Rockola 440 Gripper and Magazine Motor Blowing Fuses
Hey Everyone,
I seem to keep blowing the "1.6 28VDC Mech" fuse within seconds when the magazine motor or gripper motor-runs. Because I don't have anymore 1.6A fuses I have been using 1.5A ones. I realize that this would be more prone to blowing, but there has to be something wrong here for it to go that quickly. Would the motors be causing this? How can I check to see if the motors are okay? When I turn the motors manually via the little knob on the bottom of them, they turn easily and do not seem gummed up. Any help would be greatly appreciated. Thanks, Robert |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Robert, all I needed was "Rock-Ola" and "gripper motor" -they are
notorious for developing shorted armature turns. From the early 1950's models, right on through the later 80's. If it is blowing quickly, that is the cause. The only other possible cause is that the cam switches are faulty and causing the motor to overtravel and jam. That will be obvious when you turn the motor shaft. Rob/NYC |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
On Jan 16, 9:18*pm, Rob in NYC wrote:
Robert, all I needed was "Rock-Ola" and "gripper motor" *-they are notorious for developing shorted armature turns. *From the early 1950's models, right on through the later 80's. If it is blowing quickly, that is the cause. The only other possible cause is that the cam switches are faulty and causing the motor to overtravel and jam. *That will be obvious when you turn the motor shaft. Rob/NYC Hi Rob. Thanks so much for the reply! Is there a way to fix the motors? I tested the cam switches and they seemed okay, and I also aligned them according to the manual. I can always replace them to be safe. Robert |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Robert, motors can be rewound, while that might be the most reliable
route, it may be cheaper to locate a known-good replacement via one of the ad's in Always Jukin http://www.alwaysjukin.com/ D/L a sample issue and look over the classifieds -the same sellers are there every month. As for the microswitches, if the motor isn't overtravelling and jamming at either end of it's travel the switches are not the problem. If you have a meter capable of measuring amps you might hook it up in series with the fuse, but I'am pretty sure you have the classic problem of excessive current drain from shorted armature turns. Rob/NYC |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Rob in NYC wrote:
Robert, motors can be rewound, while that might be the most reliable route, it may be cheaper to locate a known-good replacement via one of the ad's in Always Jukin http://www.alwaysjukin.com/ D/L a sample issue and look over the classifieds -the same sellers are there every month. As for the microswitches, if the motor isn't overtravelling and jamming at either end of it's travel the switches are not the problem. If you have a meter capable of measuring amps you might hook it up in series with the fuse, but I'am pretty sure you have the classic problem of excessive current drain from shorted armature turns. Rob/NYC The gripper assembly may be gummed up too. This will cause the motor to draw more current than normal. Turning the gripper motor shaft with your fingers should operate the gripper bow through the entire cycle - picking up and replacing records - without feeling like it is jamming up. The gripper arm should feel slightly loose when resting, and the record pin should feel snappy when it is picking up the record (at rest is is solid). The gripper arm should drop when released not go slowly down (indicating gummed up oil/grease). Info on taking the assembly apart is he http://flippers.com/Rockola-tips.html John :-#)# -- (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." |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Thanks for the advice Rob.
I'll take a look at the ads and see if I can find the them. In the meantume, I'm going to try taking them apart and clean them out and see what that does. I've read that people have had success with doing that. Either motor, gripper or magazine blow the fuse. It's just kind of odd that BOTH motors could fail at the same time. Robert On Jan 17, 4:25*am, Rob in NYC wrote: Robert, motors can be rewound, while that might be the most reliable route, it may be cheaper to locate a known-good replacement via one of the ad's in Always Jukinhttp://www.alwaysjukin.com/* D/L a sample issue and look over the classifieds -the same sellers are there every month. As for the microswitches, if the motor isn't overtravelling and jamming at either end of it's travel the switches are not the problem. If you have a meter capable of measuring amps you might hook it up in series with the fuse, but I'am pretty sure you have the classic problem of excessive current drain from shorted armature turns. Rob/NYC |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Thanks John,
I cleaned the outside of the mechanism but have no idea as to what it looks like inside. I'll take a look at that as well but I would think that if the motor is easy to turn using the armature knob it wouldn't be gummed up. Robert The gripper assembly may be gummed up too. This will cause the motor to draw more current than normal. Turning the gripper motor shaft with your fingers should operate the gripper bow through the entire cycle - picking up and replacing records - without feeling like it is jamming up. The gripper arm should feel slightly loose when resting, and the record pin should feel snappy when it is picking up the record (at rest is is solid). The gripper arm should drop when released not go slowly down (indicating gummed up oil/grease). Info on taking the assembly apart is he http://flippers.com/Rockola-tips.html John :-#)# -- * * (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."- Hide quoted text - - Show quoted text - |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Robert, while having two defective motors may seem odd. The fact is
that they were both made by the same maker and frankly, cheaply, in keeping with Rock-Ola's policy of simple machines that didn't cost a lot. The circuit involved is very simple: unfiltered DC feeding two brush motors one at a time. If you can access a meter to actually read the amps being consumed that will show what is going on. It wouldn't hurt to open the motors and clean out all the carbon from the brushes and use a small stiff brush to 'comb' out carbon from the individual commutator segments (the steps the brushes ride on) but I doubt that will make any significant difference. Almost every R-O phono that I found had a larger fuse in the motor supply and the reason as I repeatedly found was failing motors. Sorry to be the bearer of bad news but, there are plenty of motors around. Rob/NYC I'll take a look at the ads and see if I can find the them. *In the meantume, I'm going to try taking them apart and clean them out and see what that does. *I've read that people have had success with doing that. *Either motor, gripper or magazine blow the fuse. It's just kind of odd that BOTH motors could fail at the same time. Robert |
Rockola 440 Gripper and Magazine Motor Blowing Fuses
Thanks for the advice Rob.
I called one of the ads in the classified section of Always Jukin', my wife's boss gave me a copy. (Thanks again, that was a great idea) Ironically, the the guy I called about purchasing two motors, suggested that I try a few things before spending the money for the motors. 1. Running the motors while disconnected from each of their respective gear mechanisms to see what would happen without a load. I tried it and it still blew the fuse. 2. Clean the motor out: So far I took the Gripper motor apart and it was filthy inside. I cleaned it out but need to do the same with the carousel motor. Once I do that I'll try it again and see what happens. I certainly appreciate your advice. But I would like to see if there is any way that I may be able to fix this first before having to purchase another set of motors. On one hand this is frustrating, but on the other, I am learning A LOT about the way these things work and it's really quite interesting :) Robert On Jan 18, 2:06*am, Rob in NYC wrote: Robert, while having two defective motors may seem odd. The fact is that they were both made by the same maker and frankly, cheaply, in keeping with Rock-Ola's policy of simple machines that didn't cost a lot. The circuit involved is very simple: unfiltered DC feeding two brush motors one at a time. *If you can access a meter to actually read the amps being consumed that will show what is going on. It wouldn't hurt to open the motors and clean out all the carbon from the brushes and use a small stiff brush to 'comb' out carbon from the individual commutator segments (the steps the brushes ride on) but I doubt that will make any significant difference. Almost every R-O phono that I found had a larger fuse in the motor supply and the reason as I repeatedly found was failing motors. Sorry to be the bearer of bad news but, there are plenty of motors around. Rob/NYC I'll take a look at the ads and see if I can find the them. *In the meantume, I'm going to try taking them apart and clean them out and see what that does. *I've read that people have had success with doing that. *Either motor, gripper or magazine blow the fuse. It's just kind of odd that BOTH motors could fail at the same time. Robert |
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 |
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