Clogs and Colorants

[Luuk]

Last time we had our first encounter with the green recycling machine. It was exciting to say the least. After receiving some vital tips from the masters themselves on how to tune the Filabot, we further explored the possibilities.

We began with feeding the machine some rough shavings of failed 3D prints. That was a huge mistake. It did produce some ‘filament’, but the quality was far from printable. This wouldn’t have been a big deal if it wasn’t for all the hours we had to put in to clean out the Filabot. Lesson learned. We will now wait with recycling failed prints until we receive the Filabot Reclaimer. This nifty device helps you grind your failed prints into consumable shavings.

Another experiment we we’re excited about was to mix the raw ABS pellets with socalled colorants. So whilst getting rid of the last residue from our recycling experiment, we began running some tests. We read about a mixture of 1/10, so that’s what we went for. The result was quite astonishing. At first it was a combination of stringy PLA blubber and ABS, but soon the red color showed up. At first the diameter of the extruded filament was way off, but eventually we managed to find the right temperature for ‘spot-on’ 3mm filament extrusion (or so we thought).

Next stop was the printer. Since we extruded ABS we didn’t build up our hopes too high for getting a good result on the Ultimaker Original. Printing regular ABS filament is a challenge already, let alone your own recycled ABS filament. As you can see on the picture, the ‘Cute Octopus Saying Hi’ doesn’t raise just one tentacle… heavy warping occurred while printing.

We came to the conclusion that a heated bed was a necessity, so there was no other option than to run the filament through our beloved and well taken care of Ultimaker 2. We were a bit hesitant, because maintenance on the Ultimaker 2 is harder than on a Ultimaker Original. Our nightmare became reality. The nozzle clogged mid-print, although the temperature was set on 240 Cº. We think it had to do with the variation in diameter. What followed were countless hours of poking needles and thin metal threads in the nozzle, and even molesting it with a creme brulée torch. It’s no fun having to hurt your baby like that.

For now we leave it at this; diameter consistency is very important in being able to print with your own filament. We tried variations in temperature of the Filabot, the angle of the Filabot and also the height of the Filabot from the floor. None of these attempts resulted in evenly wide 3mm strings. We’ll definitely run more tests, but in the mean time we’d love to get some tips from you guys on how to reach the perfect constant diameter and how to spool the freshly extruded material.

[hachu]

I have a Lyman filament extruder kit and have had similar issues before. I haven’t solved them entirely, but I’ve done a number of prints using recycled ABS (mostly more prusa i2 parts).

The things that helped me the most:

1) I switched out my j-head extruder for a cheap geetech from ebay, and drilled out the nozzle diameter to a whopping 1mm. My nice extruder kept jamming because metal shavings showed up multiple times in the filament, and were too large to be extruded. Changing to 1mm has entirely solved that :). It’s pretty bad for detail though, so maybe I might try to get one drilled out to 0.75mm someday.

2) I lowered the filament extruder’s temperature and added a very slow fan aimed at the nozzle. The key to getting a more consistent extrusion diameter for the filament is making sure the filament hardens as soon as it comes out from the extruder. You need it to be pretty much solid as soon as it leaves the nozzle because otherwise any sort of movement makes for a unstraight and/or stretched filament. Having the low temperature also prevents it from expanding right out of the nozzle when running it at more than the lowest of tolerable speeds. (I guess it’s called die swell?)

3) Lowering my print speeds to about 20mm/sec.

Be aware that I’m using injection-molding ABS as opposed to extrusion ABS because that’s the type of regrind that I bought, so some of this might not help. But I’ve thrown in cut up bad prints into the mix and it hasn’t change much.

I may try to print and build me a 2nd printer so that I have one with a nicer nozzle for fresh ABS and a 2nd one for recycled ABS. But in the meantime, it’s been an interesting adventure.

[Luuk]

Hey @hachu!

Thanks for sharing your experiences! I think point 2 can definitely make a change. Regarding swapping out the nozzle; this defeats the purpose in my opinion. I want our Filabot to complement our Ultimaker, not limit it

Cheers,