View Full Version : Advive needed.

01-06-2010, 07:56 PM
Hi all, just would like to know the following if anybody would be so kind to help as it would be truly appreciated. I am now at a stage where I am tuning the motors in Mach 3 but things are seeming extremely difficult to proceed as I am doing it step by step and its just taking forever and I have searched high and low and would like to know the answer to a query. I have a bi-polar 3 axis drive combo type and it was from the Alien CNC guy which I bought about 4 years ago and on it it says 1/8 microstepper, now I have 8mm threaded rod as my leadscrews on all 3 axis and need to input in the Mach 3 section where it says motor tuning and set-up the Steps per inch and do not know what or how to work this out, what would this be ? also what do I input in the box where it says Step Pulse and Dir Pulse ? my motors are Nema 17 type ones if it helps. I would appreciate any help possible guys as I'm nearly there but not quite....... Kammo1.

01-06-2010, 08:51 PM
8mm threaded rod is 1.25mm pitch so one rev of the motor = 1.25mm movement. The motor has 200steps/rev so 1 full step = 1.25/200 = .00625mm and if it 1/8 microstepping 1 microstep = .00625/8 = .00078125mm which is 1280 steps/mm or 32512 steps/in. Step pulse and direction pulse are the pulse widths needed for the driver to recognise the pulse. 5 is a good value to start with.

All this is explained in section 5.5 of the MACH3 manual (http://www.machsupport.com/docs/Mach3Mill_Install_Config.pdf)

02-06-2010, 02:24 PM
Hi many thanks for the advice and how to work this out. Now I know it may sound odd but what do I enter in the Steps part 1280mm or 32512 inch measurement ? my guess would be 1280mm as I pressume when I selected the Native Units in the Config menu I selected mm am I correct or not ? also do I set the Step Pulse and the Dir Pulse at 5 ? sorry for the dumb questions.......

02-06-2010, 05:17 PM
if you have set native units as mm then it wants the number of steps per mm, i.e. 1280. A pulse of 5 in both boxes should suffice

02-06-2010, 11:29 PM
Many thanks Irving for your advice. I had a visit from John S today and within literally 10mins had the machine set up and configured correctly and again many many thanks to yourself and John for sound knowledgable advice,now I am safe in knowing that the machine will cut a given dimension and know its correct. All I have to do now is work out and learn going from CUT 2D to Mach and start producing some stuff, can't wait!!!!!!!