Hello Guys,

I have a dual extruder (2 Motors, 2 Hotends) here and have been testing around quite some time. So far i am quite happy, but there is one thing that bothers me.

When switching between extruders i have to do a retract on the one that was active and an extract on the extruder that becomes active.
Just for testing i did the following:

T0
G1 E-20
G1 E20

So basically i made a retract and immediately after that i made the corresponding extract. That works fine, no filament leaves the hotend.
Problem: If there is some time between (and there is always some time between the extruder change in real printing) retract and extract, there is always more or less filemant coming out of the hotend and ruins my parts.

Do you guys have any ideas how to solve that?

I think it might help if i lower the temperature of the inactive extruder while the other is printing, but I do not like setting absolute temperatures in gcode-files. Any ideas on that?

Thanks in advance

That is what a purge or prime pillar is for. Check out Kisslicer and Cura for them.

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Hey Sublime,

I dont think that a Prime Pillar helps with my problem. My Problem is that the filament in the inactive extruder probably gets molten if there is a longer phases of no extract-action. At the extract-action there is probably too much hot filament close to the hot-end, so that too much floats out by the time the extruder becomes active again