I have a SFU1605 ball screw and a nemma 34 motor. The ball screw has a pitch of .1957 TPI. My stepper makes a full revolution with 200 steps. It is rigidly coupled to the ball screw directly. There are no pulleys or gear reductions.

Under the Control Configurations tab, under motors I have set the Counts per Unit to 1022.

That is, 200/.1957 = 1022. This does not work. When I set the jog to incremental say .1. The distance traveled is much much less. Can anybody shed any light on why this is not working? I am working in inches.

This is my first CNC retrofit and I am new to this software so it is possible I am missing something very fundamental. Feel free to ask any and all questions.

Also, just some other information that might be helpful. I am using the Pokey57 controller with pendant. My motor driver is a Wantai DQ860MA.

https://www.poscope.com/product/pokeys57cnc/

https://www.wantmotor.com/hybrid-stepper-motor-driver/2-phases-hybrid-stepper-motor-driver/dq860ma-hybrid-stepper-motor-driver.html

I'm also running the Mach4 Hobby License.

Check the setting of your Wantai dip switches (SW5 to SW8) that is the actual steps per revolution you should be using in your calculation.

Tweakie.

You have to factor in the fact that your drive might be micro stepping. My  Gecko's have a 10 micro step so mine is. . .

Screw is 5 turns per inch
motor is 200 steps per rev
drive is 10 micro step

5 x 200 x 10

10,000 steps per inch

My drives are fixed at 10 micro step but some can be changed with dip switches. Check the paperwork that came with your drive and check out your dip switch settings.

Using my value on my motor controller seemed to work. My question is now, what is the best value to use. I used 21600, but there is a 51,000. It seems like the stepper is very noisy when moving fast. Is the rule of thumb with the pulse value the more the better? What is optimal for a 1600 oz-in nemma 34 running at 3.5 amps?

Hi,
the main reason we use micro-stepping is smoothness of motion, the more micro-steps the smoother the motion.

Its tempting to believe that you are increasing the resolution, but it does not work out that way in practice, its to do with
rapidly degrading differential torque between micro-steps. In reality at 1/2 stepping, that is 400 pulses per rev, is the best practical resolution
you can achieve with a two phase stepper.

Increasing the micro-stepping requires an ever increasing pulse rate from your controller, so there is a balance to be struck.

The best balance appears to be about 8 micro-steps per full step, ie 1600 pulses per revolution. Some drivers have a choice of 5 micro-steps, 8 micro-steps,
10 micro-steps or 16 micro-steps. Any of these choices would be fine. Note that would result in 1000 pulse/rev, 1600 pulse/rev, 2000 pulse/rev and 3200 pulse/rev
respectively. One of those numbers may result in a pleasing round number in Machs 'Steps per Unit' setting, and certainly not essential, it is convenient to have
such a number. My machine, in mm units, has a Steps per Unit setting of 1000, that is 1um per step....easy.

Once you set the micro-stepping regime you want in place then leave it alone. It introduces way to much confusion to change the micro-stepping often.

Craig