Author Topic: Turntable power - What am i doing wrong?  (Read 166 times)

voxACthirtee

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Turntable power - What am i doing wrong?
« on: August 10, 2019, 08:34:49 PM »
Have to admit, while i can redo the amps and tuners, and finally did a relube on an old Collaro,i'm not that hip on the old turntables.
Trying to get one a couple old stereo gold mag/collaro to work in a Magnavox console. I know the tuner is kicking out AC through the tuntable power socket, but i tried the 2 turntables i have and neither one does anything.Obviously you can only test so much out of the console, though i suppose i can plug in direct AC(through a fuse or something).
So what am i missing here. Do i have 2 worthless turntables? they both spin freely, i cleaned and repacked the bearing on one, and the knobs seemingly actuate ok. Speed knob goes between speeds, etc.
if i pull it out, what do i test?
just need to get one working.

HiFiFun

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Re: Turntable power - What am i doing wrong?
« Reply #1 on: August 10, 2019, 09:02:35 PM »
From your post, it appears you have AC power to the
turntable plug in stage on the chassis.

1. Remove the platter from the record changers,
power them up and observer motor rotor for rotation.

Commonly, old oil/grease hardens and can slow and
even stop the electric motors from turning.

1a. Try to turn the motor rotor by hand to see if
you can move it.
If motor is seized with old lubrication, motor removal and
dis-assembly and cleaning is required.

2. If the motor rotors are turning, the idler wheel and or
drive wheel rubber can harden to a point where there
is no friction coefficient left to grip the platter and the
motor rotor.
Replacement of drive and/or idler wheels then warranted.

3. Less common is that the record changer on/off switch
is broken. (But I just had to service a 1956 Collaro with a
broken switch, so it does happen)
HFF

Bill

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Re: Turntable power - What am i doing wrong?
« Reply #2 on: August 11, 2019, 06:55:44 AM »
I'll add my two cents!  For some reason Collaro changer motors are prone to seize up.  I have had to clean and lube all of mine.  Like HIFI Fun said, remove the platter and check to see if the motor is even turning.  Once done, they will work just fine.

Bill

 

electra225

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Re: Turntable power - What am i doing wrong?
« Reply #3 on: August 11, 2019, 09:56:58 AM »
I'll add my two cents to Bill's two cents.  The upper bearing seems to be the one that seizes more often.  You need to soak those things in lacquer thinner at least overnight to float out all the gunge from the bearing.  Then dry it well, then lube it with turbine oil.  Not three-in-one oil.  You need to use oil that will not turn to glue when it gets hot.  Magnavox would mount the changer above the amplifier in many cases.  The motor is subjected to a lot of external heat, besides what it generates on its own.  Good luck.
I don't need Google.  My wife says she knows everything.

voxACthirtee

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Re: Turntable power - What am i doing wrong?
« Reply #4 on: August 11, 2019, 01:47:46 PM »
Thanks, i didn't think that motors that stayed inside all their life would freeze up.I will try the suggestions and see what i come up with.

voxACthirtee

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Re: Turntable power - What am i doing wrong?
« Reply #5 on: August 12, 2019, 05:39:55 PM »
So out of curiosity, how free should the motors spin? Out of the console, both motors spin, but not super freely. So not locked, but perhaps still in need of refurbing.Also my have issues where the start/reject mechanism is only sort of functioning. The horseshoe switch under the turntable on the one i checked seems to work(i cleaned the contacts) but it may not get actuated correctly at this point.

electra225

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Re: Turntable power - What am i doing wrong?
« Reply #6 on: August 12, 2019, 06:45:42 PM »
There is not a spec for coast time on those motors that I know of.  I'd say if you can spin the shaft with your fingers, then it coasts for five revolutions or more, you should be good.  A better way to tell if they are too stiff is when they are running.  If the bearings are binding, the motor will get too hot to touch.  When they are lubed properly, they don't run all that warm.  This is question is one of those that is hard to answer with specificity. 

The reject issue may be caused by hardened grease.  Try a good cleaning and lubing then check operation.  Is the motor starting?  Or is the motor starting, but the platter is not spinning?  Have you replaced the drive tire and motor mounts? 
I don't need Google.  My wife says she knows everything.

Bill

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Re: Turntable power - What am i doing wrong?
« Reply #7 on: August 12, 2019, 07:56:23 PM »
The motor definitely needs cleaned and lubed.  If it's not spinning fairly free, it's laboring.  If it's laboring, it's loosing power to the idler, and then to the plater.  Is the idler rubber hard as nails?  Is the plater surface, where the idler makes contact, free from dirt, oil, and grease?  All of those play into the workings of the turntable.  Also, like Greg suggested, the mechanical workings of the changer need to be cleaned and lubed.  This is all a pretty standard procedure, when it comes to vintage changers.  Don't get frustrated, we have all been there.

