Calculating pulley sizes

[elkhuntfever]

I am wanting to make a tumbler to wash my brass. I have an electric motor from a washing machine and I need to figure the pulley sizes needed to get to the proper RPM. The RPM of the motor is 1725, the current pulley on the shaft is 3/4 ". Can I get to 35-45 RPMs with a second pulley and if so, what size diameter does it need to be? For all you geniuses help me out.

[sukivel]

Yes you can, but it would cost more than buying a tumbler and would be huge. Search this forum and you can find detailed, and easy, calculations for finding rpms and pulley sizes. I would post the link but I am on my phone out in the stix...


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[dverna]

It looks like about a 32" pulley to get 40 RPM. Might want to look at a jack shaft. Maybe a surplus gearmotor?

[NineInchNails]

Check out this page: http://www.blocklayer.com/pulley-belteng.aspx

[mdi]

I'm sure a jack shaft would be the solution for this build, but if you use rollers to drive the drum rather than one pulley fixed to the drum you can add that into the ratio (easier to reduce RPM)... https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=pulley+ratios&*

[sukivel]

I'm sure a jack shaft would be the solution for this build, but if you use rollers to drive the drum rather than one pulley fixed to the drum you can add that into the ratio (easier to reduce RPM)... https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=pulley+ratios&*

Yep.
https://uploads.tapatalk-cdn.com/20170401/12842b24afd379f0d90422263c8ffb95.jpghttps://uploads.tapatalk-cdn.com/20170401/e83fd01e831835271929b67c56e2a40e.jpg


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