Tried to Calibrate Z axis but I don’t understand what is gear ratio and I don’t know how to calculate?
I’m not good with math, I’m still learning it.
I tried to calibrate the Z axis using RepRap website Calculator for MPCNC but
Unfortunately, I miscalculated the gear ratio for the lead screw, I found it confusing.
A 2mm pitch 4 start lead screw will travel 2 * 4 = 8mm with one complete revolution.
Typically stepper motors are 1.8 degrees per full step meaning 200 full steps per revolution. Far less common are 0.9 degree steppers with 400 full steps per revolution.
Microstepping is individual to the driver and to your setup. Typically drivers are set to the maximum number of microsteps the driver allows which is either 16 or 32 for all the firmware versions that V1 maintains. Some drivers have their microstepping set in firmware. Some are set manually using jumpers or dip switches on the control board.
To calculate the steps per mm
steps-per-revolution * microsteps / 8
As an example, if we have a standard 1.8 degree stepper with a driver set at 16X microstepping, we would have:
200 * 16 / 8 = 400
Note that for all the V1 maintained firmware the steps per mm for Z is either 400 or 800. You can also work the problem backwards. Simply guess at the steps per mm (400 or 800), then run a test. Have the Z axis descend 10mm using either the display or your g-code sender. Measure the result, and adjust the value as necessary.