Music Hall drive belt won't track straight

[sombunya]

I have a Music Hall MMF9.1. I bought it used but with low mileage I presume and it looked great.

The drive belt keeps flipping 1/4 of a turn. I've tried moving the motor around to change the tension, roll the belt another quarter turn thinking maybe it will find its own "sweet spot", and even tried setting everything on a sheet of glass thinking that maybe the motor was slightly cocked but it continues to happen. I'll also give the platter a push to start it (a practice I learned using a TD 166 for a few years) but it soon rols over 1/4 of the way.

The folks at Music Hall were nice enough to send me a new belt, gratis, but it still occurs. I doubt that it even poses an issue but I can't imagine it was engineered to allow this.

I'll start the belt straight and it runs very steady. But after 10-15 seconds it rolls over and I can see it vibrating. Any advice is greatly appreciated.

 

[treitz3]

Hello, sombunya. Interesting issue you have there. Please allow me to ask a question simply to eliminate this as a possible cause. Have you taken all of the shipping screws out from the chassis? I'm not familiar with your level of experience with this TT so forgive me if this question is way to basic, border lining offensive, but I can't think of any other reason the belt would flip. Could you post a picture of your TT with the platter removed and the belt [untouched] after it flips please?

Tom

 

[sombunya]

There's no question too basic that I can be asked. I've done plenty of lame things in my time.

I'll check into that, and post pics soon, for sure.

I appreciate your response.

 

[sombunya]

The transit screws are out and the TT is perfectly level, according to the built-in level. The platter spins very freely without the belt on.

It's somewhat difficult for me to capture a photo of it but let me try:



As you know, there are three little pucks on the bottom of the drive motor. They look okay, the same height. I did experiment by tilting the motor in towards the TT a bit by shimming up the two outside pucks about .030". The unit has been running for about 5 minutes now and the belt has not turned.

I removed the shim and the belt flipped. I re-inserted the shim and the belt is running straight. I suppose I just walked myself through to answer.

So it looks like the centerline of the drive motor is not parallel to the centerline of the platter, I think.

Sorry if I've bored anyone here. Any comments are always welcomed.

 

[sombunya]

One more thing; the belt wasn't free after all. $45, that includes shipping.

When I explained what was going on to a guy at Music Hall, here's what I got:

"Clearly there is the slightest variance in the shelf, the feet, or the motor pulley causing the belt to twist. As you say, you have solved the problem with the shims. You've come up with a good solution, best to leave it alone.

Cheers,
l "

I guess I will have to live with it.

 

[treitz3]

If you don't mind me asking, was this a new TT?

Tom

 

[sombunya]

If you don't mind me asking, was this a new TT?

Tom

No. It was sold to me as "nearly new" and certainly looked the part, right down to the original packaging, etc. Not a mark on it.

The addage Buyer Beware certainly rings true.