Rock-Ola 454 Motor Question

[jukeboy]

Hello,
   Can anyone tell me what the Ohm resistance should be on a good carousel (basket) motor (Part# 47699-A) from a Rock-Ola 454 ?
I measured just under 2 Ohms at my motor's connector. I suspect the motor may be bad because the "Mechanism" breaker keeps tripping about 1-2 secs after the motor is energized.

   First, The motor was totally disengaged from the carousel drive gear to remove any mechanical load.
Side note: The disengaged Carousel Basket can be spun freely with just a couple fingers (indicating no binding).
Upon activating the "Scan" switch, the drive gear on the motor turns about 1/4 rotation then trips the Control Panel "Mechanism" breaker.
When I disconnnect/unplug the Carousel motor completely from the circuit, I then can activate the scan switch with no breakers tripping.
I also tried replacing the Play Relay with the same results.
Any suggestions?
Thanks!

[Ron Rich]

Hi,
Did you disassemble that motor-- clean the commutator--use CARDBOARD to clean between segments, saturated with a safety solvent--clean the gear box of "sticky grease" --- oil the motor with 20 wt ND oil -- clean the brushes up --flatten them slightly, or replace them if need--then run it--hopefully that will end your problem. Don't know how one can measure that type motor's resistance ? Ronn Rich

[bele2009]

Just measured mine from a Rockola 474.

5.5 ohms and it draws about 0.7A when tested on a 24VDC supply. The motor and gearbox were just completely cleaned and lubed a few days ago. Hope this may help, your resistance reading seems very low, indicating a shorted commutator and/or rotor.

Eric

[jukeboy]

Hello!
Bele2009: ~2 Ohms seemed a bit low to me also. thank you for checking.

Ron: I'll disassemble & clean-out the old motor/gear box for the experience and cross my fingers. 

Thank you!
Now eveyone go wash your hands.....lol
Stay safe everyone...

[Ron Rich]

Hi,
Well my thinking was it can not be measured with the armature installed, as carbon build-up will cause erroneous readings --I think. The armature can be checked (when clean!) using a "growler"--Most small motor shops have this item--- Ron Rich

[jukeboy]

Hello,
I disassembled the motor and was very surprized to find (2) halfs of a mangled washer on the electrical side of the motor.
The brush side of the motor was filled with dirt/carbon? the commutator was filled solid between a several segments.
I put the armature shaft in my verticle drill press, and as it was spinning, I engaged it with 600 grit emery paper mounted to a perpendicular bracket to ensure even sanding. I didn't
get 100% of all the deep grooves sanded out but I'm hoping it'll be effective enough for my first attempt at this.
I had to use a razor blade to clean out between the segments. then lighly polished the commutator with 1000 grit paper.
After cleaning out the old sticky peanut butter from the gearbox, I coated everything lightly with 20 wt motor oil.
Once everything was cleaned and reassembled, My curiousity peaked so I used a 24VDC 500ma wall adaptor from an old electric desk stapler to perform a quick test of the motor.
Can't wait to reinstall/test it in the juke tommorrow.
Thanks!

[Ron Rich]

Jukeboy,
You don't read, do you--I wrote to use cardboard-- you used a razor--which is a NO, NO, as you can cause shorts in the commutator, with a razor blade-- Hopefully you got "lucky"-- What didja find with the "quick test ?? If it sounded good there, it should work--especially with the "peanut butter" removed ?? Ron Rich

[jukeboy]

Hello!
yes I can read. The cardboard wasn't firm enough to cut through the impacted segment bridges. While powering the motor with the 24vdc wall adaptor the motor runs. Not sure exactly how loud or noisey it's supposed to sound having nothing to reference from, but at least it's clean, lubed & running at this point.
But when I reconnected it to the jukebox (without any mechanical load) the "Mechanism" breaker trips in either Scan or Operation mode. If my measurements are correct, the the motor is pulling a little over 2Amps vs the 0.7Amps Bele2009 mentioned. While reassembling the motor yesterday, I did notice the magnets had some rough spots (Wondering if the broken washer may have played a part?). Can the stator magnets be sanded smooth? or are they coated/insulated because they appear to be unevenly glazed in areas.
Thanks!

[jukeboy]

Hello, just a follow-up. the replacement carousel motor pulled only 0.73 Amps. the carousel motor now works without tripping any control breakers. The juke correctly selected, played and returned about 10-15 selections before the console button selector developed an issue. it won't accept the third numerical button selection. but that'll be another post...thanks!

[Ron Rich]

Hi,
Thanks for the up-date-- I would ASSUME the first motor has some "shortz, in the commutator -- Good luck on the 2nd problem-- Ron Rich