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Pulley Wobble - How Much is Too Much?
#1
I notice my motor pulley wobbles slightly.  It is not constant; it will be straight for 3-4 seconds, then will wobble a bit, then go back.  My brain imagines wow and flutter.  How much wobble is too much?
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#2
Have you checked the tightness of the grub screws that hold the pulley to the motor shaft?
Classic Signature SE, Fatboy Gimbal 12, Grado Reference3, HW40 Feet, SDS, PS Audio Stellar Phono, PrimaLuna ProLogue Premium preamp, PrimaLuna EVO 300 amp, PS Audio DirectStream P12 Power Plant, Iconoclast, Audience, Grover, Shunyata cables, SRA & Symposium platforms
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#3
I had that problem as well. I  was only tightening one grab screw because the 300 RPM pulley had only one grub screw in my dual motor flywheel assembly.  On my other turntable the HR-X the 300 rpm wobbled so badly it turned to because I was only tightening one grub screw. When I discovered there were 2 I tightened them both and problem solved. Hope this helps.
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#4
930turbo, when did VPI start making their pulleys with only 2-set screws? That’s a basic engineering no-no. Radial symmetry is achieved by using a three set screw design.

bhjazz, no wobble is acceptable.
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#5
No wobble acceptable: exactly what I expected to hear.  I have the three-set-screw pulley, so will snug screws until it is correct.  I thought they were pretty close but clearly they are not.

Thanks, guys.  I appreciate the help.

EDIT:  Could not get this unit wobble-free, so went back to the start.  Removed pulley and then brass collar.  Propped a magnifier up to view the motor shaft up close to see if it is part of the issue, and it turns out that it is.  Wobble wobble.  Had to read the warranty bits but it appears I have some options here, which is good.  Will contact them soon.

Will probably also drop my original motor back in there tomorrow to see what that one looks like up close, although I do not remember any problems with that one.
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#6
(04-28-2022, 02:04 AM)Brf Wrote: 930turbo, when did VPI start making their pulleys with only 2-set screws?  That’s a basic engineering no-no.  Radial symmetry is achieved by using a three set screw design.

bhjazz, no wobble is acceptable.

Not 930 turbo, but my pulley on my HW-19 has two set screws. The motor dates from 2012, but the pulley may be older. I can't remember if I got a new pulley when I had the motor replaced then.
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#7
For fun, linking to a video I had to send to Nidec/Hurst regarding the (likely defective) motor they sent.  Enjoy!

https://www.dropbox.com/s/0lz67zlvkjlo5sw/00001.MTS?dl=0

(I hope I don't have to eat $99)
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#8
(04-28-2022, 02:04 AM)IBrf Wrote: 930turbo, when did VPI start making their pulleys with only 2-set screws?  That’s a basic engineering no-no.  Radial symmetry is achieved by using a three set screw design.

bhjazz, no wobble is acceptable.
That I don't know, Brf.  All I know was my HR-X which I acquired in 2015 already had 2 grub screws . My TNT 6 w/c I had since 2011-12 had only 1 grub screw in its 300 RPM pulley
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