Help diagnosing thorens td-160 issue

[cschaub]

I have a 1st gen Thorens TD-160 without the transit locking screws. The wow/flutter is bugging me. RPM says I am running at 33.64 with wow/flutter of .30. New Thorens belt for a few months. Really clean unit, but I am noticing a wobble when the motor runs ... posted video with and without belt on. Is this wobble indicative of a bent shaft or something else? The motor runs quiet unless the belt is off and then it knocks a lot. Ok, videos attached, thanks for any advice!

Without belt
https://www.dropbox.com/s/6s1vuf0k40gptbs/Video Jun 16, 8 09 42 AM.mov?dl=0

With belt
https://www.dropbox.com/s/0u83d5p7k6wvjxp/Video Jun 16, 8 11 10 AM.mov?dl=0

 

[Solist]

It should not wobble like that. I would look for possible fixes or try to get a replacement part.

 

[grantly]

It should not wobble like that. I would look for possible fixes or try to get a replacement part.

Agreed. That wobble should not happen.

My first thought would be to purchase a motor spindle support kit (available on the auction site), but that wobble is rather severe. I don’t know if it would help. I’m guessing the shaft/spindle is bent, which means you may need a new motor.

 

[gadget73]

I notice this one doesn't have the stopper screw. Must be an early one. Later ones had an extra long screw as one of the motor mounting screws to prevent the platter from being able to bang into the motor and bending it. Fair bet this is what happened here. The fix is probably a new motor unless you know a guy who is able to fix fussy stuff like this. Its not impossible that very careful application of pressure in the right spot can straighten that spindle but done wrong it'll break or make it worse.

 

[bobins08]

It sure looks like the motor spindle. I would take the pulley apart, you need a very small Allen wrench to do it ... this site will help:

http://www.theanalogdept.com/td160maintenance.htm

Take it apart and inspect it. Make sure the spindle is perpendicular to the horizontal top plate. Verify if the spindle is bent.

Could be simple like the motor installation - as in not aligned with top plate. Or maybe the pulley was put together incorrectly?

Hopefully it’s not a bent motor spindle.

 

[tnsilver]

The motor spindle is bent so bad I can hear the motor wobbling as the spindle presses too tight against the upper bushings. Nothing you can do but replace that motor - or get that spindle complete with the rotor to a magician machinist.

 

[muovimies]

That's a bad wobble, but personally i would try to straighten it - nothing to lose at that point... With some luck and little oil, you could perhaps get the motor back to shape where you can at least use it until you get a replacement. I had a (admittedly way less severe) wobble I was able to fix pretty well by myself. After very carefully banging at a wooden block held against the spindle for what seemed like forever, during 3 different sessions, I finally got it in quite nice shape. I measured it and it's down to fraction of a mm now - something like 0.2mm or 1/125 inches - you can still see it when you look straight from the top, but it's way past the point where I could hear any kind of symptoms from it (at the beginning the wow in platter speed was quite noticeable).

It's a bit of an oversight in the design of the early TD-160... the combination of heavy outer platter and very wobbly suspension means the platter is pretty much bound to hit the motor spindle at some point during the life cycle of the table. All it takes is someone ignorant lifting up the table and moving it to a different location ONCE, and if they are not very very careful, it's quite likely the outer platter hits the spindle hard enough to bend it. I'm sure they had cautions in the owners manual to never move the table with the outer platter in place... but seems like it doesn't work quite as well as an actual metal piece protecting the spindle.

 

[ZebraBlvd]

I've tried straightening motor shafts on a couple of Thorens platter motors (if that is the problem). Came to the conclusion it was not worth the time and trouble. Plus, I never did get them perfectly straight. My $0.02, get another good motor and pulley. One of the cheapest investments you'll make for a great performing table.