Simplify3D User Forum

Perhaps I'm not using the right search terms, but I haven't come up with other posts about this.

(Running 3.1.1) I've noticed some flaky behavior with using 2 extruders to one hot-end (SeeMeCNC Y adapter). Though I usually get a proper filament purge when changing tools, I spotted this yesterday during a print, and went back & found it in the code. The issue seems to be that while a prime pillar is being built with 2 parts (unique process for each part), a prime doesn't occur when a tool change coincides with changing from one part (or process) to another.

PVA support filament is in T1, but when a T0 is issued, no purging/priming takes place - it just jumps into printing a perimeter with the PLA in T0. Other places in the file purge properly, when the tool change is within the same part.

Desired operation:
Undesired operation:
Am I not understanding something correctly? I've read about not being able to use a prime pillar with processes starting at different Z, but both of these parts start on the bed (secondary part is "low quality" parameters for PLA to fill most of the need for support vertically, then switch to PVA for the final few layers). I've seen the teaser about this very technique being much more automated in the upcoming 4.0, but that won't work for me in this situation anyway due to other reasons.

Any ideas (or links to threads that I missed)? Thanks!

It would probably help if you posted your factory file and then also mentioned the exact layers where the pillar is being skipped. That way others can check your settings.

I am having the same issue in v4.0 as well. My test part is the lulzbot keychain using the stock Ultimaker 3 configuration.

http://devel.lulzbot.com/TAZ/accessorie ... n_text.stl
http://devel.lulzbot.com/TAZ/accessorie ... n_body.stl

The part starts off with both colors in use and the prime pillar is fine. The middle of the part only uses one color, and again the transition from layers with 2 colors to layers with 1 color is fine. The issue is after printing layers with only 1 color, when the 2 color layer happens, the prime pillar is skipped.

I can reproduce this with the default "Ultimaker 3" settings, and have attached the factory file to be sure.

This is the gcode when for the correct tool changes:
This is the gcode that happens at layer 44 when we try to change to tool T1 after printing a couple of layers with just tool T0:
Here is an image of the bug. Notice S3D is printing the perimeter with T1 (green) even though the top of the prime pillar was skipped and is from what was printed on the previous layer with T0 (blue).



I can attach the full gcode if it is helpful.

hmflash wrote:I can reproduce this with the default "Ultimaker 3" settings, and have attached the factory file to be sure.

It looks like you posted the fff file. It would help if you posted the actual factory file (File > Save Factory File)

Oops. Lets try that again.

This issue has now been fixed with Version 4.0.1. The factory file that was provided now slices correctly in this version with the correct prime pillar sequence for the multi-color layers.

Thank you for your help reporting the issue!