Ariston RD 50hz pulley dimensions

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14-11-2019, 00:26
shonan21

Ariston RD 50hz pulley dimensions

Hi everyone, as I mentioned in my intro I have a 60hz RD90 I want to convert to 50hz/100v for use in the Tokyo area, without spending too much. I sold off my old RB250 a while back and will need to get a new arm as well, so something like an Origin Live DC upgrade is beyond my budget.

I haven’t had any luck finding a 50hz Ariston pulley so far and have seen mixed things about a Linn being suitable. Plus Linn pulleys seem to be available only with motor. Regas run a much smaller sub-platter, so I know that’s not an option.

Could anyone with an Ariston RD check the diameter of their 50hz pulley? I believe they all use the same size sub-platter. My calculations predict around 21.6mm for 33rpm, is that correct?
14-11-2019, 01:19
shonan21

Sorry, think my notes were wrong, 21.9mm for 33.33?

Sorry, think my notes were wrong, 21.9mm for 33.33 at 50hz/250rpm?

Quote:

Originally Posted by shonan21

Hi everyone, as I mentioned in my intro I have a 60hz RD90 I want to convert to 50hz/100v for use in the Tokyo area, without spending too much. I sold off my old RB250 a while back and will need to get a new arm as well, so something like an Origin Live DC upgrade is beyond my budget.

I haven’t had any luck finding a 50hz Ariston pulley so far and have seen mixed things about a Linn being suitable. Plus Linn pulleys seem to be available only with motor. Regas run a much smaller sub-platter, so I know that’s not an option.

Could anyone with an Ariston RD check the diameter of their 50hz pulley? I believe they all use the same size sub-platter. My calculations predict around 21.6mm for 33rpm, is that correct?
14-11-2019, 14:14
willbewill

Measured the one from RD80, measured on crown and either side

Crown 29.34 (28.78)
Crown 21.52 (20.77)
15-11-2019, 22:19
shonan21

Interesting! Thank you for checking! The RD80 has a flat belt, right?
15-11-2019, 23:02
willbewill

Quote:

Originally Posted by shonan21

Interesting! Thank you for checking! The RD80 has a flat belt, right?

Yes a flat belt, although my RD40 has a square one.
16-11-2019, 04:12
shonan21

Quote:

Originally Posted by willbewill

Yes a flat belt, although my RD40 has a square one.

I see, thanks. My current 60hz RD90 pulley is the square type.

I’m thinking I may need to look into getting a new pulley machined here in Japan, in which case a typical flat pulley design sounds like the way to go.
21-11-2019, 19:34
Smegger68

It's worth experimenting with wrapping your existing pulley with something like Kapton tape. Use a strobe to check the speed and add as many layers as required to slow the platter down by the needed amount. Kapton is a good choice as it will lay even and grip the belt properly, whilst being thin enough to add a precise thickness.
22-11-2019, 10:02
shonan21

Thanks for the tape recommendation. I thought about trying something like that, but it’s the square belt pulley, which makes it challenging. Might try anyway if I can find some really narrow kapton tape or something similar. But I have a feeling the belt will end up spinning off if it doesn’t have the v-profile pulley. Maybe a flat Ariston belt will work though.