Bill


TC Chris

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Re: Turntable power - What am i doing wrong?
« Reply #8 on: August 12, 2019, 09:06:35 PM »
 just took apart the V-M changer from my orphan console.  On this one, it was the bottom bearing on the motor that was seized up.  In fact, the little bronze part of the bearing pulled out of the housing/lube reservoir when I took it apart.  The upper bearing spins freely, although I added some oil.  The turntable bearing grease was still greasy (the platter would rotate a long time when spun, which surprised me).

So right now that bottom bearing is soaking in lacquer thinner.  I'll dry it and re-lube it and then clean the idler, motor drive surfaces, and platter drive surfaces.

Chris Campbell

voxACthirtee

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Re: Turntable power - What am i doing wrong?
« Reply #9 on: August 13, 2019, 12:35:38 PM »
Yes, i suppose i misspoke there.
The real question should be
"i can TURN the motor, but is it supposed to spin free, because it won't"
Annnnnnd i think i have my answer. They both turn by hand but there's
NO freewheeeling at all in the motor.
Any links to taking them apart and lubing them?
Simplest way to get them going, with the least amount of exotic oilsand esoteric cleansers? I just replaced my transmission, money for such things is non existent.

HiFiFun

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Re: Turntable power - What am i doing wrong?
« Reply #10 on: August 13, 2019, 02:56:46 PM »
Will you post some photos or the model number
of the Collaro record changer ?

There are downloads in this forum for the service
sheets for some Collaro changers.

Yes, the rotor should spin very freely, and they
do after the cleaning and lube.

A good and inexpensive turbine oil for the motor
refurbishment is ZoomSpout, sold at many places.

No special cleaners needed, you can use 91% isopropyl
alcohol. Some use lacquer thinner. I don't use the thinner due
to new formulations being pretty toxic to sentient life.

HFF

TC Chris

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Re: Turntable power - What am i doing wrong?
« Reply #11 on: August 13, 2019, 04:59:01 PM »
Yeah--I cleaned up my motor last night for a total cost of  $0.00.  I had the can of oil and the lacquer thinner.  The only real secret is to draw a diagram of what screws or other pieces are in what locations.  The goal os to get the end caps on the motor, the ones that hold the bearings, off. 

Chris Campbell

voxACthirtee

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Re: Turntable power - What am i doing wrong?
« Reply #12 on: August 16, 2019, 04:55:53 PM »
Thanks for the help. I just had at them and got them cleaned and reassembled.I had the ispropyl here and they were not too gunked up anyways.I had already cleaned and lubed the very top bearing, and the motor wasn't that bad.Came apart and went together pretty easy.
Focusing on the Magnavox F-200 thats the better of the 2.It Spins and turns now. Problem now is the idler wheel.Its mostly round but pretty hard. It makes noise such as to make it unusable.I cleaned the inside of the idler wheel and the shaft- lubed it up and it spins fine and noise free, it makes noise when in contact with the motor spindle. Seems weird that hard rubber would make almost a grinding sound. But i'm pretty sure thats it.Idler wheel spins free and doesn't seem to make noise if i turn it putting pressure on the side while i turn it.Motor spindle spins free and makes no noise if i apply side pressure while its running.
Is it just the hard rubber? can any of those actuating arms underneath the idler arm be rubbing on something? Hard to tell with it installed and the turntable in the console.
I'm most of the way there though


electra225

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Re: Turntable power - What am i doing wrong?
« Reply #13 on: August 16, 2019, 11:05:39 PM »
A drive tire with hard rubber can make noise as well as slip.  If it slips, the changer may not cycle and the speed may not be steady.  It can make a noise that sounds like the platter is rubbing on something.  Gary at VM Enthusiasts can fix you up with a rebuilt drive tire.  You send yours in and he send you a rebuilt one.  Replace the motor mounts while you have the changer out, if you have not already done that.  Good luck.
I don't need Google.  My wife says she knows everything.

voxACthirtee

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Re: Turntable power - What am i doing wrong?
« Reply #14 on: August 17, 2019, 02:06:47 PM »
Thanks, looking up my options they are pricier than i want to invest in this one.Anyone have a decent one to spare? Can trade for something, buy it... will get a measurement, but its a Maggie F-200