converting to vfd and 3 phase

[david brum]

Hi all. Here's a queston for those who have converted.

I'm thinking about converting to a vdf on my Jet 1236. Now that I have a really heavy duty stand, it is a pretty smooth operating lathe. I would like to get rid of the Reeves drive and get lower speeds though. It looks like 2-3 hundred bucks will do it.

I'm wondering about what kind of horsepower the motor needs to be. I'm clear that I need an inverter duty 3 phase motor. My question is whether I need more hp than what I currently have? In other words, will I lose hp by going with the vdf? The current 110v motor is 3/4 hp. I'm not really looking for more hp, but don't want to end up with less. I was thinking of a 1 hp 3 phase motor. Sound reasonable?

[Dennis Ford]

You should be very satisified with one HP on that lathe, it will have plenty of power. Be sure to get a motor with the same or slower nominal speed as the existing motor ie; if you have an 1800 rpm motor now, get an 1800 rpm motor. A 1200 rpm motor would be better but not worth the extra cost unless you find a special deal. With a VFD, you should be able to both slow down the motor or speed up the motor.

[david brum]

Thanks for the input Dennis. I'm not looking to make a silk purse out of this lathe, but I would like to make it more versatile. I'll post pictures when I eventually finish the project.