1 Topic by Morganism

  • Morganism
  • Member
  • Offline
  • Registered: 2015-01-19
  • Posts: 133

Topic: Dual Extrusion with 3.0mm and 1.75mm

I find myself in possession of 1x 3.0mm J-head and 1x 1.75mm J-head, both with a 0.5mm end on them. Is there reason I cannot use them in a dual extrusion set-up. Are there any problems I might face? Theoretically to me , as long as the filament is coming out the same diameter, and I am able to set the firmware for each separately--it should work.

Solidoodle 4-Mostly stock running off headless Raspberry Pi with Octoprint

2 Reply by wardjr

  • wardjr
  • wardjr
  • Moderator
  • Offline
  • From: Minnesota
  • Registered: 2013-06-10
  • Posts: 5,624

Re: Dual Extrusion with 3.0mm and 1.75mm

I am certainly not the expert with this but I can say that with dual extrusion both steppers need to run at the same calibrated steps/mm.  Since I have little experience with 3mm filament I don't know how close the two would be.  It may be possible to split the difference and make up for that difference in the extrusion multiplier within your slicer.  Either way it seems like a good way to make a complicated process even more difficult.  I would consider just getting another 1.75 hot end.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

3 Reply by jagowilson (edited by jagowilson 2015-03-17 16:43:29)

  • jagowilson
  • PRINTiT
  • Offline
  • Registered: 2014-09-14
  • Posts: 1,701

Re: Dual Extrusion with 3.0mm and 1.75mm

Marlin doesn't let you set steps per mm per extruder axis? I guess that *is* true... Good looking out because I was about to suggest something that will not work tongue

Perhaps with a geared setup running in Bowden you could get the steps per mm for each axis very close, if not identical. Just a thought. If you can drive both extruders with the same hobbed bolt, or at least one with the same OD, I *think* your steps per mm would be the same for each extruder, but I may be thinking incorrectly.

If you can't overcome this hurdle and not get the steps per mm equal, I would suggest not even wasting your time. The results would be... less than ideal.

4 Reply by grob

  • grob
  • grob
  • Member
  • Offline
  • From: Sydney, Australia
  • Registered: 2014-01-02
  • Posts: 900

Re: Dual Extrusion with 3.0mm and 1.75mm

This is true, E steps-per-mm is shared between axes in Marlin. Marlin development version is fixing this at the moment though, so if you're ready to experiment with a pretty wild version of Marlin, you may get what you're looking for. Check out the github page and have a look. smile

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi