Dual Extruder V3 TAZ 6 - poor colour definition

Hi there - We just received our dual extruder for the TAZ 6 - very excited!
Printed the impossible gears with sample PVA - print quality was okay but not great.
Am printing dual extrusion files for OpenRC F1 car - using Polylite PLA green and black - was a 16 hour print at .12 resolution, the green is mixing with the black on one of the dual parts - looks very average. I have included phots and dual extrusion STLs to see if you have any suggestions on what went wrong? PS I also enable prime tower in Cura 2.6.63, thought this should have alleviated any of this colour mixing?

Best regards,
Mike

Dual_Extr_Front_Upper.stl (54.3 KB)
Dual_Extr_Front_Lower.stl (1.4 MB)

Hey Mike,
Thanks for the chat over the phone. As discussed, the most important thing to do before using your Dual Extruder v3 is simply installing the most up to date version of Cura 2.6 from here

Once you’ve installed Cura, strictly following the upgrade instructions, the next port of call is to upgrade your printer’s firmware (remember that the firmware for the tool head is upgraded with each version of Cura too). If you’d like help, or a demonstration of doing that process, go ahead and check out our guide.

After that we can work on improving your Dual Extrusion print quality. The most important setting by far that I’ve seen utilised is the use of both the Prime Shield (enabled by default) and ‘Ooze Shield’ (not a default) within Cura.

image

Essentially, the Ooze shield will be a shield of plastic 1 nozzle width wide that’s positioned a small distance from the model (see below).

With the Advanced settings in Cura, you can change 2 properties of your Ooze Shield. That is how far from the model it will be printed (I’ve found that 1-2mm works well) and the Shield angle (leaving this at the default of 60 works well for most models, however you may need to change it for different geometries).

At the end of your print, remove the model (and Ooze Shield) from the print bed and simply use some side-cutters or something similar to cut away the shield and reveal your print.

Further tuning of the Dual Extruder will be heavily reliant on the following settings (remember if you need help with any of these, mouseover the setting in Cura 2.6 and check out what it means):

  • Printing Temperature
  • Retraction speed and distance
  • Minimum travel before retraction
  • Combing
  • Minimal extrusion before retracting
  • Z-hop when retracting

I hope this all helps, remember to tune each setting, one at a time until you’re satisfied and then move down the list.

Let me know if there’s anything else we can do to help.

Hey Aidan, thanks for your email.
Where do I find the instructions for removing application data - I have uninstalled previous cura 2.6.63 - do I need to remove application data before proceeding with 2.6.69 install?

Mike Smith

Leading Teacher/ICT Coordinator

Wendouree Primary School

1224 Howitt St

Wendouree 3355

(03) 5339 1229

http://www.wendoureeps.vic.edu.au/

Hey Mike,
Just follow the instructions below the download link here.

Thanks Aidan, going through install now with instructions.
Just trying to further troubleshoot - both prints I created G-Code in cura and saved to SD card - this shouldn’t have had a direct impact on performance should it?

Hey Mike,
No it shouldn’t have had much of an impact at all. Let see how the print looks after the changes above :slight_smile:

Hi again Aidan - Wow that print took a long time. Printed with the Ooze shield (that came away easily from the model). Have included one photo whilst printing and 2 post printing. Quality of colour mixing is still extremely poor with black streaked all across the green :frowning:

Hey Mike,
Which Filament/Profiles are you using for this print? I assume the same were used for both prints?

Hi Aidan, yes I based it on high quality profile and then changed the resolution to 0.1
PolyLite PLA (Polymaker) is selected for each extruder - all else is from high detail profile

It looks like your still seeing some oozing between the two extruder tool heads (the unused tool head is slowly oozing into the green during the print).

I’d recommend changing printing temperature of each extruder down to the lowest end of the PolyLite PLAs printable temperature (195 Degrees). As PLA gets hotter, it essentially liquefies. This usually isn’t a problem with a single extruder, but with the Dual extrusion process, you can see that as long as that filament is up around ~205 degrees, it’s causing the black to bleed into the green. So go ahead and change that within the Custom setting in Cura (see below)

mike-1

And then I’d recommend dropping the standby temperature (again visible in the Custom Options in Cura 2.6+). Lower that by ~10 degrees to see if it slows down the Ooze of the unused extruder. You’ll need the Dual Extruder Printer selected in Cura to even see this option, and it will be toward the bottom of the Temperature Settings.

To test out if these fixes work without taking 20+ Hours to print the model files, it might be worth scaling down your existing model, or simply using one of the ‘regular’ dual extrusion model files. The Easter Island heads are a great choice - https://www.thingiverse.com/thing:1560492

Give those changes a go, with your Ooze Shield on @ 1mm distance from the model and see how the results come out.

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