how does mach 2 and similar programs know how far to move ?

[Apples]

Hello.

How do the driver programs know how far to move the gantry.

example if my stepper need 200 steps per revolution and i have a acme rod with 10 tpi that meens that i need 200x1otpi equals 2000 steps to move the gantry 1". right?........

now if i use a rack and pinion jow does the program or is it driver card know how far to move gantry or turn motor.


because if using acme thread it needs 2000 steps to move 1" but 2000 steps with a rack and pinion whould surley move the gantry much further.


Whats going on here,

Apples

[ynneb]

Lets say you have picked metric as your unit of measurement in Mach2. You work out how many steps/pulses it takes to move your machine one metric unit ( mm )

Go to configure in Mach 2 and then pick Motor tuning. You will see a step per unit setting in there.
That way any Gcode that is written for metric will drive your machine axis according to the steps per unit setting. Depending how your axises are driven you may have to set the steps per unit setting for each axis differently.

Don't make the mistake of making Gcode for imperial code. Otherwise Mach 2 will think that one unit is mm and in-fact it is one inch.