Cura 3.2.23 with flexydually v2

Running with S3D as I have had no luck at work with Cura 3.2.21 in getting a decent print on our TAZ 6 w. flexydually V2 print head. An example was that the two different extruder parts would randomly shift distance to each other on the build plate almost every time - it is like no one had actually used it before release.

Trying out 3.2.23 it is still not possible to get a decent print e.g. with Colorfab XT (Using Chromastrand inova-1800 profile) and Ninjaflex.

There seems to be massive over extrusion with recommended settings, and trying custom settings it is not clear what happens.

Changing custom settings and generating a g-code file (flowrate 95%, skirt lines 4, enable wipe tower, disable ooze shield), and then change to recommended settings for both filaments and generate a g-code file, the two files are identical in content. It looks like changing between custom and recommended settings does not start a new round of slicing. Is it really supposed be like that?

I guess the combinations of printers and tool heads are too many to test with a SW before release - are new Lulzbot Editions only testet with all the printer- toolhead combinations by users?

Another example is if I delete all settings with rm -rf ~/Library/Application\ Support/cura-lulzbot on mac, set up the flexydually V2 tool head and choose Inova1800 material, the profile choices are:

High detail 0.15mm
High speed 0.32mm
Standard 0.45mm

I doubt “high speed” is quicker than “Standard” due to the lower layer height?

With nGen:

High detail 0.18mm
High speed 0.4mm
Standard 0.425mm

In generel layer heights for all the materials seems quite random between each other, considering they are supposed to be printed together.

I am thinking that nobody looked at this prier to release, and it makes me wonder if all the other parameters for all the materals in there have the same level of quality and why … does “Lulzbot Edition” only include installing printer support in Cura and not material profiles anymore?

Sorry to hear that you are experiencing these issues in Cura. I’m not sure what kind of shift you are seeing with the tool head, but if you have any photos of the shift, seeing those would be extremely helpful to nail down the cause of the issue there. For the over-extrusion, it could be either an issue with a setting in Cura that is the cause, or an issue with the esteps being set too high. If we could see some photos of the print along with the settings you are using for it, we could also help out there.

When swapping from Recommended to Custom or vice versa, Cura will save the changes that you make to each so that you can make changes easier if you are going to be swapping between the two frequently. You can always tell if there is a change in the profile by looking at the profile setting, as if there is a change from the recommended setting, there is a small star that appears. If there is no star, all the settings are set to standard. A quick way to reset the settings is to swap to a different material or profile, as Cura will then ask if you want to keep any custom changes. If you select discard, then it will reset everything to the standard for the new profile, and if not, then it will apply those changes to the new profile.

With the profile quality settings you are seeing in Cura, higher layer height does not always mean a faster print. With each of those settings, the print speed for the high speed ones are greatly increased compared to the standard speeds. The layer heights that they have are ones that we have tested and found compensate really well for the increased speed, so that you aren’t sacrificing too much quality for speed.

I hope that this helps!

Thank you for a helpful reply.

I don’t have pictures of failed prints, but the extruder 2 part would shift compared to the extruder 1 part for the entire print with an offset. 4mm for one print, then a few centimeters for one print, then completely separate 6ish centimeters. Always along the y-axis. Despite being correctly placed in Cura before printing. Did not happen with the latest version of the Old Cura LE (2.21?), not with 3.2.23, not with Simplify3D.

“When swapping from Recommended to Custom or vice versa”
I did that. It is when there is a little star and I choose recommended, there is no re-slicing - see attached pictures - the print time is the same. I would expect default settings to be sliced with, when choosing “recommended”?

“With the profile quality settings you are seeing in Cura …”
I see - the old concept of layer height defining speed is abandoned. Still, too confusing that materials supposed to be printed in pairs almost all have different layer heights for different profile names. In that respect “standard” is anything but. And is it “standard” for Extruder 1 or 2 that wins? and will that lead to a good result?

Example: If I choose Inova1800 high speed and Ninjaflex high detail and enable prime tower custom setting - as a user I am hard pressed to guess what will happen. Do Inova1800 print with high speeds best suited to 0.3mm but now with a layer height of 0.15mm?

Again, if I then choose recommended, so it will appear to be the choice for both extruders, there appears to be no re-slicing, so custom will still run when I save the g-code…

… looks like only “Custom” print setting picture got in there - here is the “Recommended” print setting picture attached.
(Notice that despite having chosen “Recommended”, the slicing time is still the same, so “Custom” is actually still used when saving g-code).

Another example that makes me wonder are line widths for INOVA1800 and other materials. They are all 0.5mm for TAZ6 with FlexyduallyV2 tool head having 0.6mm nozzles as I understand it. Seems a bit low and not related to real physics. S3D auto setting is 1.2 x nozzle width.

Is that really a good idea for some reason, or is just that they were not changed from a config file from a stock TAZ6 with 0.5mm nozzle, where line width’s are also 0.5mm for the materials I checked?

When making changes in the custom settings, Cura is essentially saving them as changes to the recommended profile, as you are making changes to the standard profile. So when you go back and forth between the recommended and custom, all those changes will remain, so there is no need for Cura to reslice the print.

With the layer height, Cura will do its best to try and find the middle ground for both filaments, as both extruders will need to print out at the same layer height. So if you have a High Detail set on one extruder that prints at a .18 layer height, and a High Speed set on the other that prints at a .38 layer height, then Cura will adjust the settings in both profiles to print at a .28 layer height.

