pioneer PL-12D motor issue

if u have the Rifa cap replace it!
i was very surprised to find that in a jap player!

on a second thought mine must have been put together here somewhere in europe to cut shipping costs? wich explains the Rifa capacitor.

yours should have a matsushita cap or something like that. and probably is put together in japan.

lets see! you just have to pull it apart now!
 
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Can you tinker with that motor before investing in a new one?

It looks like the shaft has slipped down, allowing the rotor to contact and erode the motor body. Is there a way to "prop it up" to move the rotor assembly further away from the motor body, ie, by installing a clip washer around the motor shaft if possible?

55460d1211822398-metric-e-clips-eclip.jpg
 
i do love to tinker!

i´ll pull up all the parts tomorrow, the player isnt on the table right this moment, i had a race with some ampifiers a while ago.

thats a "E-clip" ?
 
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Yeah l see what you mean now about the missing metal, not sure what has caused this but slimecity might be on to something.
 
That missing metal might be where they ground material off the rotor at the factory in order to balance it. Balancing the rotor is super critical on a belt drive turntable without a suspension because any motor noise or vibration is going to be transmitted right to the arm and then to your speakers in the form of rumble.
 
That missing metal might be where they ground material off the rotor at the factory in order to balance it. Balancing the rotor is super critical on a belt drive turntable without a suspension because any motor noise or vibration is going to be transmitted right to the arm and then to your speakers in the form of rumble.
Are you sure about that ?
I understand the need for balance, but that missing metal doesn't look ground. More like pitting with bits coming off.
 
1.) The chipping of the edge of the rotor has no bearing on the issue at hand which started the current issue. MOTOR HUM! Fredrik; Have you replaced the rubber motor mount grommets? If not the motor can hang on a metal to metal contact point instead of being isolated by the rubber. Check the mounts for sag or extreme looseness. In both cases replace the mounts with new. Contact Gary @ thevoiceofmusic.com Very good chance he'll have the mounts.

2.) The chipping off of the end piece of the rotor doesn't have anything to do with the operation of the motor except if it gets too bad it can cause an imbalance and the motor will get the shakes like a washing machine of rocks on Spin. Honestly it looks like it's been there since day one either accidently or on purpose to balance the rotor. The rotor is just a series of magnets that are energized during operation and the field rotates
 
yes the "hum" is heard like a pretty loud say 100hz tone in the speakers between songs.
i´ll have a look at the rubber mounts,
 
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well i have the unit back on the bench in pieces.
when holding the motor in my hand and starting it i feel the viblations, its 50Hz (i have a good feel :D) its like a bad transformer!

some pics
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the windings meashure
358Ohm
350Ohm

this looks like a desk fan motor....:idea: lets see what i have in the scrap heap :D
 
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Bathroom fan motor may be the same speed. I pulled an old garrard syncro motor out of a turntable and put in place of fan motor 2 years ago. Damn thing is quieter by 4db (measured). Turns out the bushings in the motor were egged out from lack of lube. (been in there 29 years without lube. Got my $$ worth on that one).

If bathroom fan is same, you can get replacement fan (with motor @ home depot) for about $15.00. You might have to trim shaft to fit.

Check the rubber mounts. They should be pliable not hard. Check side to side movement of shaft in bushings. They look a bit dry. fill the cups with oil and let sit to soak up oil in the felt around the bushings and the sintered brass to soak up oil for a day. Drain off excess after 24 hours and assemble, but reverse top and bottom bushings. The top bushing takes more side pressure, and can egg out the bushing slightly causing vibrations. This may help with the hum.

Larry
 
ther rubber mounts are actually pretty good, the flash+dust make em look wierd.
but there is no way any rubber would isolate the way this motor vibrates! if i switch of it stops vibrating instantly even though the shaft spins for a couple of seconds before it stops.

must be something wrong with the windings?
 
Nothing wrong with the windings. If the windings were bad the speed would be erratic or it wouldn't spin. The bushings are shot or the rotor itself is worn down where it contacts the bushings. When you have an electrical field energized the rotor spins, but with the slop in the bushings, the rotor vibrates side to side as the field changes as the rotor rotates, creating a vibration in the motor which gets picked up in the chassis, as it's more than the mounts can handle. When you shut off the energy the rotor spins down but there is no electrical field to cause it to vibrate side to side. Check the rotor with a small caliper on the shaft where the bushings contact and again at non contact points and see if you can move the shaft side to side in the bushings (it will be very slight if anything).
 
i cant let go of the thought about the fan motor:)
would there be some option to build a dc supply go that route?that opens up a bit in the motor choice department.

just brainstorming here.

yeah i know a sensible dude had bought a replacement on ebay. but im not so sensible:D
 
Shit. You can't swap the bearing housings. The bottom is closed. Don't try to remove the bushings from the housing. You'll just ruin the retainer. The bearing measurements look ok. Grab the rotor and see if it wiggles (side to side or twist's top to bottom) on the shaft. See if you can determine if the rotor is actually parallel with the shaft. I grabbing at straws here.

Bathroom fan motors of this type are always AC. Damn! I forgot you're in Sweden, and no Home Depot. Do you have large home improvement stores or something along that line? Maybe IKEA???
 
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