Hi guys,
I'd like to start a topic in which we can all verify our calculated E_steps_per_mm values. For the new people (me up until yesterday): this is the number of steps your extruder stepper motor must get to pull/push 1mm of filament through the extruder. The formula to calculate it depends on the mechanical construction of your extruder of course. Let's all explain it for our own extruder and verify?
I have a regular Adrian's geared extruder, with following specs:
Nema17 motor with 1,8° per step
Gen6 electronics = 1/8 microstepping is used > it thus needs 8 microsteps for a revolution of a full 1,8° step
pinch wheel diameter 7mm (Mendel-parts Brass insert)
59/11 gear ratio. (ratio of the driven gear vs. the drive gear of your extruder stepper motor)
E_steps_per_mm = 360/1,8° * 8 * 59/11 * 1/(Pi*7) = 390,2397 theoretical steps per mm
correct? thank you!