[CONCEPT] Off-carriage belt driven extruder

Hello fellow tinkerers,

I suddenly got this idea this morning and found it interesting and thought I'd share it to get some feedback on whether I should dwell on it or discard it altogether.

The idea relates to the extrusion mechanism on "regular" Prusa-style printers using geared extruders on the Y-carriage. Usually this causes oscillations in the entire printer upon sudden movements and results in ripples in the printed object, along with other issues. The extruder motor being placed on the Y carriage therefore limits the speed with which one can print quality.

My idea was to remove the extruder motor from the Y carriage and place it on the X idler, opposite of the X motor. This has already been experimented with; Experimental Off-Carriage Extruder Motor. This would decrease the total mass of the y carriage and allow greater printing speeds. But instead of using a rod for the drive gear, a belt is used to drive a pulley, to which the drive gear is attached. See attached image.

Obviously, some logic will have to be implemented for the extrusion, as the extruder must now counter the movement along the X axis.

Do you think this is worthwhile? Please comment.

Edited 1 time(s). Last edit at 06/03/2014 05:45AM by Shafiqson.

I think this is a great idea. The problem as you already know is that the X and the E axes are not independent if you go this way. You will have to customize the firmware if you want to be able to adjust the extrusion rate during a print. If you don't need to adjust the extrusion rate during a print you code run the gcode through a simple preprocessor. Let me know if you get to the testing stage and you would like a preprocessor for some quick testing.

If you really want to go crazy, you can use this idea with a HBot or a CoreXY style bot. You just add a layer of belt on top of what is already there.

---

ConceptFORGE
Wally, GUS Simpson, LISA Simpson, THOR Simpson, Sextupteron, CoreXZ