Floating Square End Flexshaft and Thrust Washer?

[Shooter]

Hi guys. Trying to get some feedback/past experience/knowledge, etc...

Has anyone ever ran a floating flexline with a square drive at the strut (exactly like our old K&B outboard motors). It essentially allows the use of a thrust bushing/bearing at the strut without the concern of flex length shrinkage.

Reason I ask is that I've been running very long flexlines lately to shift the weight forward and I think the sideload of the flex line on the stuffing tube (due to prop thrust) is causing issues.

Thanks!

[Fluid]

I would be surprised if a long flex cable was causing "issues" in handling - gas guys run cables between 2 and 3 feet long. As long as you have adequate lube (type and quantity) it should not make a big difference IME anyway. One problem with the square drive is keeping the cable in the boat. A cable saver in front of the stuffing tube would suffice for that, although that adds complexity. Finding the right coupler is a lot harder too. So few FE guys run a square drive that there is little FE experience with them outside of OBs. A collet drive isn't a problem for most folks.




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[Shooter]

That says a a lot. If the gas guys are running 2-3ft, then the 18" I am running shouldn't be a problem.

It definitely wasn't an alignment problem. It was aligned so well that if I loosened the collet screws on the motor shaft, I could spin the prop and it would spin like a top.

Is it possible that I didn't have ENOUGH bend in the stuffing tube? The longer length allowed for an almost straight shot to the strut.

[D&D]

When I ran nitro boats I ran square drives for some 14 years and never had a problem. However, I ran a square nut at the engine with a soldered ferrell which connected with set screws to the prop shaft. Finding a good thrust bearing/washer is very important with this setup, non of the ball bearing types ever worked for me. I used something that looked like a hard plasting washer, it was more than that but I don't remember what it was (got it from Areomarine I believe). Never could find this setup when I tried electric so now I just run the standard shaft setup.

[Shooter]

D&D - I remember those set-ups. I'm pretty sure it was a teflon washer.

Fluid - Regarding your collet comment, the 'floating' square drive would ONLY be at the propshaft end. A collet would still be used at the motor side. The whole idea would be to move the thrust load to the rigid strut, and not the long length of flex where it side loads the stuffing tube ID.

[D&D]

I tried the Teflon, but both my OPS 67 and CMB Grand Prix 90 would just crush them. With a little more thought (they come slow when your over 70) what really worked for me was a set of two metal washers (impregnated with some lubricant) with a hard plastic washer in between. I never did wear out that type of thrust washer.

I see Fluid's comment, but my square drive had the square drive nut at the engine (as previously slated) and the square end of the shaft would float in the square drive nut. And, yes that put all of the pressure at the strut rather than on the engine bearings. Still think it would work today, just couldn't find that type of setup anymore.....