Programmable Filament Gives Even Simple 3D Printers Multi-Material Capabilities
spectrum.ieee.org
spectrum.ieee.org
From what I've heard, there is a lot of filament waste still. But the results looks decent.
I once saw some video about the buffer and the way it is flawed - also don't expect any print speed if you're using it :S
https://youtu.be/G9ZdMgCMsV4?t=23
...with gigantic magazines!
Their support is completely unhelpful (I ended up reverse engineering the octoprint python plugin) and while its pretty piece of hardware, it is largely a very expensive paper weight as another commenter mentioned. Several design flaws make it very frustrating to find the right settings for material combinations since it clogs all the time, forget doing true multimaterial (not just multicolor) printing unless you make a binding layer (TPU) or chose compatible plastics since most stick together worse than PET, and the closed loop feedback mechanism is far from good enough to have even 50% success rate. I managed to get a few decent prints from the contraption but it required babying the 3d printer even more than before. If you have wild humidity or temperature swings (such as when doing a long 10-20 hour print), you can forget about any sort of reliability. Oh and it is slow - best I've gotten on the 2S is 40mm/s (one of the printers I tried it on maxes out at 200-300 mm/s, though few materials can support that speed).
That said, without that closed loop feedback, the method described in the paper simply will not work on nontrivial prints. If I'm understanding it correctly, it's just doing the same thing as the Palette except not in real time.
I know three people who own this, two think it works fine and one thinks it is junk. I have been tempted but haven't wanted to burn up $300 on the off chance it does what I would want.
My original Makerbot Creator 2x has two extruders so you can do two materials, but print failures where one of the filaments stripped were more common than print successes. It was why I didn't bother looking for a dual extruder when I replaced it and ended up with the Prusa MK3S (which basically had everything on it that I would have put into a printer I built myself).
Its in stark contrast with the Prusa printer itself which I find to be of extremely high quality an easy to use :).
I also have two friends who have the MMU. For one them it always worked perfectly. For the other friend the first one didn't work at all, but once Prusa replaced it with an orange one (they were very explicit about that) it did work a lot better.
I expect it also makes for some interesting print failures when you're print/filament registration is messed up. :-).
If this becomes a 'thing' then you could design a filament making machine that would make a custom spool of filament. Even if you had a printer with a 'belt' for the bed, then you could make as much filament as you wanted.
This is exactly what they are doing: see the video in the article.
If, of the end of that tread/surface you had a take up spool you could just print until you filled up the spool if you wanted too.
A better solution would be a machine that snips different color filaments right off the spools at the right lengths and welds them together. That all said, this is a cool project from a "what's possible" perspective.
I guess there might be a limit on the number of times material can be extruded from a hot end before it starts to degrade?
I noticed that some of the parts shown in the video appear to have a wipe tower next to them. Presumably this is because the G-code was generated with Cura or similar, but given that the filament is one continuous piece with colour changes in exactly the right places, it seems like you could skip the wipe tower? Or maybe it's better to keep the wipe tower because it reduces the precision required in priming the nozzle?
I suppose you could print filament of arbitrary length by doing batches that get pieced together.
Here's my best idea so far how to do it:
(1) Instead of a spiral, print in a double spiral. Meaning a spiral that starts on the outside, goes to the middle, makes a u-turn, and then goes out to the edge again. (For the u-turn, I assume filament has some minimum turn radius and as long as you stay above that, it's workable to straighten it out.)
(2) Pause printing, put a clamp over one end of the printed filament, yank the rest off the bed and wind it on a reel.
(3) Resume printing, and repeat as many times as necessary.
I cannot but imagine that besides the time needed to 3D pre-print the custom filament, the number of failed prints due to errors in the calculation, or the feeder slipping, or the extruder clogging must be relevant.
Never used one, but there are 2-in-1 and 3-in-1 cheap printers that surely are more practical.
On my printer, the extruder uses a toothed gear that grips the filament by biting into it. The exact length of filament that gets displaced for a given amount of gear rotation depends on how deeply the teeth penetrate, which in turn depends on how tightly the gear and filament are pressed together, the filament's stiffness, ambient temperature, and probably all kinds of other factors.
It seems to me that you could solve this problem in principle by printing a toothed pattern into the filament itself, so that the gear teeth automatically align it to the correct position, instead of deforming it.
3D printers can be very finicky, and I'd worry that the filament diameter and properties would be variable enough to cause issues here.
My impression is that multi-color printing is far more limited by the amount of effort one is willing to spend on tuning everything until it works than just money.
Maybe also more high precision because you can have the extruder closer to the printer, to match filament type with what is printed at any given time.
I proposed the this technique about 5-6 years ago here on HN. Nice to now se it in real life.
[1] https://www.filastruder.com/products/filastruder-kit?variant...
The article addresses this but I don’t understand their explanation.
In this method you have to only switch to each color once (if the filament length you can print is enough for your object).
In a real object your print is 3D and consists of layers that are ~ 0.1-0.2mm high. In a typical multicolor print each layer has several colors, and you have to finish a layer before printing the next one. So you have to switch between all colors that are present in each layer.
For making relatively small, multi-material / multi-color prints, this really is a pretty clever system that looks reasonably practical on a wide variety of existing low-end 3D printers. With good software support, I could imagine being able to make things with interesting physical properties by making hybrid rigid / flexible materials (integrated hinges or other deformable parts, for instance).
This is what I wasn’t getting:
> resets the z-axis back to 'layer 0' each time it switches colors