Sensor less vector vs closed loop vector

[Ross77]

So how is the performance with the original lead screws Clive? can you zero out the backlash in the cross slide?

Thanks A_Camera, yeah I think I will invest in the cable and brake, they are out of stock now so will have to see how long it takes them to restock before I make my final decision. Having looked at the PID in more detail I think you a right and it is more suited to the slower response of temperature control rather than machine spindle control. How does the jog control work? is it like a servo motor for indexing?

Thanks M_C. the motor I was planning to use is an inverter duty 4 pole so should be good from 150 to 3000rpm. 2.2kw specs are:

For Variable Speed use:-
Part Time Output when Inverter powered is...
7.30Nm - 2.2kW ( 2.95HP) x 2880 RPM at 100 Hz
14.59Nm - 2.2kW ( 2.95HP) x 1440 RPM at 50 Hz
14.59Nm -1.1kW ( 1.47HP) x 720 RPM at 25 Hz
14.59Nm - 0.22kW (0.29HP) x 144 RPM at 5 Hz
Continuous Output when Inverter powered is...
10.4Nm -2.2kW ( 2.95HP) x 2016 RPM at 70 Hz
14.59Nm -2.2kW ( 2.95HP) x 1440 RPM at 50 Hz
12.40Nm - 0.94kW ( 1.25HP) x 720 RPM at 25 Hz
7.30Nm - 0.11kW (0.15HP) x 144 RPM at 5 Hz

The lathe is only 125mm centre so not much capacity for large stock and low rpm. I was more looking for indexing at low speed. I will check the cutter forces though.

[Clive S]

So how is the performance with the original lead screws Clive? can you zero out the backlash in the cross slide?

I don't zero out any backlash because I find that on the lathe you (or I) always back off from X at the end of the cut run and then then any backlash is taken up when you start the next cut. If that makes sense. The conversion I did was from this guy http://www.jeffree.co.uk/modelengineering.html