Is my 1257's motor dying?

A few months back, whenever I would start my 1257, I noticed that the strobe would come on, but the platter would just sit there and I'd have to start it spinning with my finger. Other times it would start up real slow. Thinking the caps in the control circuit were bad, I replaced them a few weeks ago.

Last night, I turned on the TT, and when the platter wouldn't spin, I pushed it, and nothing happened. I took off the platter and belt and turned it on, and the pulley wouldn't spin until I turned the power off and on like ten times. Trying to spin the pulley with my fingers is very difficult.

I lubed the motor in December 2006... the first oil (a couple of drops of Valvoline 10W-30) it got since new in 1980, but the motor pulley still didn't spin freely afterwards. When the platter does spin, the motor feels quite strong. But when the TT shuts off, the platter comes to an immediate halt. The motor itself feels very hot after running it for a half-hour or so.

Am I looking at replacing the motor with another SM-100?

IMHO, it seems like a bad contact or connection. First if you have a voltmeter you can measure the current that goes to motor.
BTW, does it happens in 33rpm's and 45's ?

Yes, the current and voltage are fine, and it does happen in both speeds. I'm wondering if the bearings aren't ruined, because the pulley is very hard to turn. Sometimes it feels like the motor is struggling to start. Maybe I should try lubing the motor again?

This post has been edited by OvenMaster on October 14, 2007 10:00 am

I'm not sure about TT motors, but a lot of tiny motors have small bronze bushings that sit in a housing with a felt packing that is saturated with a thin lubricant the can last for years. If they fill with dust or just run out, they can drag. You can take the bearing ends off, wash them, and saturate the felts again with something like 3-in-one, of WD-40. I use a Liquid Wrench aerosol. 10-30 is pretty thick oil for a small motor.

I have a dead TT around here - I'll take a look at the motor.

That's a very good idea.

Okay, I'll give that a try as soon as I can, probably tomorrow evening.
Larry? There's no rush on that motor, kind sir. I'm going to see what another lube job will do, if anything. If that doesn't help, I'll be looking at a bunch of options:
* another used motor ($)
* sending the motor out for rebuild ($$)
* another 1257 for parts ($-$$$)
* another 1257 ($$-$$$)
* a cheap 1218/1219/1228/1229/1249/1264 ($$$)
* looking at a new TT that's not a multiplay model, but that's my last resort ($$$$$)

Okay. I just couldn't leave well enough alone; when I have a puzzle that I have to solve, I can't rest until it's finished.

3-in-One did the trick. I took the entire motor apart with the help of a 1268 service manual, and the motor bearings were bone dry and tight. A few drops of 3-in-One, a minute of spinning the rotor by hand and I saw and felt immediately that it spun much easier. I put everything back together and the motor starts right up without any hesitation at all now.

The only reason I'd used 10W-30 last December was because I'd read it on another audio forum. Well, it didn't last even a year with that. How long it lasts with THIS lightweight oil (a day? a week? longer?) is another story, so I'll just have to wait and see.

Thanks again.

This post has been edited by OvenMaster on October 14, 2007 11:55 pm

cool, i wonder how regular bearing grease would work?

Aw, hell! I have some in the basement! I used it on my homebrew white guide replacement, but it never occurred to me to try it on the motor. Seems way thicker than even 10W-30 Valvoline, though.

Scott, if this 3-in-One doesn't last a long time, I'll give it a try the next time I've got the motor apart.

Just how often do you have to oil a TT motor, anyway?

This post has been edited by OvenMaster on October 15, 2007 07:18 am

I know what you mean...
Glad you make it.

I use a product called FP-10, it is a gun lubricant that I have found to be very good for other uses, some of the benefits include being impervious to temperature, it will also clean some of the gunk out of bearings as it is being used. A lot of people use sewing machine oil for their turntables. This is a relatively new product as compared to sewing machine oil. As you are now aware proper lubrication is extremly important and can have drastic effects on proper turntable speed as well.

This is a lnk to their website http://www.mpc-home.com/products-military-fp10.php, I used to be able to buy it locally but recently ordered a new bottle off the internet. I does go a long way but I keep finding new uses for it.

Jim

This post has been edited by Jim Eck on October 15, 2007 09:19 am

Seems that Dual recommended two years as the interval for a lube job with normal use. Jeez! I never oiled anything at all between 1980 and 2006! I'm surprised I didn't destroy the platter or motor bearings in all those years. What a PITA to have to disassemble the entire motor to do this. Sheesh.
1200 series lube guide link
Weird... it also says to use 10W-30 motor oil for the motor (as well as the platter). I did and got trouble within a year. I like your offering, Jim. Seems better than 3-in-One/sewing machine oil.

This post has been edited by OvenMaster on October 16, 2007 11:19 pm

Seems that Dual recommended two years as the interval for a lube job with normal use. Jeez! I never oiled anything at all between 1980 and 2006!...

Seems that Dual recommended two years as the interval for a lube job with normal use. Jeez! I never oiled anything at all between 1980 and 2006! I'm surprised I didn't destroy the platter or motor bearings in all those years. What a PITA to have to disassemble the entire motor to do this. Sheesh.
1200 series lube guide link
Weird... it also says to use 10W-30 motor oil for the motor (as well as the platter). I did and got trouble within a year. I like your offering, Jim. Seems better than 3-in-One/sewing machine oil.

The US military recomends it, I'm surprised we cam buy it without Larry's help. With the military involved it might cost as much as a Pentagon toilet seat.

Jim