INSIDE A THORENS TD160 MOTOR

[patrick s]

Hi i was just wondering if someone could offer help opening up a thorens td160 motor in need of a repair. After reading the thread below i have some questions

https://audiokarma.org/forums/index.php?threads/inside-the-thorens-td-16x-motor.829672/

From what i understand from that thread, to repair the thorens motor i need to open up the motor and clean the bushings on both housing covers and insert washers. I have a few questions

1. What do i clean the bushing with
2. Where do i insert the washers
3. How do i determine how thick the washers need to be
4. Further explanation with regard re- assembly on position of the coils and how to align?? them



Im a bit of a novice but i do have manual dexterity but i just dont understand the jargon and technical terminology used in the posts. If someone could explain with labelled pics that would be great!!

Thanks.

 

[tnsilver]

Make sure you can't fix this with an anti-knock kit first. Opening up the motor is a risk.

1. What do i clean the bushing with

- turpentine, paint thinner, lighter fluid, any solvent that won't eat your skin. Don't extract the bushings. Leave each in it's half housing case.

2. Where do i insert the washers

- on the rotor shaft

3. How do i determine how thick the washers need to be

Find out. Thick enough to stop the knocking, thin enough not to impede the rotor or god forbid, bind it.

4. Further explanation with regard re- assembly on position of the coils and how to align?? them

Don't align the coils - align the rotor. On close up, make sure the rotor spins as free as it can, while tightening up.

These are the bushings and some washers to play with:

This is the elected candidate in place:

I think there's pretty good images of the rest of it, including the closeup of the housing in my thread.

 

[gadget73]

I tend to use a sharpie to make marks on parts so I can re-orient them the same when putting stuff back together. Never fooled with my 160's motor so I don't know if its even possible to get things clocked wrong tho. Mine is the 120vac type, not the low voltage one in the thread. It runs and doesn't knock so I've just been leaving it alone.


a mention about the 3 in 1, you want the 3 in 1 electric motor oil in the blue can, not the stuff in the red can.

 

[patrick s]

Hey thanks so much!! So more questions

1. do i install another washer on the other end of the rotor shaft too, yes??
2. What do u mean by "aligning the rotor" how does one do this???
3. How do i know how thick the washer has to be to stop knocking - what parts should i be measuring to determine the thickness of the washer???

First i think i should have explained what my motor symptoms are

1. Sometimes the motor spins in the wrong direction on powering up. I have to "power off" and "power on" on to correct it
2. Sometimes knocks sometimes doesnt - motor thrust kit doesnt help
3. If i have no belt on, the motor is silent apart from a faint hum that i need to be right up close to hear ie my ear over the spindle
4. If i have a belt on it makes a louder hum with occasional grinding noise i dont have to be right over the spindle to hear

Cheers

 

[patrick s]

What brand electric motor oil - can i just use singer sewing machine oil??

 

[tnsilver]

Sometimes the motor spins in the wrong direction on powering up. I have to "power off" and "power on" on to correct it

Like I mentioned in my thread, opening up the motor is a last resort move. It's risky, especially if you're inexperienced with electric motors. All the symptoms you describe are consistent with external factors. Spinning in the wrong direction is a text book tell tale sign of a phase shift capacitor gone rogue and excessive vibrations that cause an audible disturbance are typically an escalation of the same issue rooted at the capacitor. Those motors are extremely robust for as long as they're fed voltage in their accepted range. Make sure you try to resolve this in all possible ways before proceeding to fiddling with the motor innards.

Sometimes knocks sometimes doesnt - motor thrust kit doesnt help

That's odd. Given the knock is caused by a minute wear at the bottom bushing at the contact surface with the rotor, It's very strange for an anti-knock kit, which can raise the rotor shaft by a whole lot more than is missing, can't fix it. Where did you get that kit? Are you sure you installed it correctly? It needs to be firmly glued to the bottom of the motor to work right.

If i have no belt on, the motor is silent apart from a faint hum that i need to be right up close to hear ie my ear over the spindle

Sounds like vibrations due to bad phasing across the windings. My guess (again) is it's related to the phase shift capacitor. It's a couple of bucks worth of a fix. Look it up. It's been dealt with a million times here.

If i have a belt on it makes a louder hum with occasional grinding noise i dont have to be right over the spindle

It's very important to correctly identify the source of that grinding noise especially whether or not the grinding noise is coming from the clutch's action. That clutch doesn't appreciate a too short belt. If it's the motor that grinds, it's an entirely different story and an overhaul might be due under the initial disclaimer.

FWIW aligning the rotor means that when you close up the two halves of the housing case, the rotor has to be smack in the middle, meaning both of the shaft ends are centered between the top and bottom bushings.

If you draw an imaginary perpendicular (to the housing case joint) line between the center of the bushings - it becomes the vertical axis of the rotor and agrees with the shaft.

How do i know how thick the washer has to be to stop knocking - what parts should i be measuring to determine the thickness of the washer???

If you install a washer and close up the housing for testing (no screws), you can try to jiggle the motor shaft up and down. If you can't - you got rid of the knocking but now you have to make sure you haven't locked the rotor too tight, so close it up with just a couple of screws and makes sure the rotor spins free. You could use a caliper to measure how far the rotor shaft can be pushed up. That distance is pretty much the desired washer's width minus some fractions of a millimeter for tolerance.

 

[patrick s]

Thanks!!!!! That is soooo much clearer - i fully understand what is required to do now. I needed the idiots guide to motor repair lol. Yes i will replace the cap first!!!! Please read my other thread if u can.....has a lot to do with that...

