Dual extruders single nozzle, any example scripts to start with Cura?

[Mister Fab 0]

Hello all,

 

I am new to Cura, after having using S3D a long time.

 

I am trying to configure my printer (Tevo Tornado, Marlin firmware) to work with dual extruders.

It already works well with a single extruder with Cura, and dual extrusion worked with S3D.

 

Would someone have an example of the configuration scripts used for each extruder? 

I have made several tries but I don't understand how Cura manages the dual extrusion.

 

For example, I have a test cube,  starting full black for  10 layers, then whithe for another 10 layers then back to black etc...

But when the print is launched, it makes a tool change on each layer( retract the PLA on tool 1, and reinsert the same ), just to keep the same color and going back to print.

 

If anyone has any advice, it will be welcome.

 

Thank you for reading

[GregValiant 1,119]

I just reviewed a bug report on Github and it involves the same sort of behavior.  In that case it appears to be a problem with the implementation of the Prime Tower.  There is also a discussion HERE on this forum posted by the same person.  That poster has a 4 in 1 out hot end.

 

If you would load your models and set Cura up to slice and use the "File | Save Project"  command and post the 3mf file here I'll take a look. 

 

Playing with my printer configured with a 2-in-1-out hot end what I found was:

• With the Prime Tower enabled:
  • If the bottom part us printed with T0 and the top with T1 there is only 1 tool change in the gcode file.
  • If the bottom part is printed with T1 and the top with T0 then there are 63 tool changes in the file.
• With the Prime Tower disabled:
  • It doesn't matter which extruder is used for the bottom part - there is only 1 tool change in the gcode.

A bit more evidence that the Prime Tower is the guilty party.  Maybe @nallath has a take on this.

 

EDIT:  I'm getting the same sort of results with a UM S5 as the active printer.

 

Edited November 22, 2022 by GregValiant

[Mister Fab 0]

Thank you very much for your help GregValiant,

 

I'll have a look on the parameters as soon I'll be home tonight, and I'll make you a feedback.👍

[Mister Fab 0]

Hi GregValiant,

 

Only had the time to go back to my printings tonight.

 

I exported you the project.

 

For information, I configured my scripts using a tutorial about dual extrusion and single nozzle

https://www.instructables.com/TEVO-Tornado-Dual-Extrusion-Beaus-TL-Feeder-Versio/

CFFFP_Dual_Extrusion_Calibration_A.3mf

[GregValiant 1,119]

Thanks for the file.

If you haven't done it yet, go to the MarketPlace and load the "Printer Settings" plugin.  After restarting Cura the Printer Settings section will be below the Experimental section.  Within Printer Settings enable "Extruders Share Heater" and "Extruders Share Nozzle".  Those are specific for multi-in-one-out hot ends.  They keep Cura from dropping the hot end temp to Standby temperature when tools are changed.

 

You can use that model for calibration.  Change which extruder prints which model so the model touching the build plate will start out with extruder 1.

When a model starts out with extruder 1 the bug I mentioned doesn't activate.  If a print starts out with extruder 2 is when the tool changes happen every layer change.  On that model it isn't too bad as starting with extruder 2 shows 22 tool changes and starting with extruder 1 shows 18 tool changes.

The top section of the model has that plug that sticks up from the model below so there will be tool changes every layer for the top 10 layers.

 

 

 

 

[MaxS78 0]

Hello, I'm also a new user of 3D printer. Tried several slicers and came to ultimaker cura recently. I found that ulimaker print very carefuly and precisely in respect to my previous attempt. But I'm not enough lucky with configuring 3 extruders with 1 nozzle/heater. Even when i disable 2 other extruders and keep onky one - the all 3 are active during printing. I didnt find any examles of settings for such a case - only "Printer Settings enable "Extruders Share Heater" and "Extruders Share Nozzle"" which did not help to solve my issue. 

The printer: Geeetech 20T

 

I have limited time to print the present for my friend and still have no good configuration... 

[gr5 2,072]

What kind of printer do you have?  There are some non ultimaker experts here.

[GregValiant 1,119]

I just saw this.  Maybe I can be of service.

 

The A20T has a 3-in-1-out hot end and is capable of mixing colors.  Geeetech put mixing instructions in the StartUp Gcode.  I've commented those lines out and made some minor adjustments to the StartUp and Ending gcodes.  You should get one extruder at a time with the changes I made.  I'm not sure that the M163 and M164 commands are actually supported by your firmware so the printer might have been confused by the commands.  At any rate, those are advanced features that you may want to enable down the road when you are more comfortable with the printer.

 

@MaxS78 when (if) you open the attached project file, Cura will ask if you want to "Update Geeetech A20T".  Click on that button and select "Create New".  That will keep this project file from over-writing your current printer.

You will want to check the settings in Dual Extrusion and particularly the "Nozzle Switch Retraction Distance".  You may have customized the numbers and I just used the defaults.  They aren't spelled out in the A20T definition file that AnyCubic provided to UM Cura.

 

You have a couple of days left.  Good luck and Happy Holidays.

 

Geeetech A20T adjusted.3mf

Edited December 18, 2022 by GregValiant

[pozzello 0]

Hiya, having some issues with Cura 5.2.1 and GeeTech A20T (triple extruder) myself.    Main problem I haven't been able to work around is that tool/extruder/color change is leaving a hug blob of the current color on the print before moving over to the tower and priming the next extruder/color.    Tried GV's profile above to no effect...

 

see post and image at

 

Edited January 6 by pozzello

[GregValiant 1,119]

@pozzello I've responded in the other thread.