Config Z lead screw 8mm diameter, 1 start, 2mm pitch

General Discussion
2

Just to be on the same page:

  • Pitch - is the distance between screw threads
  • Start - the number of threads that are wrapped around the axis of the lead screw
  • Lead - Is the linear distance traveled for each complete turn of the screw
<lead> = <pitch> * <starts>

This means more Starts equals higher speed but lower resolution

<steps_per_mm> = <full_steps_per_rotation>  * <microsteps> / <lead>

For a regular 1,8° stepper and 16 microsteps:

<steps_per_mm> = 200  * 16 / 2 = 1600

<rotation_distance> = <full_steps_per_rotation> * <microsteps> / <steps_per_mm>

<rotation_distance> = 200 * 16 / 1600 = 2

Or more simple:

<rotation_distance> = <lead>

When you set rotation_distance, then Klipper will no longer depend on your microsteps, this means you can modify microsteps without changing rotation_distance.
For higher accuracy, it is advisable to also:

  • Set microsteps to 128 or even 256 (TMC driver / fast 32 bit board)
  • Change to a 0.9° stepper with 400 full_steps_per_rotation
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