By the way my thrust bearing kit was a DIY effort - ie 4mm ball bearing resting on a grub screw in a 5mm T nut - held in place with super glue. Ive since removed it because it made no difference to noise levels. If i pushed up the motor shaft with my thumb when motor is running it doesnt make any difference to noise levels either.

So to explain in more detail WHEN the motor decides its going to knock on that particular day it will knock and it will keep knocking until i turn it off. It usually knocks when its spinning in the opposite direction or if i have just removed the belt after spinning vinyl. BUT when i turn the motor on and it doesnt knock it will stay that way and not knock for as long as it stays on ie i think the knock is influenced by position of motor or load on pulley.

Now that you have got the concepts thru my head the motor repair sounds like a relatively simple procedure. So what risk could be involved and at what point could a novice like me stuff it up what should i be wary of if i attempt this???

 

[DavidTT]

Great thread for those of us who may need this info for a Thorens motor some day!

 

[gadget73]

What brand electric motor oil - can i just use singer sewing machine oil??

yes.

Sounds like vibrations due to bad phasing across the windings. My guess (again) is it's related to the phase shift capacitor. It's a couple of bucks worth of a fix. Look it up. It's been dealt with a million times here.

a bad phase shift cap would also explain why it runs in reverse sometimes.

 

[ehoove]

What brand electric motor oil - can i just use singer sewing machine oil??

Just make sure it does not have paraffin in it. I use 3 in 1 Electric Motor oil.
Regards,
Jim

 

[patrick s]

You can only use your thumb (or, for that matter, a 4mm ball) as far as the rim of the housing. When the motor is knocking the shaft can actually go deeper than that. Observe what happens when you pull up on the pulley. Look at the bottom. Only then you'd see how far deep the shaft really goes.

Well if i have the table running upside down the spindle does not sit flush with the motor housing case its a tad maybe less than 1mm below. Yes my motor does get REALLY hot to the touch after its been running for a while - you cant hold onto it for too long put it that way. Thank u Thank u Thank u. Did i say Thank u???

Just make sure it does not have paraffin in it. I use 3 in 1 Electric Motor oil.
Regards,
Jim

Brilliant!!!

Great thread for those of us who may need this info for a Thorens motor some day!

Hell yes!!! They are 40 -50 year old motors they are going to need TLC for sure!!!!!! I see lots of info out there but this is the only place where i could find useful advice on how to repair the motor not just lube it!!!!!!

 

[johnhoef]

Hello, everyone,
Thought I would share my experience with this TD160. A customer brought me this unit with a complaint of a hopping ton arm. Yes, you heard me right - the tone arm actually hops up and down! I didn't believe it until I actually saw it. The cause? A bent motor shaft. So, how to fix this. Do I dare grab a crescent wrench, and try to bend the shaft straight? That force may damage the motor bearings. Do I dismantle the motor and try this? I doubt the bent shaft will slide out of the bearing. Will I be able to get it perfectly straight? I will probably end up replacing the motor, and if so, may as well try this, since I have nothing to lose. Any ideas?

 

[tothmes]

Thought I would share my experience with this TD160. A customer brought me this unit with a complaint of a hopping ton arm. Yes, you heard me right - the tone arm actually hops up and down! I didn't believe it until I actually saw it. The cause? A bent motor shaft. So, how to fix this. Do I dare grab a crescent wrench, and try to bend the shaft straight? That force may damage the motor bearings. Do I dismantle the motor and try this? I doubt the bent shaft will slide out of the bearing. Will I be able to get it perfectly straight? I will probably end up replacing the motor, and if so, may as well try this, since I have nothing to lose. Any ideas?

Sorry, don't have time to repeat myself, but I have written a bit on this before here: https://audiokarma.org/forums/index...150-td150-mkii-or-td160.976399/#post-15169608

It should be doable. Alec at VE doesn' agree with me on the dial indicator thingy, he recommends using a pencil instad for marking out the wobble, and he recommends using a hammer instead of your thumbs.

 

[KentTeffeteller]

What brand electric motor oil - can i just use singer sewing machine oil??

Singer Sewing Machine oil is just fine. 20w machine oil in essence. Good for turntable use.

 

[gadget73]

many ways to mark the high spots in a shaft, a pencil or other fixed whatsit works the same as a dial indicator. All depends what tools you have in your box. I have indicators so I'd probably use that. I'd probably also chuck it in my lathe since that has a clampy device perfectly suited to hold round things, and mounting an indicator on that is also quite easy.

 

[tothmes]

I'd probably also chuck it in my lathe since that has a clampy device perfectly suited to hold round things, and mounting an indicator on that is also quite easy.

A precision lathe could come in handy indeed. The precision of it might be a problem, since one wouldn't want to add any further error of the lathe's to the one of the spindle.

 

[tothmes]

...to the measurement.

 

[johnhoef]

Thanks for the ideas. Checking the cost of these motors...$300!!
I don't have a lathe, but I do have a drill press. I can put the motor shaft in there, and select the lowest speed, which is probably too fast. Or, I can clamp my variable speed hand drill to the table.

 

[tothmes]

I don't have a lathe, but I do have a drill press. I can put the motor shaft in there, and select the lowest speed, which is probably too fast. Or, I can clamp my variable speed hand drill to the table.

I think you'll find that anything connected to the motor spindle while measuring will cause a much larger sideways wobble than what the motor has to begin with. That's why I made my simple hand "knob/tool" for turning the spindle by hand.

 

[gadget73]

A precision lathe could come in handy indeed. The precision of it might be a problem, since one wouldn't want to add any further error of the lathe's to the one of the spindle.

I was thinking just using it as a fixture with the spindle locked and just rotating the motor shaft to find the high spot. at that point the spindle precision doesn't matter.