The nozzle diameters are already accounted for in the Machine Settings under the Hot End tabs. They are both should be set at .6mm for both nozzles, so if you are seeing any difference there, then you will want to change them back to the .6mm for the best results.

Hope that this clears things up for you!

That combination explains a lot, thanks. I need to RTM but can’t find one for dual material extrusion with the latest Cura LE?

Yes 0.6mm Nozzle is default in machine settings on a fresh install after cleaning preferences and all. The issue is a line width of 0.5mm for all filaments despite that 0.6mm diameter nozzle - is that an intentional default in a fresh install or a bug?

Also, I just noticed that a major advertised reason for us to buy a double extruder - printing with PVA - is gone as a filament option after being present in the old Cura, is that intentional or a bug?

The .5mm settings are intentional in Cura, even though the nozzles on the Flexydually are both .6mm. The exclusion of PVA for the v2 Dual and the Flexydually was intentional, however we are working on bringing it back for the Dual v2, but it is just needing a bit more testing. If you are using Cura 3.2.27, the PVA profile is in the experimental filament category for the v2 Dual, so you may be able to have an easier time adjusting it to the Flexydually if you are wanting to use it for your prints.

Thanks. We were hoping we could just start printing, but hope to see PVA soon then.

That makes no sense to me - I have never heard of that going well. In other slicers you would get a warning. I am thinking it is a Cura thing, but then i don’t understand why other toolhead profiles are not doing the same ?!?

In Cura, you will get a warning if you make the settings higher than the nozzle’s diameter, but Cura is able to adjust the feed rates to allow for .5mm flow through the .6mm nozzle, so no error is present there.

As for the PVA profile, you may be able to transfer those profile settings over and use them for the E0 extruder, as you would not need to make many changes to the feed rate for that. Just keep in mind that it is an experimental profile, so there may be a fair bit of testing and adjusting to get it to print perfectly.

In principle I guess - as long as the 1.2 ratio between layer hight and width is observed.

In real life it was less convincing on a known setup - my Mini at home printing 0.2mm layer hight, 0.4 layer width, 0.5mm nozzle. Extrusions on a flat surface seemed ok but things like curved overhangs are less succesful.

Anyway, in the meantime I found this post:

Is that what to expect from TAZ 6 with colorfabb XT or is that just considered “working software”?

… Sorry if that was an impolite question, I am trying to understand if that print is the best I can expect. It is better than what I can achieve so far.

Trying to print colorfabb XT/Inova1800 (XT) and Ninjaflex with FDv2, I found out that XT flows really well with 270C and fan 90-100%, but max 20mm/s or curved overhangs “fall over the cliff”.

Unfortunately with a dual print, the printer stops during tool change, with a “Heating failed E0 PRINTER HALTED Please reset”.

It seems during tool change where nothing is moving waiting for heating the extruder for the next layer, the tool head can’t heat up E0 to 270C (from 160C resting) fast enough with the fan set to 90%, without kicking off the safety routine.

So I first turned off the fan in the tool change script (S3D), but could not find a way to start the fan afterwards (tried M160 R2 but that kicked the fan to 100%):

G1 X0 F4000 ; move to wait for temperatures
; M107
{IF NEWTOOL=0}M109 S[extruder0_temperature] T0; Set T0 new active extruder to T0 Temperature and wait
{IF NEWTOOL=1}M109 S[extruder1_temperature] T1; set T1 Heat T1 to T1 Temperature
; M160 R2

So I removed the fan off commands, and with the fan at 90% or 100% the hot-end can’t reach 270C while printing anyway, so I lowered the print temperature to 260.

But this lead to a clogged nozzle (like a heat creep) during normal infill at 6-8th layer at 30mm/s print speed (20mm/s outlines).

Upping print temperature to 265, the same thing happens but a couple of layers later, and I see the hot-end does not reach 265 until quite a few minutes into the session.

So now all I can think of is to lower the fan speed and print speed to help out the tool head?
Or is it just not realistic to run the tool head at these high temps - any experience?
In a tool change script, can I restart the fan at the previous speed without hardcoding it?

Finally found experience with Colorfabb XT / Chromastrands Inova1800 that perfectly sums up my own experience with it incl. print settings. Would have saved me and the company weeks of wasted time so listing it here).

To sum up the most important point regarding using these for engineering purposes: The filament can’t have smooth surface finish and handle overhangs well at the same time.

With 3DBenchy as an example, I could print a poor surface Benchy at 225C with structurally ok front and nearly ok chimney, or a perfect surface Benchy with eg. crashing back-end and front and bad chimney at 260C.

Also overhang handling was clearly worse with the Flexydually V2 0.6mm nozzle compared to my Lulzbot Mini 0.5mm Nozzle. Despite the better cooling fan, printing 0.5mm width with a 0.6mm Nozzle does not level the score at all with this filament.

Back to square one and find another plastic …

… I should add that I suspect that both perfect surface finish and overhang handling maybe could be achieved printing with a printer with:

  • an all metal hot-end extruder for 1.75 mm filament
  • able to deliver more heat
  • with a stronger multi-sided part cooling fan that only cools the print
  • with a smaller nozzle, maybe 0.4mm is small enough with the above

I would love to see a super nice 3DBenchy with this filament - it ticks off all the boxes except for not being printable with the printer we have (Taz 6 with Flexydually V2 toolhead).