dual extruder prints

[Polygonhell]

I've been messing around with dual extruders for 3 or 4 weekends now, and finally have what I consider to be decent results.
The above were printed in clear and green PLA @ 190C , I'm using a Kraken with two of the hotends mounted, the set screw for height adjustment really is a godsend.

The short version of things I've learned.

• Use the hotend offset in the Slicer, not the Firmware - The latter just ends up adding a delay to hotend changes and given the unused hotend more of a chance to ooze onto the print
• Most of the Slicers do really stupid things that make it harder than it needs to be
• Use Cura - AFAICS it's the only slicer with decent multi printhead support, the ooze guard is a big win (see my blog for pictures)
• There is a sort of no mans land of retraction between head swaps which will almost guarantee a jam - 2mm is fine , 5-10mm jam, 16mm is fine

FWIW I also purchased Simplify3D during this period and it has what can only be described a laughable support for multi extruder printing, basically it technically supports it, but there is no built in support for even a wipe/prime tower never mind something like Cura's ooze guard.
I did not test the new KissSlicer Beta, or Slic3r, the latter because I gave up on it a long time ago.

[Generic Default]

So which came first, the dragon-lizard or the egg?


Really nice prints though. You should try printing the egg as a glow in the dark blue and the dragon-lizard as an opaque olive or green. Have you tried printing with combinations of polycarbonate, nylon, PVA, and flexible filaments? There are a lot of things that might stick to each other for use as support material and you're one of the few people doing this.

I agree about the support for multiple extruders. When I got my rostock last year, I had the impression that dual extrusion was easy to do. Derp. It's still kind of undeveloped both on the hardware and on the software side. Lets hope it gets better.

[Polygonhell]

I'm a a bit short on PLA right now, so it got printed in what I had on hand, I usually prefer to print test things in opaque colors, it's easier to see the issues.

Translucent filament is so forgiving, the green dragon for example has 3 or 4 layers where repetier didn't actually correctly swap extruders, it's not a GCode issue and I am unsure if the issue is in the firmware (at least one similar issue was "fixed") or if it's a comms issue, I was seeing comms errors during the print. The transparent one doesn't have the issue, but for that one I used the Slicer extruder offset, and reduced the baudrate I was connecting at.

I've ordered some T Glass to test as support with PLA and ABS, it might work because I know of people who claim PETG can be used as a support material for PLA, and both PLA and ABS will adhere to PET tape, T Glass is a PET based filament so we'll see. I'll also pickup some HIPS which people have been using with ABS.

Nylon unfortunately pretty much doesn't stick to anything.

It looks like Ultimaker are going to ship a dual extruder version of their printers, so there is a good chance the support in Cura will continue to improve, it's really much better for multiple extruders than any of the other slicers I tried, and the only one with any attempt to resolve the ooze issue.

[Generic Default]

Yeah I almost always use Cura. For whatever reason, slicer always caused my Steve's extruder to vibrate during retractions regardless of what speed I set for them. Identical retraction gcode made by Cura didn't do that, so I'm still confused as to why it acts the way it does...

Translucent filament really does help cover up imperfections. Glossy opaque stuff like trimmer line nylon highlights any tiny surface finish imperfections. Matte stuff like ABS doesn't show mistakes as much.

I want to try every filament on the market. And I want to introduce some to the market! Hot glue sticks can be converted to filament, which I want to experiment with soon. I also want to extrude glass filled stuff such as Polyphlalamide into filament, since it can be made as strong as mild steel and with rigidity five times as much as the plastics we're using now.

PET may turn out to be an excellent support material.

[bubbasnow]

FWIW I also purchased Simplify3D during this period and it has what can only be described a laughable support for multi extruder printing, basically it technically supports it, but there is no built in support for even a wipe/prime tower never mind something like Cura's ooze guard.

i have duals running really well on the s3d, basically i turned off all of the ooze check blocks on the advance page and inserted into the tool change gcode:

G1 E-10 F1500;
G92 E-10.5;

this would just suck out an extra 10 of the filament and prime it with .5 when the tool is selected again.

[img]https://lh4.googleusercontent.com/-AC_K ... 191314.jpg[/img]

[Polygonhell]

I did something similar to get prints out of KissSlicer, the issue I have is that even with 30mm retract at extruder change, there is still plastic left in the nozzle and it oozes out ending up wiped on the outside of the model.

[bubbasnow]

yea it definitely requires a lot of tweaking to get that square... and truth be told once i got it set up i haven't printed with dual extruders (moved on to other challenges)

i might wait till the D3D autolift gets developed more before and use my e3d's for quick tool/nozzle changes