Re: stepper resolution

Can't be too much help but try dividing the actual distance by the
wanted, it may provide a clue. e.g a simple example would be 0.5 if
half step was selected and you thought it was full.

Are they you a long way out? Are you sure of your TPI's and gear
ratio?

Another simple test. Set it to 800 steps per inch and jog an inch
but take note of the position of the stepper shaft (use a little mark
on it). If it doesn't do a full rev, or does more, that is one thing
ruled out. You can continue doing the same experiment by just
changing the number of pulses per inch to see if the leadcrew does
one rev with the relevant number of pulses to the stepper.

hope that is some help from one newbie to another

Graham