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[Trucker]

hi, all
is there an easy way to confirm that my motor spindles are straight and true, i have one that whilst connected to the prop shaft when rotated by hand (no power connected) it appears lift at a certain point which is a bit puzzling for me, ive contacted the seller and they suggest sending it back but i just wonder if i could confirm any probs


Trucker

[john44]

Hi trucker, what coupling are you using? It could be drilled off centre, motor or prop,
causing a high point, I have Come across that problem.
Is the prop shaft threaded, could be a poor thread,or the shaft could be bent.


Regards
John

[TailUK]

Proper tool for the job would be a Dial Test Indicator.  If you don't have access to a DTI a cheap and cheerful alternative is a ball point pen. Secure the motor and set the tip of the pen just touching the spindle,  make sure both the pen and the motor can't move about. Carefully turn the spindle by hand and watch the gap between the spindle and the pen. Any variation will indicate an out of true spindle.

[Trucker]

guys
I've had a look at the prop shafts, rolled them over a glass sheet and they appear to be fine, the couplings are black UJ, couplings with brass inserts at both ends, I've crossed the affected motor over to the other prop shaft and I get the same, leaning towards the motor being faulty but find it hard to accept.

[john44]

Hi trucker, did you roll the motor shaft over the glass sheet with the brass insert fitted to it?


John

[Trucker]

john
i didnt roll the motors on the glass, just the prop shafts, nothing attached to them, to day ive put the motors on a battery and powered them up, run with a set square up against the spindle and to be honest they look fine, so well puzzled 

[john44]

Hi trucker, was that with the brass part of the couplings fitted to the motor shaft.
E.g. With the square touching the spline of the coupling to check if it runs true.


John

[andyquirot]

Hi all
I have had this prob and the threads on the end of the shaft were no cut center. Fit  the coupling to the shaft and rotate sea if it's centered.
Good luck.
 Regards Andy Q

[chas]

Problems with Hugo style inserts are far from rare. I and many others have encountered them before.

[Detomo]

Hi peeps,


Having an issue with coupling to the prop shaft. When you go forward the motor spins well, as you go back the coupling moves up the prop shaft and then jams and blows a fuze done a few times now doing ones  head in , as this only happens on the starboard shaft. i,am using an action p94 /p102 combo, please any ideas by the it,s on a tug

[Colin Bishop]

The propeller is tightening the connection. You need a locknut on the coupling. There is a bit more to it than that though. Have a read of this article on the Model Boats website which explains it all. The diagrams are all at the end of  it.

https://www.modelboats.co.uk/1270/drivelines/

Colin
 

[mike_victoriabc]

Hello Colin
Thanks for posting the link - good timing as I am tweaking an older twin prop setup put in a Shelley Foss hull that I recently acquired.
Alignment wasn't the best and this information is worth a read!
Thanks, Mike

[Detomo]

cheers guys thanks for the info 

[roycv]

Hi all, I use the Huco brass connections carefully locked onto shafts etc.  But I now use some flexible tubing like neprene cut into a 2 inch length in place of the plastic u/j.  The tubing is 1cm diameter and the centre hole is 5mm dia so the tube wall is 2.5mm diameter.  It is a tight fit onto the brass part of the couplings and a quick high speed run of the motor has it settled.
Virtually no vibration and silence!  I was given a length of this tubing and it is orange in colour otherwise I know no more of its' origin.
Roy
 

[Circlip]

Congratulations Roy, you've re-invented a drive coupling manufactured and sold in the late fifties. Problem we found was it couldn't cope with the torque generated by an ED Racer. This type of coupling DEMANDS perfect alignment of shaft and motor. My personal loathing of Hewies has been well documented on this forum BUT  . . . .


 Regards  Ian.

[Treble]

Mobile Marine Models in Lincoln sell different sizes of this style of " plastic pipe " coupling .