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VPI Scout - slow speed , help ?

Hi

I've recently purchased a KAB speed strobe which has indicated that my Scout is running very slow (notches moving counter clockwise); over 100 notches in 60 seconds.

I have the newer black belt with unknown time on it; I've cleaned the belt, motor grooves and platter grooves. I get power from a dedicated 15amp plug, through an Audience AR-6 conditioner and stock power cord to the motor. I've tried using different notches on the upgraded 300 rpm motor pulley, with little effect.

I suppose the cheapest experiment is to buy a new belt, and lube the spindle bearing (for which I'll have to purchase oil) and see if that changes things. Short of buying the VPI SDS, are there any other actions which may help here for little money? Perhaps a used Variac would essentially do what the SDS does?

Your constructive feedback is appreciated.

Regards,

Bryn
bshapperd
jazzgene
145 posts
 
That is way off. Do you have the motor positioned properly?

Do you have a test record with say a 3khz tone? Use a frequency counter and check.

If music is in tune, the strobe is defective. I have the KAB and they are usually dead on, though.
bshapperd OP
84 posts
 
Well, I think I've just discovered some major power fluctuations in my 'hood!

With the motor positioned correctly, I tried Elizabeth's trick; I counted 103 1/3rd rotations in 3 minutes. I tried the KAB again and it was reading fast (????)!

My assumption now would be that the power to my home fluctuates greatly throughout the day? We have a new 200 amp panel, new wiring and a dedicated line to the TT. How do I check voltage from the wall socket; can I do this with a multimeter?

B
hifihvn
943 posts
 
Bshappered, your VPI has a synchronous motor I beleive. That means it should sync up with the 60 cycles from an outlet. The 60 cycles is almost always accurate. The voltage will vary a lot in some places, but not the 60 cycles. You could check the outlet voltage with a multimeter. Read the instructions, and be careful. You could also get a P3 Kilowatt meter that just plugs in. Your voltage could be from 114 volts to 126 volts. With that voltage variation, the VPI should hold its speed. Something else must be going on, unless you really have voltage out of the 114-126 volt range. The 60 cycles will keep it right with 114-126 volts. A link for a P3 Kilowatt, that might be sold at your local home center. [http://www.mcmelectronics.com/product/28-10985&CAWELAID=220321019]
hifihvn
943 posts
 
Also, the P3 Kilowatt can be left plugged in, and you could watch the Volts or cycles readout. The cycles most likely will stay between 59.99 to 60.00 cycles. That's fine. If you have lights flickering, bulbs burning out, call your electric company, or electrician to get there quickly. That would be in case they left a loose connection somewhere. Not common, but possible, since new work was just done.
mofimadness's avatar
mofimadness
5,308 posts
 
Make sure the pulley is tight against the motor shaft. It has a set screw I think. Could be that the pulley is slipping a little bit.
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