Pulley ratios

[cooper1203]

hi all, I have had to replace the pulley on the motor spindle as its whats commonly known as uf. the outside od of the pulley was the same but the minor one is slightly smaller (20 thou aprox) than the original one (original to me) but the smaller pulley is 3/8" smaller. this will obviously make the lathe run slower question is with speed of work how accurate does it have to be. is 50 rpm or even 100 going to make a difference

 

[RaisedByWolves]

With a belt change lathe the speeds are “good enough” but never optimal when it leaves the factory.

Gear head lathes are a little better, but short of a decent variable speed machine you’re left with what you’re given.

Don’t sweat it.