Rockola 440 Gripper and Magazine Motor Blowing Fuses

On 1/20/2012 4:12 AM, g0pkh wrote:
robert;690440 Wrote:
Hi John,

Okay I'll give it a shot and post back.


Robert



On Jan 19, 6:43*pm, John Robertson wrote:-
robert wrote:-
Hi Pete,-
-
I took the gripper motor apart, cleaned it out polished up the
communicator and thought that would solve the problem but when I
connected it and ran the machine it still blew a fuse *The carousel
motor is beyond my repair ability so I think I'm going to have to get
a replacement anyway.-
-
I don't see the capacitors on these particular motors. *I have a
Rockola 483 that I plan on restoring (if I ever get this one done!)
that does have the caps on the motor.-
-
The kicker is that these two motors are going to cost more than I paid
for the machine *lol.-

Before you replace the motors try running a thin flat blade between
each
commutator on the armature. I have had motors that have too much carbon
jammed in between each commutator conductor leading to the appearance
of
a shorted motor.

Do not use a blade like an Exacto, you need something thin and flat
ended to scrape the bottom of the grove between each conductor.
Polishing the faces of the commutator won't help that much.

John :-#)#




-
Robert-
-
On Jan 19, 5:10 am, g0pkh wrote:-
Hi Robert--
--
A while back I restored my first jukebox, A Rock-Ola 474 machine.--
--
I too had problems with both of these motors.--
--
I was really lucky and managed to find two brand new old stock
armatures
for them. And after a complete rebuild and regrease, they now run
brilliantly.--
--
They are 28V DC Motors. I tested mine by connecting them to a Bench
Variable Power Supply unit, and wound up the voltage slowly while
monitoring the current. Mine were both taking in excess of 2A which is
the limit of my PSU. By the time I got to 20V DC--
--
I found that after the rebuild the motors would run off load and
consume
in the area of 500mA, while at the full 28V.--
--
I didn't have a problem with shorted turns on mine. The problem I had
was that the commutators (sections where the brushes connect the
armature) had a deep groove worn in them, plus the grease in the
gearboxes had congealed, and needed to be cleaned out completely, then
fully regreased.--
--
Also with the armatures and brushes removed, you may like to check the
suppression capacitors (tubular devices connected across the motors)
for
a short circuit.--
--
These capacitors are installed to reduce motor noise. Strangely the
motors in my machine did not have these fitted.--
--
Hope this info helps--
--
Pete--
--
--
g0pkh--

--
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Hi Robert

If you do as John suggests. That may sort the armatures out.

That's odd, I've done it at least 50 times and never shorted out the
armature. What it does is removes the shorts between the commutators.
I use a dental cleaning tool to scrape out the crud.