Man, if only I were. As you know, I replaced the thrust plate. When I put it back together, I could hear a very soft scraping sound when I put my ear next to the spindle. So, I kept dumping oil in drop by drop. I'd place a little at the top of the bearing, and run the thing for a few hours until it dripped down, then I'd repeat. It soaked up tons of oil, and began behaving much better. The noise ceased and the motor runs cooler (it was slightly warm feeling and smelling before, now it is hardly warm, I had given it a couple of drops too). The spindle started floating 1/4" above it's resting place when I pulled the platter off (and slowing poping back up if I pushed it down). All signs pointed to a much wetter bearing than ever before.
I then purchased a new belt. I purchased it from www.turntablebasics.com who lists the belt as 34 cm. This is longer than the replacement belt I put on a few years back. The old one seemed way too tight, so again, I thought I was on the right track.
So, I brought it back upstairs and the speed is no better. When I listen to anything with sustained notes, I hear the pitch wobble considerably. It makes one feel uneasy to hear music with it. The motor mounts are fine. What do I do now?
pj
I then purchased a new belt. I purchased it from www.turntablebasics.com who lists the belt as 34 cm. This is longer than the replacement belt I put on a few years back. The old one seemed way too tight, so again, I thought I was on the right track.
So, I brought it back upstairs and the speed is no better. When I listen to anything with sustained notes, I hear the pitch wobble considerably. It makes one feel uneasy to hear music with it. The motor mounts are fine. What do I do now?
pj
PJ
I had the same experience with the floating platter.
My conclusion was that there was some sort of hydraulic action going on, so I removed some of the oil in the cap, leaving enough to lubricate the Delrin but eliminate the floating effect.
However, I don't know if this would contribute to any of the speed inconsisties that you are experiencing.
Sounds more like a motor problem...
I did run across a forum with lengthy discussions and theory on motor speed variations but do not remember seeing any conclusions.
Sounds like a good time for some advice from the Electric Gypsy...
Gypsy, are you out there???
I had the same experience with the floating platter.
My conclusion was that there was some sort of hydraulic action going on, so I removed some of the oil in the cap, leaving enough to lubricate the Delrin but eliminate the floating effect.
However, I don't know if this would contribute to any of the speed inconsisties that you are experiencing.
Sounds more like a motor problem...
I did run across a forum with lengthy discussions and theory on motor speed variations but do not remember seeing any conclusions.
Sounds like a good time for some advice from the Electric Gypsy...
Gypsy, are you out there???
El Gippo reports in
I'd take the motor out, take it to a gas station, and blast it out with compressed air ( tire machine )
That will get all the dust out of there, which might be the issue
Spin the motor by hand at the pulley and feel if there's any looseness or binding; don't worry if there's some North-South movement in the spindle shaft, that's OK
It's East-West movement you don't want
You can do the same thing with the platter with the belt removed; check for binding by spinning backwards and forwards by hand
**Remove the belt, get the platter so it's not quite level; spin it fast and leave it to come to a stop by itself. If its not binding, or sticking somewhere, the platter will come to a halt and then spin backwards a 1/3 turn and stop. That's what it *should* do
If it's hanging up somewhere by friction; it won't do the 1/3 turn backspin and you'll have to look for where it's sticking**
My Pioneer has a speed change mechanism that is a lever that pushes against the belt to lift it from 33 to 45; make sure that's not pressing against the belt while the platter is spinning, that will also cause speed inconsistency because the belt will be dragging against the change lever
I would drop the motor off to a Tech and get it hooked up to an oscilloscope to see how it measures and if any of the windings have failed; if there's no issues there then that eliminates the motor and it will be something else
Cleanout the bearing well and spindle with parts cleaner and check that there isn't any garbage in there, check for irregular wear or scuffing; I had a turntable once had been, I suspect, dropped and landed on its platter edge, this had ever-so-slightly
bent the spindle at the top of the bearing well and it was rubbing there, spinning the platter very slowly by hand I could detect the binding and an inspection of the bearing well and spindle showed where
I checked the runout of the platter by using a dial gauge on the edge and this showed the platter was out of true 0.2mm, too small to detect by sight, but large enough that it showed there's been damage
Whatever your turntable is doing, it will be easy enough to run down
I'd start with cleaning and checking the motor
Gypsies go Electric
I'd take the motor out, take it to a gas station, and blast it out with compressed air ( tire machine )
That will get all the dust out of there, which might be the issue
Spin the motor by hand at the pulley and feel if there's any looseness or binding; don't worry if there's some North-South movement in the spindle shaft, that's OK
It's East-West movement you don't want
You can do the same thing with the platter with the belt removed; check for binding by spinning backwards and forwards by hand
