycockpit.org/photopost/s...php?photo=2713

I get good response from Pilot to coPilot with positive movement with every little movement. But when I go Copilot to Pilot, there appears to be some slop and the controls slowly go out of sync.

Please help! I am about to go nuts

Thanks,

Trev

[Westozy]

Hi Trevor,

I see you have used the same method as my controls. In your third picture it is hard to see how you have locked the rope to your yoke axle pulley. Is there a problem there? Are you using nylon rope? Nylon will stretch over time. If so, I would dump it in favour of stainless steel wire rope (1.5mm - 2.0mm diameter). I used 2mm SS wire rope and my yokes have been synchronised without any slippage for over two years now, I have never had to adjust it. Also with SS wire rope, it only has to be stretched to take out the slack, don't tighten it up like a piano wire because you're only trying to drive a 10k pot and the second yoke handle. Do you have good bearings on your yoke axles? I used roller bearings, plain bushes may cause excess drag when the wire is tensioned. Roller bearing are really cheap. My first yoke set up had plain bushes which ended up squeaking after a while.

I'm pointing the finger at your yellow rope!

Also see - http://aerosimsolutions.googlepages.com/yokebuild

http://www.mycockpit.org/photopost/s....php?photo=825

Gwyn

[AndyT]

Are your pulleys all the same size?
Are they all mounted the same at the same point with the same hardware and bearings?

[QF6228]

I agree with Gwyn, We have the same setup and found by using the plastic coated steel rope we had slippage, Try using steel cable, It resolved some issues for us.

Damien.

[AndyT]

The question is why do you get slippage in one direction and not the other? The rope could be the problem, but assuming all else is equal something is not balanced on one side. Finding it is where the fun is.

[PaulEMB]

I agree 100% on the SS 2mm wire - I have also used this in my setup, including longer runs of wire around the hyd cylinders, and have no slippage for over 6 months - its a little harder to set up, but I found all I needed in the local hardware store.

I also use bike chain for the top of the yoke/axle connection, linked to the wire partway down the column.

[Trevor Hale]

First off, Thanks to everyone so far fro the help.

The orange rope, may be Nylon, and I will take the suggestion of changing to the ss wire instead.

But the bad news is this. My pulley's do not have any bearings. The have a 1/4" hub and are floating on a 1/4" threaded rod nestled between to nylon nuts. They spin freely however it is somewhat possible that the tension of the wire/string causes friction on the threaded rod.

So what I gather I need to do here is. purchase 6 new pulley's with Bearings on the hub, and replace my clothesline pulley's with them.

Then chance my string to a SS wire rope.

I am ready to rip my hair out on this, but I need to get this sorted before I complete the shell.

Thanks again for all your help.

Oh, and also there is a 1/4" Bolt notched into the top pulley and tightened down, with the string wrapped around it securely, there is no slippage there, but I may need to work on that in a way that is similar to your wire connector hub.

Trev

Hey Guys,

Please tell me what I am doing wrong.

http://www.mycockpit.org/photopost/s...php?photo=2717

http://www.mycockpit.org/photopost/showphoto.php?photo=2715

http://www.mycockpit.org/photopost/s...php?photo=2713

I get good response from Pilot to coPilot with positive movement with every little movement. But when I go Copilot to Pilot, there appears to be some slop and the controls slowly go out of sync.

Please help! I am about to go nuts

Thanks,

Trev

[Tomlin]

Trev,

It sounds like your CURRENT set up is just like the one I attempted to create about 3 years ago and yes, I too was pulling hair out and finally just gave up on it all. Now after Ive discovered MC.org, I know all the places I was doing it wrong! The roller bearings vs. anything else will in and of itself make life much easier. I was also thinking the nylon coated wire would grip better, but evidently not, as demonstrated by all these guys here.

Best of luck!

[Westozy]

Hi Trevor,

Your bottom pulleys should be fine just make sure they have some grease on the axles. I meant your yoke spindle axles should have bearings so the yoke handles rotate very freely without any resistance, this will help a great deal.
I've uploaded this pic to show you how I fitted a small brass electrical connector to my pulley to grip the wire. Aswel as gripping the wire it makes for an easy method of aligning the two yoke handles. Undo the screw, align the handles and tighten it up again. If you do this and use 2mm stainless wire rope, your problem will go away!!!

http://www.mycockpit.org/photopost/s...php?photo=2721

PS Guys, as you see from the pic I have my own lathe and I can make custom pulleys or other turned pieces for any member. Don't be frightened to ask, I'm always looking for beer funds, plus postage of course!

Gwyn

[Trevor Hale]

Thanks Again.

OK, Well that gives me some places to try. I will start with changing the cable, and see if I can add some greese to the pully's. I do not have a lot of resistance on my yokes, but I do have a bit. I will loosen that up, and change my connector on the top of the pulley to match what you have in your picture.

Here is hoping.

Trev