Stepper Recommendations for Prototype Rifling Machine.

Morning all.

Let me just start by saying I am very new to linux CNC and this strange new world steppers and code.. I am on a steep learning curve and reading as much as I can about cnc and programming can only get me so far. I actually have to start playing with hardware.
So I am after a recommendation for a stepper motor for the prototype machine that can drive at 180 IPM for the X Axis. I am not sure what the torque will be on the motor, but it will be driving (Through a ball screw) a hook cutter that is cutting 0.00015" each cut.

I went out on a whim and purchased some NEMA 34 Steppers, but I am now finding out that they perhaps are not capable of running at 180 IPM? The steppers I purchased;
Manufacturer Part Number: 34HS38-3008S
Motor Type: Bipolar Stepper
Step Angle: 1.8 deg
Holding Torque（Unipolar）: 5Nm(708oz.in)
Holding Torque（Bipolar）: 7.07Nm(1001oz.in)
Rated Current/phase（Unipolar）: 3.0A
Rated Current/phase（Bipolar Serial）: 2.12A
Rated Current/phase（Unipolar Parallel）: 4.24A
Phase Resistance(Unipolar): 1.6ohms
Phase Resistance(Bipolar Serial): 3.2ohms
Phase Resistance(Bipolar Parallel): 0.8ohms
Inductance(Unipolar): 8.0mH ± 20%(1KHz)
Inductance(Bipolar Serial): 32.0mH ± 20%(1KHz)

Drivers:
DM860T
Output Peak Current: 2.4~7.2A (6.0 RMS)
Input Voltage: +18~80VAC or 36~110VDC
Logic Signal Current: 7~16mA (Typical 10mA)
Pulse Input Frequency: 0~200kHz
Pulse Width: 2.5μS
Isolation Resistance: 100MΩ

Ideally if I could get a NEMA 34 stepper to suit the drivers I have that would be great, but not critical. This is a proof of concept build and ultimately I will be using servo's if the prototype pans out.

Kind Regards

A nema is 34 should be able to do 180 inch per minute unless you have an extreme drive reduction.

I believe they will lose some torque at high RPM.

If you look at the motor torque curve, you will get about 200 oz/inch
(1/5 of static holding torque) at 900 RPM and 80 V


(900 RPM = 180 IPM with .2" pitch ball screws)

Evening All,

I played around with some settings and managed to get it about 625 RPM which is about 125 IPM, before the stepper would stall out.

Would the way I have the stepper wired (Bipolar Parallel) be an issue? I chose this because I was reading that high inductance can cause stepper motors to stall at high RPM. Also I forgot to mention that I have a 48VDC power supply, but from the torque chart 900 RPM should be achievable.

For this prototype project, 120 IPM should suffice, but I would be nice to get a better understanding on how to make stepper motors work.

Thanks for your time.

Are you using a parallel port?

Yes I am using a parallel port.

As for load in the stepper. Very minimal. Just the ball screw, which is 900mm long SFU1605 Ball Screw.

I have the HobbyCNC stuff, Nema 34 I think, 200 in/oz, 40v ish power.

Just playing around under optimal conditions I've gotten over 400 in/min on a 5mm pitch ballscrew. But I don't actually machine anything at over about 90 in/min and don't rapid at more than 120 in/min.

Also I remember that the stepper motors act much different with load and no load. ie, hooked up to the ball screw vs free spinning.

Stepper motors, dramatically lose torque at higher speeds. At slower speeds with the ballscrews I have they make in the neighborhood of 100 lbs of force on the table. Near their top speed limit, you can just press on the table to stall it.