Re: [ARSCLIST] Repairing (or purchasing) a Uher

[Scott Phillips <scottp@xxxxxxxxx>]

I'm pretty sure you can use the 3202/3402 motors without a problem. 

Grinding the shafts is difficult as I recall because the ceramic shaft
tends to expand while grinding them, or at least when they were in
production I was aware that watching QC on the shafts was really
important. That said, the required standards for production on the
motors was higher than you really need, I'd think. 

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Richard L. Hess
Sent: Wednesday, June 14, 2006 3:27 PM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] Repairing (or purchasing) a Uher

At 03:48 PM 6/14/2006, Scott Phillips wrote:
>I'm not completely positive, but I don't think you'll ever get the 
>APR's to run much slower than you have. They have brushed capstan 
>motors, and they will tend to 'cog' at slow speeds because of it. Might

>I suggest trying having the shaft on an APR capstan motor ground down 
>to a smaller diameter so the motor RPM stays higher...just a thought. 
>AMP services might be able to do it, among others....
>

Thank you, Scott,

I agree...I don't think I'll have anyone touch the capstan shaft on the
APR-16 <smile>...but getting an APR-5000 motor turned down would be
do-able.

I need to check as the capstans on the 3202 and 3402 are also turned
down, and perhaps a 3202 capstan motor could be used on a 5000.

Since the A807 is also a DC servo motor, I wonder how it would run at
15/16 and 15/32.

Does anyone who has a slow speed Revox happen to know what the capstan
diameter is? I'm wondering if that is turned down from the standard
3.75/7.5 A77 capstan. If it isn't that would bode well for the A77/B77
and A810 to be running at slower speeds. All these use the Studer AC
servo motor. I wonder what its real lower limit is.

I really get frustrated maintaining machines that are used 1-2 times per
year. It's a lose-lose situation. That's why I try modifying my main
machines to handle the outliers.

The modified A810 would conceivable have a divide-by-8 switch so 3.75
would become 15/32, 7.5 would be 15/16 and 15 would be 1-7/8. That would
be very interesting. EQ can be best handled post in the PC, I think.

Cheers,

Richard


Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
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