Flex Shaft Questions

[CraigP]

Fweasel, the true 2-piece system still has a problem. When under high torque, that square drive section doesn't want to float, it can lock up. I think it's safe to say that ANY flex drive application should have some safety distance. The only true prop shaft drive that really is safe from windup is a straight shaft. Then you can be on bearings and collars. Even a wire drive can have changes in overall length.

[R2315]

Got it, Thanks all!

[iop65]

Leaving a gap too big :the solid part of your shaft is not using the whole lenght of the first bushing

[iop65]

If a 4,76mm flex would shrink about 4mm ,this would mean about 71cubic mm of steel is "gone"
Hope hou have enough gap between flex and liner for these 71 cubic mm😉

[CraigP]

Good points... iop, that's probably why my attempt to use a SS tube instead of brass didn't work out. The wall on SS is .028" and on brass it's 0.014". I didn't break anything, but the datalogger showed higher power used while GPS reported slightly lower speed. It got pretty hot hitting the throttle on the stand! I changed it out to brass... Lesson learned.

[Prodrvr]

So you used a tube with double the wall thickness and wonder why it didn't work? Am I correct or did I miss something? Just woke up lol.

[CraigP]

Not wondering anymore! At the time I ordered parts, OSE didn't have any brass. I saw the stainless and talked myself into it. What I actually talked myself into was changing a freakin' strut tube! I'm lucky I didn't break something...

[CraigP]

Forest Gump: "Stupid is as stupid does, can I have another chocolate?"

[Prodrvr]

I have some different stainless tubing on the way to me now. I need to do some experimenting.

[CraigP]

The SS is inherently has less friction, surface hardness matches the steel on the flex better. I think you can get it in thin wall. My experience told me not to mess with those diametric clearances. The "slop" needs to be in there... BTW, not running a liner, that was 1/4 tube to 3/16 flex shaft, all OSE parts...

[Prodrvr]

Yes I agree...needs some slop. I don't run liners either.