Problem with Wire drive and Thrust bearing

[ezhitz]

Hi
I have been running a wire drive in my LSH hydro and I noticed after about 16 runs the thrust washer has been wearing a groove in the stub shaft.
Is there a better alternative I bought the wire drive from OSE.

Bearing Groove.jpg

[martin]

Can be quite a common problem using thrust bearings on any shaft, I think you will find most using wire drives don't use a thrust bearing of this type. Personally I don't use any thrust bearing whether in using a flex or wire drive.

[ray schrauwen]

What kind of bearings are in your strut? Terry Davis runs wire in his 1/10th scale, no thrust bearings but uses ball bearings in strut.

If you're using lead Teflon in strut, just the slight play at new will cause this.

[ezhitz]

I am running lead Teflon. I'm going to try running it with just the thrust bearing behind the collet.

[ray schrauwen]

That's not a bad idea. The lead Teflon will wear similar to the thrust bearing wear you have because of the force of the wire under tension from the bend.

[ray schrauwen]

And after a little running it will give your prop a different angle of thrust after wear.

[T.S.Davis]

Terry Davis runs wire in his 1/10th scale, no thrust bearings but uses ball bearings in strut.

I've gotten away from that. I was using a .25 od x .125 id bearing with a flange and an extended inner race. Then shimmed up to .187 after the bearing for the prop. Works great but is too fragile. One little bump and the 1/8" part would bend right at the extended race. I wire drive with any kink in it is a mess. Eats everything in it's path. Plus the bearings don't hold up if you run a ton of laps like I do. Tiny little balls in a bearing that small.

Now my wire drives have a traditional sleeve bearing. No where near as smooth but less prone to damage. I still use a thrust bearing but its at the motor. The cheesy Tamiya 5mm bearing works better than the BOCA version with the plastic retainer. We've seen two of those in the last couple weeks melt the retainer at the motor. Makes a mess.

[longballlumber]

I've gotten away from that. I was using a .25 od x .125 id bearing with a flange and an extended inner race. Then shimmed up to .187 after the bearing for the prop. Works great but is too fragile. One little bump and the 1/8" part would bend right at the extended race. I wire drive with any kink in it is a mess. Eats everything in it's path. Plus the bearings down hold up if you run a ton of laps like I do. Tiny little balls in a bearing that small.

Terry, you were using brass tubing to create your stub. Have you ever tried using stainless steel? K&S has the appropriate sizes to make that work. Stainless steel should prevent the bending?

[T.S.Davis]

It's in the trunk of my car right now as I type. Should be better stainless on a brass sleeve bearing.

[T.S.Davis]

I did use stainless .125 on the last bearing setup I built. Still bent at the bearing. It's a week point IMO.

[jwohlt]

I only run a thrust washer at the coupler end against the motor face...you need two papers thickness gap there....not tight against the motor. I think motors these days are much better with screwed in rear bearing plates.