Ball thrust bearing vs teflon washer

[Alfa Spirit]

Hello guys,
Which one do you use on your fast electric offshore and why, thanks

[befu]

teflon

Good question, I will be watching this thread.

All of my boats use teflon spacers.

1. I can make them on the lathe and I have teflon rounds at work = free!

2. they really do not need any maintenance, one less thing for me to screw up!

3. I never think about ordering them when placing other orders.

so I guess my reasons are I am cheap, lazy and forgetful!

Brian

[m4a1usr]

Not too difficult a question to answer. A metal bearing supports a much greater load then a teflon disk. Your question might be better answered should the thrust load be placed on the motor or the strut? Now thats a question to answer. Yet the answer is simple. Think about it.

John

[Alfa Spirit]

I always installed Ball thrust bearing on my previous boats, using liquid oil after every run. Rust isn' t a problem, may be a high RPM around 35000 is the problem....
Anyway a ball thrust bearing is fantastic, very high efficiency

[Raydee]

Are you taking about using the teflon washer on the motor end or the strut end?

[NativePaul]

At the strut end I guess, without water lubrication PTFE washers will have much higher friction than a ball race, and in the open air inside a boat without water resistance on the balls I don't believe anything can come close to the efficiency of a ball race.

Personally I use the motor bearings with flex shafts and a pair of PTFE washers at the strut for wire drives.

[D&D]

I always ran square drives with teflon washers at the strut, never any pressure on the motor bearings.....

[Alfa Spirit]

Are you taking about using the teflon washer on the motor end or the strut end?

I' m talking about the strut mount like on the picture

[Steven Vaccaro]

On a cable that "floats" like a square drive, you can use teflon at the strut. But in a system where the cable is secured with screws at the motor coupler and soldered into the prop shaft, the load shouldn't be taken at the strut, because the tightening of the flex cable under load will cause binding and drag issues.

[Alfa Spirit]

I replaced PTFE washers by a Ball Thrust Bearing and the result is very good, propeller turns very easily a long time.
If there is no problem with high RPM (35000) that' s ok

[TRUCKPULL]

Alain

The bearing at the strut is only good for, Wire drives or Square drive setups.

NOT Flex shaft drives.

Larry

[Alfa Spirit]

Please, can you explain?

[Steven Vaccaro]

On a cable that "floats" like a square drive, you can use teflon at the strut. But in a system where the cable is secured with screws at the motor coupler and soldered into the prop shaft, the load shouldn't be taken at the strut, because the tightening of the flex cable under load will cause binding and drag issues.

[D&D]

On a cable that "floats" like a square drive, you can use teflon at the strut. But in a system where the cable is secured with screws at the motor coupler and soldered into the prop shaft, the load shouldn't be taken at the strut, because the tightening of the flex cable under load will cause binding and drag issues.

I agree with Steve. However; when running bearings at the motor end you must leave clearance for cable "windup" at the strut or run another bearing/teflon at the strut. Steve - have you seen a square drive nut for a 5mm motor shaft?

[KTM_EXC]

I agree with Steve. However; when running bearings at the motor end you must leave clearance for cable "windup" at the strut or run another bearing/teflon at the strut. Steve - have you seen a square drive nut for a 5mm motor shaft?

Hello to everybody.
That means if I have a flex drive and I use a thrust bearing on the other end (motor) instead of the strut one, it will works properly?
Thanks
Andrea