Problems on dual extruder prints

[MadBoat]

Hey guys,

So my Flashforge Dreamer works well when doing single extruder prints (with either extruder in isolation). I do notice that the filament doesn't start flowing properly until the printer has been going for a few seconds, but this is adequately addressed by adding a skirt to all my prints (and this is a standard option in the version of FlashPrint that I'm running). I would like to know what is the likely cause for this hiccup (temperature differences within the extruder? Stepper motor failure in the first few seconds?), but it doesn't pose a problem with single extruder prints.

When dealing with dual extruder prints, I'm having a flow problem with the left extruder. The left extruder is the "secondary" extruder in these prints, and its only task is to fill in 1mm thick lettering on the surface (it's flush with the material from the other extruder), so it gets very little continuous activity compared to the primary extruder. I expect that whatever is causing the initial delay on extrusion in the single extruder case is the same reason its not extruding initially in the dual extruder case. My solution was to try to add my own "skirt" for the secondary extruder in my CAD software to do before it did my lettering... unfortunately, FlashPrint got the order wrong and it prints the letters before it prints the skirt, so it's no help.

If anyone recognizes the core problem as having a mechanical solution, I'd like to hear it, but failing that... I know it's possible to mess around with G code to change the order of things (and, apparently, to add pauses and other stuff), but cracking open a .g file in a text editor showed it to be a daunting task. Is there a 'right' way to do manual changes on g code that is bound for a Flashforge Dreamer?

Jason

[MadBoat]

So I found a workaround that works, more or less... using the skeinforge slicer instead of the default slicer (slic3r) seems to produce better results when I add a manual skirt (although it might also just give better results period... didn't test that). Would still like to know what's going on though.

Jason