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Cura and dual extruder v2

Posted: Sun Sep 30, 2018 4:52 pm
by greg50
I have a taz 5 with a .35 nozzle and also have the dual extruder v2. Lulzbot has shy'ed away from the .35 nozzle. My dual extruder v2 has .5 hex nozzles on it. Changing heads is a pain in the butt with having to load new firmware, reset z-offset (or re-calibrate the z home), and e-steps. It would seem to me that printing with just one nozzle of the dual extruder v2 vs single .5 extruder would be the same thing. I don't really want to buy a new head. So why swap out the head and reset everything.

Why indeed, but cura does not seem to have the materials and profiles for the dual extruder v2. There are only 4 I believe. I assume this is because it only list the combinations that can be used together with both extruders.

Is there a reason I can't use the dual extruder v2 the way I've described. Could I tell cura it's a single extruder and have access to the additional materials and profiles despite the firmware being different. In other words ignore cura when it complains about the firmware being wrong or is there actually a difference in the two print heads that would prevent this.

Greg

Re: Cura and dual extruder v2

Posted: Tue Oct 02, 2018 8:44 am
by b-morgan
The biggest issue you might face with "fooling" Cura and using only one nozzle of the dual V2 is the second nozzle running into things. The dual V2 firmware has the geometry of the two nozzles so you need to use that. You should be able to use the values from the single nozzle profiles but I'm not sure if they can be copied easily.

I believe there are some other topics that discuss this so you might try a search and see if you can find them.

I've done some prints with just one nozzle loaded with filament. The second nozzle goes through the motions but otherwise, the print is successful.

Re: Cura and dual extruder v2

Posted: Tue Oct 16, 2018 7:23 am
by jlund
We have the Flexydually V2 (FDv2) tool head so the following only applies to that type, where the extruders are in front of each other and not side by side.

Solution 1, the first thing I did with our Flexydually V2 tool head was to set it up a second time as a new machine adding "back only" to the name, and then change the startup script by uncommenting the 2nd extruder related lines. It allows single back extruder printing with the profiles for the FDv2 tool head. (Example for Cura LE 3.2.27 attached "Disable extruder 2 startscript"). And additional profile can be setup to run with the front extruder only (in our case the flex extruder).

Solution 2, today I set up a TAZ6 with a single extruder as a machine adding "Dual as single" to the name.
In machine settings changed nozzle size from 0.5 to 0.6mm (optional, 0.6mm nozzle may not be on your dual).
In the startscript I added a "T0" to the beginning of the start script (to ensure all commands relate to the 1st toolhead),
Replaced the wiping sequence in the startscript with the one from the Flexydually V2 machine settings
(Example for Cura LE 3.2.27 attached "Single profile with dual wipe seq startscript").

When choosing this last machine setup, I can now print with all the Taz6 standard profiles for a single extruder, but do it with the Flexydually V2 tool head 1st extruder (back). So all profiles without changing tool head and firmware.

The Flexydually V2 profiles seems to print with a line width of 0.5mm despite the 0.6mm nozzle anyway. The thing I will consider to custom change on some profiles is to reduce print speed to 40mm/s (some of them are 60mm/s), due to the heavier tool head.

Re: Cura and dual extruder v2

Posted: Mon Oct 22, 2018 5:43 am
by jlund
Have been running a bit with solution 2, and it works well.

The exception has been if printing where the first layer is quished so much that material sticks up and affects the unused extruder enough for it to cause the used extruder to now print an uneven layer, which again will cause problems later in the same way etc.

I am not sure how retraction is affected by a nozzle diameter difference between 0.5 and 0.6mm, but I guess it is the same as changing Nozzle on a stock TAZ6?

Re: Cura and dual extruder v2

Posted: Fri Nov 02, 2018 3:30 pm
by mike.stanley
Thanks for this. I was looking for a clean way to just use T0 or just use T1. I knew how to do this in the older versions of cura but couldn’t figure out how to do simple things like shut off temp on T1 since not in use.

Sounds like this solution is the answer. And I I understand you correctly you setup the printer multiple times. Each with different custom gcode to ensure proper head(s) are used. Right?

Re: Cura and dual extruder v2

Posted: Sat Nov 03, 2018 10:39 am
by jlund
Yes, that is correct.

Re: Cura and dual extruder v2

Posted: Wed Nov 21, 2018 4:32 am
by jlund
... for others trying this, note that with dual extruders placed 50mm in front of each other like mine, the front extruder can not physically reach the far back of the build plate area (back 25% or so).

This is the dark area seen in recent Cura LE releases, when importing and setting up a dual print.

If you try to do it anyway (like I have), the printer firmware just move that print or part of it, to another seemingly random place on the build plate.