e_steps_per_mm = (motor_steps_per_rev * driver_microstep) * (big_gear_teeth / small_gear_teeth) / (hob_effective_diameter * pi)
motor_steps_per_rev=64x64 ( 5v 28YBJ-48 Stepper Motor with Gear Reduction)
e_steps_per_mm = (4096*1)/(10.56*3,14159) —–> 96.45 step/mm
4096 step/revolution
1 revolution =16 teeth x 2mm = 32mm
4096 step / 32 mm = 128 step / mm ??