Slaving axis (rotating nut, 2 steppers for Y-axis)

No eBay APP ID and/or Cert ID defined in Kunena configuration4-4.5Nm is pretty strong for a stepper motor. You may have trouble finding a NEMA 23 motor that strong. And even then you are only talking about holding torque (their torque when not moving). The torque drops off quickly with speed.

I've heard good things about the closed loop steppers from Leadshine. Here is a 4Nm one, but it is NEMA 34.


The next refit I do of an old stepper machine, I will probably try to use some of those, but I have not used one yet.

You are right, i found only one 4nm stepper as nema23 (4wires) in the shop where i want to buy the ball screws etc.

...Now you gave me again the idea to use the closed loop steppers from leadshine... I checked the prices at aliexpress: 150€ per kit + delivery costs. (stepper + driver + wires). Wrote an mail to them and asked for the total costs include shipping for 4 kits, but i think it will cost me about 250 € more than i would pay for standard steppers + drivers drivers. Have to think about it, but somewhere i read that its an good combo to use closed loop/servos when using 2 motors per axis. Maybe i should go for it, but lets see how much the total price will be + duty costs.

Just worrying if the setup is more difficult.

I did not suggest using axial bearings, i had them and used them for that test. It is much beter to use deep grove angular bearings as in the link you posted, and that is how it should be done. Mine was just a quick and dirty test to see the diference.
Todd is right, at the speed i was going there was not much torque left and that was with 2NM motors at 80V with extreemly nice stepper drives, with no load at all, just the nut and motor assembly.
Also as Todd suggested, if you do not intend to go over 10m/m, 2505 should do just fine and have more force while cutting at lower speeds.

4-5Nm is in that "grey-zone" where servos start to look better than steppers, but both can do the job.

Thanks tommylight. Good that you said that about the angular bearings, because i think i would order the wrong one..

I think 10m/min. is okay for me, but i am wondering if i reach 10m/min on the gantry axis (will be X i think) when using 2005 ball screw with direct drive.
Cutting at 10m/min is not really necessary for me, so i think there should be no problem when it comes to torque and when cutting at lower speed, i could make deeper cuts. Also like you are saying with the 05 screw i have more force so it will be totally fine ( i think )

@Todd Zuercher: When you are saying "servos", you mean real servos and not the the hybrid servos, right ? Because the hybrid servos are like steppers, but running quieter and have maybe couple more advantages + closed loop.

Guys, does it makes sense to go for closed loop hybrid stepper? I mean, will it make an big difference when using 2 motors for one axis ? I dont know anymore where i read it, but somewhere someone wrote its good to have servos or at least closed loop hybrid steppers when using 2 motors for one axis.

I believe the biggest advantage of the closed loop stepper is not having to worry about stalls or missed steps. But they also run cooler, can have more torque at speed, and like a servo reduce power or apply higher peak power as needed.