new cnc conversion giving me grief

[chrispare]

Ok so I converted my desktop mill to cnc using a hobby cnc kit, This is my second cnc machine, but for some reason I just cant get the steppers to calibrate. I am using mach3, when calibrating I tell it to meve say 1 inch it moves say 10, so it calibrates itself. I try again and move 1 in it moves something else never the same amount. Its all the same direction so no backlash worries. I dont get it.

any thoughts??

 

[RonGinger]

If you are not getting consistent moves you are loosing steps.

Calculate the steps per unit- either inch or mm as you prefer. This is not a 'tuned' number, it must be accurately calculated from the thread pitch and motor steps.

Tune the velocity down until you get a repeatable move distance.

If you will tell us bout your mechanical setup we can determine your steps per unit. We need thread pitch, motor steps per rev ( almost always 200) and if its a micro-stepping controller.

 

[chrispare]

It is a princess auto mill ( Chinese ) that is all I know about it. It's just weird that the last time I did this Mach 3 did all the calculating for me.

Is that any help

 

[rustyknife]

Mach 3 shouldn't precalculate, it hasnt for me in the past at least. The reason it really can't is because every setup is different. Different thread pitch on lead screws etc, and as said previously the amount of steps, and the steps your controller can break each step down into. That number has to be right or nothing will ever work.

Regards,
Eric