[JohnR]

I've had my TT on the shelf for a while and really need to tackle the remaining issues with getting it going properly. Is there a way to know what the "correct" tension for a belt is? Last I tried, just moving the motor pod resulted in a significant speed variation. I'm hoping that someone could provide some information on what diagnostic information I might need to provide to determine the problem - belt, motor, or operator error...    Thanks

[chester_audio]

If you have a strobe and disc, you might try watching that while you move the motor. Find the motor position that gives the highest speed. That should fix the belt tension. Then adjust the speed accordingly with the stylus playing in the groove.

[JohnR]

Find the motor position that gives the highest speed.

Thank you, I'll try that.

[Ericus Rex]

There are some tables without electronic speed adjustment that are designed to be adjusted using belt tension.  Not too long ago I saw an Acoustic Solid Royal Small and this was the case ($4,000 table too!).  This leads me to believe that the tension on the belt is not critical.  If you have electronic speed control I'd put the belt as loose as possible and still have it work without slipping.  From working with old machinery (jeweler's lathes, to be exact) I know that very high belt tension pulls the spindles to one side of the bearing and results in an oil-less joint at that point and speeds up wear.  If your table does not have elec speed control then the proper tension would be where ever you reach proper speed.

[Wayner]

As belts age, they tend to relax. This condition may cause slippage at start-up and may be slipping during play, resulting in some speed flutter. However, some tables, like old AR-XAs required the belt to be powdered with talc, to make them slip on purpose, to help the underpowered motor at start-up.

A belt that is too tight will actually act kind of like a string on an instrument and as Ericus Rex stated, will have adverse affects on the platter and bearing. This condition has happened to me with a new belt on my Empire as it was the incorrect length and put too much tension into the mix. The clue here was that the motor assembly ended up tipping towards the platter and made the belt ride incorrectly on the drive pulley.

A properly tensioned belt should be somewhere between these 2 conditions.

Hope this helps.

Wayner

[chester_audio]

Usually, not always , using the highest speed method does result in a rather lose fit for those drive systems that plan on a certain amount of slip. An overly tight belt usually doesn't play very long because the belt will walk off. On my table, once I find the max speed through belt tension, if I make the tension tighter the speed slows down. If I make the tension looser from this point, the speed also slows down. I suspect this may happen on the AR with the talc.

It is certainly dependent. Belt material also has a lot to do with this, and how the belt interacts with the platter and motor pulley, so the method I described doesn't work for all belt drives. It won't work on Basis motors, for example, and that is an example of a drive system where belt tension within reason doesn't have any impact on speed. In any case, this method will tell you which kind of belt drive you have, and what you may or may not be able to do about speed control. Short of manufacturers recommendations, it is a place to start.

[BaMorin]

Usually, not always , using the highest speed method does result in a rather lose fit for those drive systems that plan on a certain amount of slip. An overly tight belt usually doesn't play very long because the belt will walk off. On my table, once I find the max speed through belt tension, if I make the tension tighter the speed slows down. If I make the tension looser from this point, the speed also slows down. I suspect this may happen on the AR with the talc.

It is certainly dependent. Belt material also has a lot to do with this, and how the belt interacts with the platter and motor pulley, so the method I described doesn't work for all belt drives. It won't work on Basis motors, for example, and that is an example of a drive system where belt tension within reason doesn't have any impact on speed. In any case, this method will tell you which kind of belt drive you have, and what you may or may not be able to do about speed control. Short of manufacturers recommendations, it is a place to start.

Every "tight" AR belt I have causes the platter to run slow. Every slightly wider AR belt I have causes the platter to run slow. Every thicker AR belt I have causes the platter to run slow. Every slightly hard compound AR belt I have causes the platter to run slow.

[chester_audio]

Now, THAT is sensitive. Sounds like it needs the Goldilocks touch. Not too much, not too little, but just the right amount of slip.

[Wayner]

AR owners know what has to be done, the machine will remind the listener if he has failed in some regard to belts, talc and even clean pulleys and sub-platter drive rims. Good to keep things clean.

I guess you have to learn to get a feel for the right things. The first good step is following the manufacturer's instructions.

Wayner 

[JohnR]

Well, I've made some progress... the belt tension is a lot looser than I had it before. I still get some wow now and then. I get the impression that it's normal for speed to be hyper-sensitive to belt tension? I guess I don't quite follow this. That doesn't indicate an issue with the motor or power supply?

Also, is there a reasonably inexpensive gadget that will measure speed accurately?

[Ericus Rex]

I just got a turntable that I KNOW is speed stable and I still get some 'wow' every now and then.  When I hear it, the first thing I look for is if the cartridge is riding left and right in the groove, i.e. is it tracking grooves that aren't exactly concentric to the spindle.  Most times, this is the reason I'm getting the wow.  There are those few times when I get it and don't see the cartridge rocking sideways.  I have to attribute that to the cutting of the vinyl.  The weird thing is that sometimes I'll turn that same record over and play the other side and there are no problems at all with the opposite side of the record.  Bizarre!

[orthobiz]

I've had my TT on the shelf for a while and really need to tackle the remaining issues with getting it going properly. 

Did you say what TT you are using?

Paul

[JohnR]

"Using" might be optimistic up till now! It's an Origin Live Aurora. (The older version, I think it was updated at some point.)

[JohnR]

[orthobiz]

Cool! I'll bet the belt falls off sometimes when you are first messing with it!

Paul

[JohnR]

Well, yes, that's how I know it's too loose... 

I'm getting stuck into this collection. Oh man.

[bside123]

Here are two examples of belt tension leading to improper timing and speed:


This belt is too tight... too much tension.


This belt is too loose... not enough tension.

[JohnR]

Something's not right here (and I don't mean that last picture!) Every now and then the speed just drops. It's a DC motor - are these typically sensitive to wall supply voltage? I'm wondering, as I'm on the end of a long line and the neighbours do love their electric ovens and heaters (coming into winter here).

[TheChairGuy]

John,

You might want to email, or even call, Mark Baker of Origin Live with your issue.

Well regulated DC should minimize the inherent 'timing' issues of belt drive...so what you are going thru seems to be an aberration.

He was very good to work with some 2 years ago when i had issues with my OL Illustrious MK II arm.  I didn't sense a hard sell from him (as a marketing/sales person I tend to see this coming fast), just good diagnosis and sensible recommendations to fix.

Ciao, John

[orthobiz]

BTW in the topic title...
I think "hep" is a James Brownism for " help"
 

Paul