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Old January 21st 12, 10:08 PM posted to alt.collecting.juke-boxes
robert
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Posts: 20
Default Rockola 440 Gripper and Magazine Motor Blowing Fuses

Hi Pete,

I may have sent this to you directly so my apologies if there is a
duplicate.

I only have a DMM, which gets me through most things. Anything more
involved I usually send out.

Robert


On Jan 20, 5:42*pm, g0pkh wrote:
robert;690451 Wrote:



Hi Pete,


Thanks for the link.


If cleaning between the communicator bars solves the issue of any
shorts, will the motor still work with the worn brushes or will I have
to replace them before I can test the motor?


Robert.


On Jan 20, 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---
-
--
* * (Please post followups or tech enquiries to the newsgroup)
* John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
* Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
* * * * * * * * * * *www.flippers.com
* * * *"Old pinballers never die, they just flip out."--


Hi Robert


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


However you will still need two sets of brushes. You can buy them from
a
chap in Germany here.


http://www.jukebox-world.de/


He does brush sets for most of these motors.


Pete


P.S


Tell about paying more than what the machine is worth LOL
That is the problem with restoring these girls.


It seems likely that yours both had the motors replaced for duff
before
it was scrapped.


--
g0pkh-


Hi Robert

If the brushes are not too badly worn, then yes the motor will still
work.

However, I saw a picture of one of your motors which showed one brush as
completely worn to the end.

if you have two reasonable brushes out of the remaining 3 (out of both
motors of course) then give it a try.

You would be wise when testing to use an ammeter in series with the
motor to monitor the current (10A range if possible).

How are you for test gear ?
Once you get into this sort of repair you start to need the extra gear
unfortunately. A variable bench power supply is invaluable here.

Pete

--
g0pkh


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