Simplify3D User Forum

I've hit this snag now that I'm starting to do my first dual extrusion prints (FlashForge Creator Pro 2016). And it looks like others have encountered the same issue (or very similar) before: here, here, here, here, here and here. But re-raising since it's still an issue; and as far as I can tell, it should be comparatively easy fix compared to other reports / requests.

The precise behavior I see myself, without any custom scripts, is:

• No retraction during startup script.
• First active toolhead performs small retraction before moving to its start location, undoing retraction, and starting print.
• Inactive toolhead does not perform any retraction, and therefore demonstrates considerable oozing until the first toolhead change.

A common suggestion in the topics linked above is to manually add a large retraction of the inactive toolhead to the startup script. This is relatively easy, though must be hard-coded for the known first active toolhead. The issue then is that at the first tool change, the software fails to undo this retraction to prime the extruder, as it is unaware that a tool change retraction has taken place. This therefore requires manual editing of the gcode, to add a tool change extruder prime at the first toolhead change only.

Ideally, the software should should perform a tool change retraction for all but the first active toolhead right at the start of the print, immediately after the startup script. The very first tool change then does not need to be any different to any other tool change: retract the previous toolhead, prime the new toolhead.

Very happy with the software otherwise Keep up the good work!

This is normal case, at Line 20740 is G1 E0.0 F2400, that is "tool change extra restart distance".

But, at first time tool change, between Line 918, 919, no "tool change extra restart distance".
My nozzle looks like this.