Model Boat Mayhem

Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: Trucker on May 10, 2018, 07:47:01 pm

Title: motor spindle
Post by: Trucker on May 10, 2018, 07:47:01 pm

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

Title: Re: motor spindle
Post by: john44 on May 10, 2018, 09:23:49 pm

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

Title: Re: motor spindle
Post by: TailUK on May 11, 2018, 11:48:00 am

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.

Title: Re: motor spindle
Post by: Trucker on May 11, 2018, 08:23:54 pm

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.

Title: Re: motor spindle
Post by: john44 on May 11, 2018, 09:53:07 pm

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


John

Title: Re: motor spindle
Post by: Trucker on May 12, 2018, 06:31:33 pm

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  {:-{

Title: Re: motor spindle
Post by: john44 on May 12, 2018, 08:37:20 pm

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

Title: Re: motor spindle
Post by: andyquirot on May 13, 2018, 10:28:39 pm

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

Title: Re: motor spindle
Post by: chas on May 13, 2018, 10:35:05 pm

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