2

Question background:

I am building an extruder / hotend combination to be used with 2.85 mm filaments.

The extruder I chose is QR Extruder from Bondtech which comes with a stepper motor, with an integrated planetary gear system and a reduction of 5.18 to 1.

The motor's specification states that it has a backlash of less than 1 degree.

I have contacted the manufacturer but I could not get a more specific number.

Here is what I'd like to know (i.e., my question clarified) :

  • How does this < 1 degree backlash translate to pushing filament through the hot end?
  • Once the extruder steps are calibrated, can it cause artifacts on the prints?
  • Can linear advance (Marlin) or pressure advance (Klipper/Duet) make up for this < 1 degree backlash of the planetary gear system?
Trish
  • 22,760
  • 13
  • 53
  • 106
Phil
  • 153
  • 4

1 Answers1

1

During normal extrusion backlash has no effect.

During retraction you can perfectly compensate by increasing retraction length slightly.

Backlash cannot be taken into account for pressure advance, but unless it's a lot, it should not cause issues: pressure compensation is a second order effect and does not need to be tuned super accurately to produce results.

One degree does not seem to be enough to cause problems.

FarO
  • 4,610
  • 21
  • 39