question about electric motor starting up on lathe

[ryansuperbee]

Hey guys. I have a medium sized lathe and I was wandering if there is an easy way to make the motor come on "slowly" intstead of just taking off really fast. I'm looking for a way to make my lathe motor come on more like how a bench grinder comes on, nice and slow. Is there some type of resistor or capacitor that would make this happen? Thanks!

[Al_The_Man]

You did not say what kind of motor you have, if single phase induction motor then there is not much out there, you can go with a 3 phase motor and a VFD.
Al.

[Geof]

The only reason a grinder spins up nice and slow is that it is a small motor turning a large rotating mass with a lot of rotational inertia being spun up to 3400 rpm in direct drive. The lathe is often a bigger motor spinning the rotating mass up to a much lower speed through a reduction belt drive.

Al's suggestion for a VFD will work but will be a lot of dollars and a possibly less expensive option may be to get a small centrifugal clutch on the motor pulley. This allows the motor to come up to speed faster but the lathe takes a bit longer.