Motors

 
LDO-57STH86-3004A

Stealthchop

We set stealthchop motion because its quieter, and we set it from moves as slow as 5mm/s so that we don't get whiplash from switching between stealthchop (voltage-controlled) to maxspread (pwm-controlled) output at high speeds.

Stall Detection

Stall detection gives us virtual endstops on the maximum X and Y, and protection if a toolhead gets stuck on something.

Note! I am not sure if the rated toque should be 3.0A, or 3.0A * 2 because there are two phases in the motor

A rough figure for the minimum speed in full steps per second (M915 H parameter) for which you should be able to get reliable stall detection is given by this formula:

min_full_steps_per_second_for_reliability = 
  steps_per_full_rotation * rated_current
  * (actual_current/(sqrt(2) * pi * rated_torque_nm)) 

steps = 400
rated = 3
actual = 0.8 Amp
pi ‎ = 3.142
sqrt(2) ‎ = 1.414
torque = 2.4 N/m (from 24.5Kg-cm)

actual / (sqrt(2) * pi * torque) ‎ = 0.075

steps * rated * 0.075 ‎ = 90