Dual extruder frog

[jsc]

Another dual extrusion test print.

Cura with wipe tower, ooze shield, and brim. I think the brim may be mandatory or else the wipe tower/ooze shield get knocked loose at some point.

[Rocketdog]

Nice frog. I also had to use the brim to keep the tower from getting knocked over. The only problem was it was harder to see that I was over extruding. It was evident after I trimmed off the shield.

[markb]

Nice looking frog my boys thought it would be cool made out of Ninjaflex.

[jimc]

nice jin. i always thought that model was cool.

[Tim]

I decided to give the frog a go as my first dual-extruder print (other than the quick calibration test) and with no attempt at using an ooze shield or, for that matter, doing much tweaking of any kind. I just sliced it in S3D and ran with it. Pictures of the results are attached. I think it's not too bad, considering. A lot of oozing, quite a bit of stringing, poor quality on the unsupported severe overhang under the chin. You can see that the black fades out at the top, the result of needing extra extrusion after a retraction.

I also found one bad thing to avoid. The MakerGear wiki said that the factory files for the Dual Julia Vase (I used the right and left processes for this slicing) are without temperature settings. I think this is not true. However, to be certain, I manually set the temperature in S3D. Bad, bad, bad. That causes S3D to issue a tool change in the middle of the communications which gets inserted randomly into the beginning of the print. So at the beginning of layer number 2, the tools got switched. The black filament, which was not retracted, got extruded into a big blob, and then the entire layer got printed in black. So, lesson learned: Don't do anything manually that will send a tool change command. Fortunately, the blob of filament got flattened out on the next pass and the print recovered nicely.

The frog is really a nice torture test for the dual extruder. It's basically a worst-case scenario of a two-color model.

I will now have to go play with Cura and ooze shields. I feel like the ooze problem is not going to be properly solved until somebody comes up with a drive mount that physically moves the nozzles up and caps them off

[jsc]

The S3D dual extrusion support is really not quite ready for prime time. As I reported in the other thread, the tool change sequences it puts in are... unexpected. I had to go in manually and fix them up. It may be suitable if you just post-processed the geode to detect T0 and T1 and insert your own tool change sequences.

I think I went up to 10mm retraction, but it continued to ooze. I haven't gone up to 16mm, which is the Cura default, you may wish to try that. Maybe retract as far as it will go without falling out and see if you still get ooze problems.

The Cura wipe tower serves to prime the incoming extruder, so you don't have to worry about that as much. The ooze tower deals with the outgoing extruder continuing to ooze. Overall, the Cura dual extrusion support is vastly superior, although if you do use an ooze shield your entire model gets encased in a shell which you have to remove. Remember to use a brim either way, as they have a tendency to separate from the bed.

For me, dual color extrusion is a fun little diversion, but the real interesting stuff will be when I get some HIPS for dissolvable supports, or a .50mm nozzle for fast infill.

[Tim]

Hello Jin,

I wasn't expecting great results. I just wanted a baseline of what S3D would do with it before I started messing with Cura.

You mentioned that you selected a wipe tower, ooze shield, and brim. Did you select support? If not, how did the underside of the chin turn out (or is that why you photographed it from the top. . .)? If you need support, does it interfere with any of the other options (wipe tower, ooze shield, brim)? Or does the ooze shield act like a support by itself?

[Levi8than]

I feel like the ooze problem is not going to be properly solved until somebody comes up with a drive mount that physically moves the nozzles up and caps them off

Keep repeating this to anybody that will listen to you.
Once you've moved to a dual extruder setup, how many wires are left on the rambo board to tinker with? Or are we forced to try to retrofit/mux the extruder wires that are already up there?

I'd like to see the extruder mounted on a tilt so that retracting the filament results in the extruder being lifted and capped. Ideally the cap would be self-aligning with a little pin in the center that actually pokes into the extruder. But flat against the opening could work too.

Unfortunately, I could see the cap accumulating plastic and making a mess over time.

[Levi8than]

That's pretty slick.
Add a cap of some sort on the nozzle during retraction, and it'd be perfect. A slide, rather than a cap would probably be less likely to build up sludge.

Kind of like this pancake syrup pitcher's slide:

syrup_slide.jpg (18.61 KiB) Viewed 16954 times

[jsc]

I don't remember turning on support. I think the ooze shield acted as a support of sorts. I'm not at home this week, so I can't take a picture of the chin area.