Thank you once again. I did watch those videos and seen his work (I am one of his followers) but... There is no way I want to compete with Simpson36 or anyone else. I am too old for competitions, just want to have fun and learn something new. My goal is just that. In the end, if I like it, or see a huge need of a real lathe then I'll buy one. To be honest, I don't think my machine will ever be able to be as good as a cheap 800-1000 USD cheap Chinese micro lathe, even though, mine might well end up being more expensive in the end.

Regarding the needed torque, honestly, I don't know what I need. All I know is that the current stepper is labelled 1.8Nm, but that's always holding torque. I don't know what the real torque is at 2280 rpm, which is what the rpm is now when the chuck runs at 380 rpm, but it is enough to drill in steel. This weekend I did some turning tests, which was a disaster but not mainly because of the stepper, but because of the extremely weak cross slide I was trying to use. Anyway, I could only turn soft plastic...

I understand that your link was just an example, not a direct recommendation, but it seems like all 180W servo has about the same parameters. Had a look at JMC servos as well, and also the Stepperonline, but I don't think I want Stepperonline, due to that crazy RS232 enable solution. I don't know how they were thinking leaving out the EN signal and saving one opto coupler, I want a controllable enable/disable, and I don't regard RS232 is equal to that, since I can't use the same signal I am using for the other steppers, so Stepperonline is out of the picture.

The other thing about the torque is that I want to change the gearing from 6:1 to 3:1 or 2:1 (not decided yet which one) to get higher rpm, so if I do that I will lose torque but gain rpm. Anyway, if those servos are really that good, then I could test with 2:1 reduction, which could give me 1500 rpm on the chuck and about the same torque as I have now with the plain stepper, which should be fine to play with, so right now I am very much tempted to try that out. It's not too late yet to take a step up and use NEMA34, but I would prefer not to, because it would mean a huge change. It would also mean that it starts to become too large for my CNC, which means I might as well give up, which I don't want to do at this stage.

Anyway, it is fun to test this this out, even if in the end, I will not use it for anything serious, but of course, it would be more fun if I could use it for something as well.