Hello to all,

I have a question regarding calibration of 3 axis CNC Router using Mach3 automatic axis calibration. My machines working area is (X)1830mm, (Y)5000 & (Z)400mm. I've been calibrating the steps per unit using the automatic axis calibration module in Mach3 using measuring tape along the full length of the machine in all 3 axis e.g. I would ask the machine to go 4500mm in the Y axis, 1500mm in X axis and 350mm in the Z axis, then measure the distance traveled using a measuring tape and punching in the number that it has traveled and let Mach3 take care of the mathematics. Now this method is yielding somewhat satisfactory results in terms of accuracy.

In search of finding a better way to measure the distance traveled I started searching online and I've seen many people using a dial indicator having a throw of only 1" to measure the distance traveled. I want to know if moving the machine while calibration say 5000mm in Y axis as compare to 25.4mm in the Y Axis would yield the same result or not. If calibration of a larger machine like I have can be calibrated using only 1" movement in all 3 axis yields the same result as compare to moving the machine 5000mm then I would want to invest in a decent dial indicator with magnetic base and swivel arm from mitotoyo or starret to calibrate my machine as accurately as possible.

one of such videos that I've seen on youtube is:



Any or all info/help will be more than appreciated.

Best regards,
MAQ