Build a lathe with Acorn

[Leo Voisine]

I have an old Craftsman Atlas lathe and I am thinking about converting it to a CNC lathe.

Currently the speed is adjusted with belt and pulley but I want to drive the spindle with a VFD and motor

The VFD's look to be around $100 or so dollars.

I don't know if I can use the motor that is on the lathe now?

What do I need to know about VFD's and motors to make the spindle run from Acorn.

[suntravel]

If you want to skip the belt and pulley reduction you will need a motor with 2-3 times the power rating to keep low speed torque.

Uwe

[tblough]

And a VFD that supports sensorless vector control, also for low end torque. You can try to use your existing motor, but you may burn it out quickly. VFD rated motors have special insulation on the windings to handle the higher frequencies used. Sometimes non-VFD rated motors work fine, other times, the windings short out. No harm in trying to use it.

[Leo Voisine]

As I am learning motr about it I am thinking that the existing motor is old and likely not built to handle the VFD. I will not use it.
It is 1/2 hp.

I am thinking a 1-1/2 hp 3450 RPM motor with a reduction ratio to the spindle.

[tblough]

Baldor makes a great line of inverter rated motors with speed ratings of 0-6000rpm.