What causes "missed steps"?

[watsonstudios]

I'm sure there is a thread explaining this somewhere. I was wondering what causes missed steps when using stepper motors? Does it happen within the motor at random or are there conditions that cause it? Is it caused in the communication between the software/controller and the motor? What factors increase or decrease losing of steps? Is it preventable or is it just an acceptable drawback to using steppers?

I'm in the process of building my machine so I want to know how to keep accuracy.

Thanks.

[keebler303]

steppers don't just lose steps.

Lost steps occur for a few reasons:

1 the steppers are too small for the application.
2 you crash the machine
3 the electronics are not properly setup, faulty connections etc.
4 you ask too much of them, ie. high acceleration

When working properly, the motors will only lose steps if they are overloaded.
As long as the motors have enough power for the application and are used properly, you will never experience lost steps.

Matt

[9lrac9]

I went thru all of what you say, for 6 months... I thought it was my prgram , and in the end it was motor tuning, it needs to run at 20% less than your maximim speed. And it also is best to have the largest stepper motor you can afford. Since all of my problems, I have not scraped a part yet...
9lrac9

[watsonstudios]

Thanks for the replies. Yes, I am planning on getting the biggest motors I can afford and I also have a dual motor X axis. It will be a 24x36 table and I would like to get 500oz steppers at least, maybe 2 slightly smaller for the X pair. There are some nice new steppers on Ebay for a good price usually, We'll see.

[gmfoster]

steppers don't just lose steps.

Lost steps occur for a few reasons:

1 the steppers are too small for the application.
2 you crash the machine
3 the electronics are not properly setup, faulty connections etc.
4 you ask too much of them, ie. high acceleration

When working properly, the motors will only lose steps if they are overloaded.
As long as the motors have enough power for the application and are used properly, you will never experience lost steps.

Matt

Very well stated..number 4 is a biggie...
Garry