**Remove the belt, get the platter so it's not quite level; spin it fast and leave it to come to a stop by itself. If its not binding, or sticking somewhere, the platter will come to a halt and then spin backwards a 1/3 turn and stop. That's what it *should* do
If it's hanging up somewhere by friction; it won't do the 1/3 turn backspin and you'll have to look for where it's sticking**
My Pioneer has a speed change mechanism that is a lever that pushes against the belt to lift it from 33 to 45; make sure that's not pressing against the belt while the platter is spinning, that will also cause speed inconsistency because the belt will be dragging against the change lever
I would drop the motor off to a Tech and get it hooked up to an oscilloscope to see how it measures and if any of the windings have failed; if there's no issues there then that eliminates the motor and it will be something else
Cleanout the bearing well and spindle with parts cleaner and check that there isn't any garbage in there, check for irregular wear or scuffing; I had a turntable once had been, I suspect, dropped and landed on its platter edge, this had ever-so-slightly
bent the spindle at the top of the bearing well and it was rubbing there, spinning the platter very slowly by hand I could detect the binding and an inspection of the bearing well and spindle showed where
I checked the runout of the platter by using a dial gauge on the edge and this showed the platter was out of true 0.2mm, too small to detect by sight, but large enough that it showed there's been damage
Whatever your turntable is doing, it will be easy enough to run down
I'd start with cleaning and checking the motor
Gypsies go Electric
That's what I've been thining. The MMF2 the tone arm came off of and an original AR I had have such tiny motors, (and less substantial, not as smooth bearings) that it hardly seems like a little bearing issue could create such a problem. I'm not writing the possibility off entirely, but I think the next step is to take the motor to shop. I hope it isn't too expensive.
pj
pj
Speed change thingy
Thickness ( more appropriately, "tallness" ) of the turntable belt is critical as this affects the speed change mechanism if an incorrect belt is used
You can *see* the belt riding against the speed change lever when the turntable is running, + it shouldn't do that
You can *slightly* bend the speed change lever if you are confident that will make the necessary clearance
You can also completely remove the speed change thingy and move the belt up and down by hand to change from 33 to 45
Gypsies rule the Electromagnetic Domain
****************************************************
Thickness ( more appropriately, "tallness" ) of the turntable belt is critical as this affects the speed change mechanism if an incorrect belt is used
You can *see* the belt riding against the speed change lever when the turntable is running, + it shouldn't do that
You can *slightly* bend the speed change lever if you are confident that will make the necessary clearance
You can also completely remove the speed change thingy and move the belt up and down by hand to change from 33 to 45
Gypsies rule the Electromagnetic Domain
****************************************************
Both belts I've used ride right over the fat part of the capstan (brass pulley thing on the motor). Neither touches the speed change lever. Does anyone know the OEM belt dimensions? Like I said earler, I've recieved two different sizes from two different vendors.
Dave, that cap on the bottom does come off. Take the platter off first, and the spindle will drop out the bottom of the bearing. If your thrust plate is shot, have somebody make a new one. Clean everything up and oil it. Use some silicon or something around the edge of the cap to keep oil from leaking out. I then kept dropping oil at the top spindle/bearing juncture for a few days to really get the bearing wet again. If any folks have better methods, feel free to jump in.
I haven't taken the motor out yet. It looks clean as can be. However, the oil tubes appear to be all full of junk. Any chance a dry bearing at the bottom of the motor is causing my problem? I'll try and find some new vinyl tubes.
pj
Dave, that cap on the bottom does come off. Take the platter off first, and the spindle will drop out the bottom of the bearing. If your thrust plate is shot, have somebody make a new one. Clean everything up and oil it. Use some silicon or something around the edge of the cap to keep oil from leaking out. I then kept dropping oil at the top spindle/bearing juncture for a few days to really get the bearing wet again. If any folks have better methods, feel free to jump in.
I haven't taken the motor out yet. It looks clean as can be. However, the oil tubes appear to be all full of junk. Any chance a dry bearing at the bottom of the motor is causing my problem? I'll try and find some new vinyl tubes.
pj
Dave,
I don't think glueing is a good option. Getting someone to make a new one shouldn't be a big deal. I thought about having the shop make a few, but I've seen so little talk of this table that I was afraid no one could use them. If I don't get my problems sorted out, I may have a parts unit soon. I hope it doesn't come to that.
pj
I don't think glueing is a good option. Getting someone to make a new one shouldn't be a big deal. I thought about having the shop make a few, but I've seen so little talk of this table that I was afraid no one could use them. If I don't get my problems sorted out, I may have a parts unit soon. I hope it doesn't come to that.
pj
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