Gearing motor down without gearbox

[Adam Marshall]

I have a 5hp 3.7kw ac motor that runs at 2850rpm but I want the shaft it is to drive to run at around 800/900rpm as gearboxes for this motor are a fortune pulleys are the only option for me I would like to do it through 2 pulleys apposed to just 1. How are the sizes of pulleys calculated? Thank you

 

[WorkshopChris]

Use this calculator to get you the speed you want for your 2nd pulley then use again for the 3rd final one.

https://www.blocklayer.com/pulley-belt.aspx

 

[Adam Marshall]

Thanks workshopchris appreciate that