microstepping

can any one help me understand microstepping and what level to choose?

This has a pretty good simple explanation of motors and micro stepping

www.pcbheaven.com/wikipages/How_Stepper_Motors_Work/

Anything above 1/8th is probably getting into the law of diminishing returns, where you are generating lots of pulses and not getting very far.

Depends a lot on the other machine factors, gearing, thread pitch etc and how fast your base thread is.

regards

so I think I understand how the motors them self work so let me explain what happened. I converted a manual mill (jet jmd15) to cnc with nema 23 steppers 570 oz.inch motors with microstepping level 8. Everything was good all axis's were moving fine I left it for a week and when I came back to it all axis would move as if they were only pulsed once and then make a noise that they are missing steps. I tried changing the steps down to 4 and the same thing so I bumped it to 64 and they worked just fine and I was able to use the machine. Any idea on what is happening here?

Do not forget when you change your microstepping at your driver you also need to change your SCALE in Linuxcnc.

linuxcnc.org/docs/html/quickstart/stepper_quickstart.html

Sort of sounds like your hardware setting was changed but not your settings in Linuxcnc.

Rick G

Hi,

By going to 64 from 8 you change the effective acceleration, so it accelerates more smoothly.
Try going back to 8 and lower the acceleration rate you are using. It sounds like you are just stalling from trying to go too fast.
Also, if the machine is cold, you may want to run it through a warm-up program to redistribute lubricant on the ways and screws
Jeff

Jeff
Do you have a crystal ball? because that's exactly what I did immediately before it suddenly stopped working. I wasn't smart enough at the time to put 2 and 2 together. Do you have a warm up program that you like and will share or know were I can find one? Any idea on how low to set the acceleration?

Thanks to all who have responded to help me with this. The links and advice have been very helpful.

Hi,

I don't have any specific warm up program. On my machine, I run the spindle at low speed, and move the axis at a slow rate from home to maximum, then back home (not G28 so you don't do a rapid) and do it again for a few times. Make sure the lubricant is applied before the warm up so it can be spread while the machine is moving. Also make sure you don't have any fixtures or tools in the spindle, but if you do, make sure the program is written so you will not crash any of the axes.

As far as acceleration. Start with a low accel. Then start moving it up little by little. When you finally get to a point where the machine stalls, back off the number by around 15 percent. Same goes for maximum speed.

Jeff