New to dual extrusion, need some help with slicer setup.
 

New to dual extrusion, need some help with slicer setup.  

  RSS
XOIIO
(@xoiio)
Active Member

Hi all, so I don't have a Prusa printer, but I love PrusaSlicer, and I've just upgraded my printer from the stock random mk8 extruder to a bondtech BMG x2.

One thing is that I'm totally new to dual extruder setups though, and I noticed some weird behavior that I'm still working on, so I may end up fixing myself, but overall guidance would be helpful.

I had set my print to run off the right nozzle as that will be the primary one, and noticed that both of them were heating up at the same time which is undesireable.

I changed my default extruder from 1 to 2, however this time it started heating up the left extruder only which was also the wrong behavior, and I've changed this back but it's still heating up the wrong extruder when preparing to print, even though my model is set to print off of extruder 2.

I'm guessing that for some reason prusaslicer is basically "backwards" from how I have marlin set up, but I'm not sure how I can change that, as no matter what I tweak in settings as I've been typing this, I can't get it to properly use the right extruder.

In  octoprint the extruders are in fact working properly, so it seems like the issue lies in the slicer.

Here are some screenshots of my settings in case something is obviously wrong. https://imgur.com/a/itVFbuf

This topic was modified 9 months ago by XOIIO
Posted : 28/04/2020 10:21 pm
JoanTabb
(@joantabb)
Moderator

Hi xoiio
I am no expert on non Prusa Machines...   does the Ooze prevention option look like what you want? 

 

Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 28/04/2020 10:49 pm
XOIIO
(@xoiio)
Active Member

@joantabb

Hmm, unfortunately not, that puts an ooze shield around my model which will be helpful for when I do dual extrusion, but most of the time I will be doing single and not even have filament loaded in the first nozzle, so right now my struggle is getting the printer to work with a single extruder.

Perhaps my wanting to use the second nozzle as the primary one is unusual, and that's part of the issue but it seems like it should still work, right now it's just trying to use the first extruder even though my model is set to use the second. 

It's just that for how my printer is set up in terms of filament loading and whatnot using the second extruder as my primary one works best.

Posted : 28/04/2020 11:22 pm
JoanTabb
(@joantabb)
Moderator

Why not set the slicer up as a single extruder profile with the offset for the second nozzle as the location for the extruder?

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 28/04/2020 11:38 pm
XOIIO
(@xoiio)
Active Member

@joantabb

I could give that a shot although it seems like kind of a backwards solution to the problem.

Posted : 29/04/2020 12:08 am
XOIIO
(@xoiio)
Active Member

So I've done more testing and it seems like for whatever reason, the gcode sent by prusaslicer isn't able to turn on the second heater. I think it's trying to print using the second extruder, but for some reason will only heat up the first one. 

It looks like this issue is because I'm using starting gcode to tell the extruder not to heat up until after the bed level to prevent oozing, I'm not sure why this is making it use the first extruder and not whichever is assigned though. I'm guessing I just need to use a slightly different formatting for the command.

 

G28 ; home all axes
G29 P1 ; do mesh bed level
M109 S[first_layer_temperature] ; wait for extruder temp

 

Posted : 29/04/2020 6:06 am
towlerg
(@towlerg)
Honorable Member

@xoiio

"In octoprint the extruders are in fact working properly, so it seems like the issue lies in the slicer." Can you expand that a little. Obviously you've set "Number of Extruders" to 2 but how have you confirmed which is which?

As an absolute novice, I would have assumed that the identity of a second extruder was entirely governed by Marlin (only he knows what wires are connected to what GPIO) and controlled by GCode. What extruder related GCodes appear in PrusaSlicers output?

Kludge alert! My other thought was that if this config were permanent (second extruder as primary), you could swap heater etc. wires over. 

This post was modified 9 months ago by towlerg
Posted : 29/04/2020 2:13 pm
XOIIO
(@xoiio)
Active Member

@towlerg

So, I posted in the 3d printing reddit and have done testing, and it's due to having the M109 start command to wait to set the extruder temperature.

Apparently with it unspecified it defaults to the first heater, so to specify the second I need to format the starting gcode like this:

M109 T1 S[first_layer_temperature] ; wait for extruder temp

 

T1 is the second heater, and T0 would be the first.

However, this means editing the start gcode to match each time and I don't know how it handles dual extrusion, I guess it might just heat up other hot end once it's needed and be a bit slower.

There must be some way to have prusaslicer automatically detect which extruder is being used and use some sort of variable for this you'd think though.

Posted : 29/04/2020 7:00 pm
JoanTabb
(@joantabb)
Moderator

@xoiio

the prusa single filament mode in Multi fialment setups, specifies extruder T? which prompts Prusa firmware to ask which extruder to use
If you use prusa multifilament mode, the slicer specifies extruders as T0, T1, T2 etc... so there is no confusion.

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 29/04/2020 9:24 pm
towlerg
(@towlerg)
Honorable Member

@xoiio

FWIW I added a second extruder to my printer profile in PrusaSlicer, selected the second extruder and resliced. The only functional (lots of comment changes) difference was that the GCode T1 was added.

I added a second extruder to my Octoprint printer profile and tried printing  (Virtual printer) both files, they both used Tool0.

I posted the above on the OctoPrint forum.

Posted : 30/04/2020 2:20 pm
intexind
(@intexind)
New Member

Well I think this is all wrong regarding T calls and Extruder Numbers/Positions

I have been working with G code for over 30 years and this is really confusing 

If you call a T call eg. Tool 1 Tool 2 Tool 3 Tool 4 Tool 5 THEN the extruder should be corresponding and not missmatched E1 E2 E3 E4 E5

SIMPLE yeah 

NO Seems like Prusa Has decided to confuse the standard and Use

T0 as E1

T1 as E2

T2 as E3

T3 as E4

T4 as E5

THIS IS VERY CONFUSING ,WHY NOT JUST LOGICALLY MATCH THEM UP AS THEY SHOULD BE ????

PLEASE FIX THIS !!!

Posted : 22/08/2020 2:59 pm
3Delight
(@3delight)
Moderator
Posted by: @intexind

Well I think this is all wrong regarding T calls and Extruder Numbers/Positions

I have been working with G code for over 30 years and this is really confusing 

If you call a T call eg. Tool 1 Tool 2 Tool 3 Tool 4 Tool 5 THEN the extruder should be corresponding and not missmatched E1 E2 E3 E4 E5

SIMPLE yeah 

NO Seems like Prusa Has decided to confuse the standard and Use

T0 as E1

T1 as E2

T2 as E3

T3 as E4

T4 as E5

THIS IS VERY CONFUSING ,WHY NOT JUST LOGICALLY MATCH THEM UP AS THEY SHOULD BE ????

PLEASE FIX THIS !!!

Why don't you report it over on the GitHub Issues for PrusaSlicer (Prusa staff rarely come to these forums)...

https://github.com/prusa3d/PrusaSlicer/issues

Posted : 23/08/2020 1:59 am
Share:

Please Login or Register