Hello all Dual Extruder users, both present and future!
I have had many questions about how to use the dual extruder to do specific things (sometimes basic things) that aren’t always straight forward. I thought I would post some of my findings here for the community to work on as well.
The most blatant thing that seems simple but at least in Cura is not straightforward (yet) is how to print a single material part using the front extruder instead of the back. So here goes the simple fix:
Front extruder only on Dual Extruder
In Full Settings in Cura, go to the “Start/End Gcode” tab, and add the following lines to your start Gcode, preferably right after the “G28” command(s):
G1 Y50 ;move Y to new offset position G92 Y0 ;set new Y offset T1 ;activate E1
Now load your STL, place it where you want it on the bed, slice, breathe normally, and print.
You will notice one significant change during the beginning of your print, namely that after homing all axes (G28) the print head will move forward 50mm in Y. This is effectively positioning your front nozzle (E1) to where your back nozzle (E0) usually sits, and redefining that as your new Y=0 position. And yes, for all those who want to be even more accurate, you can substitute your actual Extruder 2 Y offset for the “50”, just to be more exact. And if you are really shooting for pinpoint accuracy you can also add your X offset in there, and then add “X0” to the G92 line.
So if you have a FlexyDually and want to print something big in Ninjaflex, here’s a simple and straightforward way to get it done. Oh, one final thought about this. You may notice that when slicing in Cura with a two-material print, Cura restricts your use of the back of the bed. This is because as far as it knows, your front extruder (E1) can’t travel back there. But if you disable your steppers and pull your bed forward, you will notice that your TAZ can just about make it. Doing the above fix will ignore this because Cura sort of thinks you are still using E0, so it will let you use the full bed, and the Gcode will override firmware limits in the Y-axis (PS, we didn’t lie, we just told Cura to do something without it really understanding what it is doing). Just note that if you call alllll the way to the very back, your bed may come forward enough to hit the frame, and without an endstop there, it will be noisy (shouldn’t hurt much though).
This leads me to one more simple fix, which is…
Using the full bed size with the Dual Extruder
This one is much more simple. Basically, in Cura go into “Machine Settings” and tell Cura that your bed is +50mm long, or 325mm in Y. This will allow you to print over the full Y-length of the bed with your two-material print. That one was easy, wasn’t it! (Okay, this time we lied to Cura. It should get over it once it sees how awesome your print is)
Let me know of other dual extruder functionality that would be good to delve into!