Single Object, Multiple part object printing
This is my first attempt with Prusaslicer 2.3.0 to print an object with two different materials (extruder) with a single mixing hot end. It works really well but while printing there is odd behavior. The hotend will pause for a second or two over the infill area, not extrude any material but just wait. It will do this a few times on each layer and after a sequence of 5 or 6 pauses printing picks up at a normal pace.
I have tower enabled and do not have ooze prevention enabled. Retraction is enabled.
The print looks fine, just odd behavior and consuming a fair amount of dead time.
Any idea what could cause the behavior. I looked at the gcode and nothing was obvious.
RE: Single Object, Multiple part object printing
Do the two filaments print at the same temperature?
Cheerio,
RE: Single Object, Multiple part object printing
@diem
Yes, same type and temp; PLA 204C
RE: Single Object, Multiple part object printing
I looked through the gcode and spotted G4 (Dwell) commands. Never spotted those in other gcodes, had to look that up. The commands were G4 S0 which is dwell for 0 seconds. I wonder if my printer firmware likes that command? Will have to investigate.
RE: Single Object, Multiple part object printing
I edited out the G4 S0 commands and it made no difference. After a tool change and after a trip to the tower, when the nozzle returns to print on the object the nozzle waits for about 10 seconds for about 5 or 6 initial spots on the object then picks up normal print speed. I've looked through the gcode and really can't find any commands to cause or incite such printer behavior. There are alot of M commands I've not seen before; M900 K0, M220 B followed by an M220 S100
RE: Single Object, Multiple part object printing
Unselected tower generation leaving everything else intact and no delays. So it something up with switching from tower to object. I do have the No_Sparse_Layers ON which is an experimental setting. I'll next turn on tower and disable that feature.
RE: Single Object, Multiple part object printing
I don't believe it's a gcode issue. I experiemented with and without the tower. No issues at all without a tower print, but when printing with a tower none of the options under the tower section fixed the 'stall' problem. Looking at the code and watching ack's coming back from the printing software (Repetier) I couldn't pull together the cause. All the experimenting was done via tethered USB printing so I tried printing from the memory card. Printing from the memory card yielded no stalling, so something was / is up with the communications.
In Repetier there is a setting for Communication Timeout. There really wasn't much detail on what this is and does other than it's the amount of time a response (ACK) from the controller card is expected. In my case this was set to 30 seconds. Perhaps that was the cause? I changed it to 2 seconds and now no more stalling. More testing is needed but those are my findings so far.
RE: Single Object, Multiple part object printing
would you be willing to post a zipped up .3MF project file so we could take a look?
The Filament Whisperer
RE: Single Object, Multiple part object printing
@swiss_cheese
Here's the project saved and zipped. Very simple box with two colors. I have a printer with a mixing hot end. Initially iave the "single Extruder Multi Material" box checked, in this example it is unchecked. Unchecking yielded the same exact results for the stalling effect when using USB printing but no stalling when printing directly from a memory card. The unchecking did resolve a very bizarre amount of filament retraction when changing colors though.
My next experiment will be to USB print from a different PC to see if it is PC related. The stalling only happens when printing the tower, if I do the same box in the zip and disable tower no stalling effect occurs.
RE: Single Object, Multiple part object printing
I've been through the profile, the only thing I see that might be causing a problem like you described is extruder 3, it shares the same filament profile as 1 and 2 but in extuder 3's extruder profile the retraction length and speed are set differently in two places. I know that your not using extruder 3 in this example but it is loaded as an available extruder, perhaps it is causing a conflict. Printer Settings/Extruder 3/Retraction when tool is disabled (advanced settings for multi-extruder setups)/ Length: is set to 10mm, the other two are set to 6mm.
Printer Settings/Extruder 3/Retraction/Retraction Speed: is set to 40mm, the other two are set to 35mm.
Also I noticed that you don't have Printer Settings/General/Capabilities/Single Extruder Multi Material: ticked, however it sounds like your using that setup? have you tried this?
I don't have a way to test as I don't share your setup, I have done a great deal of multi-material work, not multi color and I have seen conflicts with material profiles and extruder profiles in 2.3. maybe try getting rid of extruder 3 altogether if its not in use and see how that works, or put extruder 3 to work and see what its affect is.
I was hoping I might be of more help,
Good Luck
Swiss_Cheese
The Filament Whisperer
RE: Single Object, Multiple part object printing
@swiss_cheese
Good catch on extruder 3. I changed the profile so all three extruders have the same parameters and the stalling issue went away.
RE: Single Object, Multiple part object printing
Good to hear 👍 , I feel a bit sheepish as I only just read that you had already tried "Single Extruder Multi Material" I made a B-line for the .3mf file 🤓 and missed that bit.
The Filament Whisperer
RE: Single Object, Multiple part object printing
Still tweaking the slicer as we speak. Appreciate the help.