Simplify3D User Forum

I'm using Simplify3D 3.0.0 and a MakerGear M2 with a dual extruder head. T0 is the left extruder and the one I consider the "primary" extruder. T1 is the right extruder. T1 is offset from T0 on the X axis by +31.1mm.

I have set up my printer with PLA on the left side and PVA on the right. I notice that you have a process setting that comes with Simplify3D 3.0.0 that is for "PLA (right), PVA (left)". I took this process setting and modified it trivially so that PLA was on the left and PVA on the right. It shouldn't much matter because they have very similar properties; it's just a matter of which one prints the object that is meant to be the printed part, and which one prints the object that is meant to be the support.

I found one fairly major issue with the dual extruder printing. Because there was a lot of confusion figuring out just what it was that was going wrong, I have edited my initial response, removed several follow-up posts, and condensed it to just the single issue that it boiled down to.

On startup, after purging, the left extruder goes to the starting print position and begins without the inactive extruder being retracted. The gcode shows that the gcode inserted for tool changes does not do a retraction on either tool until the 2nd time that tool is made active. Unfortunately, that means that the inactive tool, having just been purged but not retracted, will ooze all over the first layer of the print. The solution would be to always first activate the tool that is not the first to print, retract it, then activate the tool that starts the printing; and then do the retract/restart for every tool change after that.

(edited; the stated problem has been moved up to the first post)

I was able to work around the problem by using a manual script for the tool change. Unlike the automatically inserted gcode, which does not do the retraction on the first activation of each tool, the gcode script runs every time. So if the start script leaves the second extruder active, then everything should work out right.

Except it doesn't. It reveals another error, which is that the software does not detect that the second extruder is active at the end of the start script, and then (weirdly) does a T0-to-T0 tool change. . . Ideally, (1) it should figure out from the start script which tool is active, and (2) it should never insert the tool change script where a tool is not being changed.

In this case, it is possible to work around these errors by doing an additional retraction of the second extruder at the end of the starting script. The T0-to-T0 tool change then retracts and restarts the first extruder, unnecessarily, but the action is harmless; and the second extruder is properly retracted when the first extruder starts printing. This is a rather complicated way to work around the bugs, though.

Why don't you just add a retraction for the idle extruder in your starting script after you purge it? That seems like it would solve everything without the need for a custom tool change script.

As a fellow beta owner of the dual extrusion upgrade for the MakerGear M2 I agree that everyone will consider the left extruder the primary on a MakerGear M2 and Simplify3D becomes a mess because it assumes the opposite. This should really get fixed as it's going to come up a lot more once the dual extrusion upgrade becomes more widely available.