Seig C4 Lathe CNC conversion

Just a quick post...has anyone done a CNC conversion on a Seig C4 Lathe? I've found a thread on the zone but not much else. This is my first project at my new job looking at buying a new Lathe and converting the existing Seig C4 lathe to CNC.

If anyone's got any suggestions for a good lathe with a swing over the cross slide of approx 250mm (preferably single phase) DRO and for approx £4,500 I'd be grateful :thumsup: The lathe has to be purchased before the end of the month (funds burning a hole in the accountant's pocket) as it's year end.

I'm guessing for the CNC conversion that a couple of ballscrews, direct couplings, NEMA 23 motors, BOB, PSU and Mach 3 and I'll be on my way. Questions at this stage are how can I control the spindle speed, it's a brushless DC motor so I presume a PWM signal is generated from the electronic speed controller, could I control it from Mach? Could I use the existing leadscrew and just take the gear off and atach the stepper direct? The cross slide lead screw looks like it's going to be interesting. I'll probably take it apart tomorrow and have a look.

Attachment 12025

What power steppers would I need? I was thinking of 2 off Standard 3Nm ones, with 2 x AM882's, UIM2901-5A BOB and PS806-5 PSU. Those components have been chosen just to get it up and running ASAP, yes I know I can shop around and get them cheaper but I'd rather buy as much from one place as I can in this instance.

For the new lathe I want one with a DRO and a swing over the cross slide of 225mm or more. However as it's only for occasional use re-facing couplings and putting in a new circlip groove I don't want that big a machine, plus I'd prefer it as a single phase motor.

All help and guidance is appreciated!