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Fast desktop-scale extrusion 3D printing

185 points by lainon 9y ago

blincoln 9y ago
If it incorporates a gantry design and a laser powerful enough to melt plastic, how hard would it be to make it a multipurpose 3D printer/2D (+depth) laser cutter? Getting two useful tools for the price (and space) of one would make this an easy sell to me, at least.
- lucaspiller 9y ago
  Take a look at machines like the HyperCube which are attempts at a generic CNC machine with swappable tools/print heads. https://www.thingiverse.com/thing:1752766 https://www.thingiverse.com/thing:1752766
mwrouse 9y ago
There is absolutely no way that video is in real time. What kind of servos are they using?
- jstanley 9y ago
  This kind of 3d printer generally uses stepper motors, not servos. From what I can see, this printer appears to use stepper motors too. I'd believe it's real-time. The X axis is held in place vertically by the 2 shiny metal rods you can see, and is dragged back and forth by the black rubber belt, which is controlled by a stepper motor.
  - mwrouse 9y ago
    I know, I have several printers mtself. They are using only servos. Which is why it's faster probably. EMJ-04 series. The rate at which it jumps around is just ridiculous though.
  - lylecheatham 9y ago
    They're actually using servo motors! They refer to it as a "servo-driven parallel gantry system" in the abstract.
- melling 9y ago
  The title says (in real time)
- sallyfour 9y ago
  Might be brushless motors and encoders
- fiter 9y ago
  My favorite ridiculously fast machines are wire bonders: https://m.youtube.com/watch?v=t4Jn7wVI3LU https://m.youtube.com/watch?v=t4Jn7wVI3LU
  - pimlottc 9y ago
    Wire benders are pretty cool too: https://www.youtube.com/watch?v=j-gabeEJ7EE https://www.youtube.com/watch?v=j-gabeEJ7EE
- jdietrich 9y ago
  By commercial CNC standards, it's not especially fast. Have you ever seen a pick-and-place machine in action? https://youtu.be/ylk6VMBLrvM?t=3m54s https://youtu.be/ylk6VMBLrvM?t=3m54s
- leon_sbt 9y ago
  It looks like they are using either a CoreXY or H-bot based design. Nice thing about those designs, is that you don't need to accelerate the motors/wiring back and forth. Giving better acceleration rate per unit of motor. The downside with those systems, is that they tend not to be stiff (due to large amounts of belting), or react to external forces well. That (H-bot/Core-XY) design would be poor for a convention CNC router, that has to react the forces associated with conventional machining. But for this application, it doesn't matter. The forces acting on an extruder are basically non-existent, with the exception of (the mass of the extruder * its designed acceleration rate). For going that fast real time, it might have some trick servos, or a hybrid motor (Search for Technic ClearPath Motors). If you like that video, then you might like this one. https://www.youtube.com/watch?v=NgGiu_0x7tg https://www.youtube.com/watch?v=NgGiu_0x7tg (Note: Not afflilated with that company, just like the video)
QAPereo 9y ago
Very cool, but big caveats as usual from a uni press piece. However, they ran up against a small glitch in their speedier design: The extruded plastic is fed through the nozzle at such high forces and temperatures that a printed layer can still be slightly molten by the time the printer is extruding a second layer. “We found that when you finish one layer and go back to begin the next layer, the previous layer is still a little too hot. So we have to cool the part actively as it prints, to retain the shape of the part so it doesn’t get distorted or soften,” Hart says. That’s a design challenge that the researchers are currently taking on, in combination with the mathematics by which the path of the printhead can be optimized. They will also explore new materials to feed through the printer.
- jstanley 9y ago
  > So we have to cool the part actively as it prints, to retain the shape of the part so it doesn’t get distorted or soften This is a (solved-ish) problem even on current-generation commercial printers. It's called a "part-cooling fan". It sits next to the hot-end and blows air on the plastic as it comes out of the nozzle. Here's a dual-fan example: http://www.akeric.com/blog/wp-content/uploads/2015/07/filamentCooler2.jpg http://www.akeric.com/blog/wp-content/uploads/2015/07/filame...
  - QAPereo 9y ago
    Apparently it can’t scale up 10x or more though, at least with current materials.
    - deelowe 9y ago
      Could this be solved by adding refrigeration? Couldn't they run the machines much faster if it was printing in a colder environment?
      - valine 9y ago
        It probably depends on what material you’re printing with. Keeping ABS from warping in a cold environment would be difficult or even impossible. At the very least it would put new limitations on what shapes are possible to print and constrain your options when it comes to infill.
cdancette 9y ago
It moves fast, but it still has to melt and apply the plastic, and it seems harder to make this part go 10x faster
- JamesUtah07 9y ago
  > The key to the team’s nimble design lies in the printer’s compact printhead, which incorporates two new, speed-enhancing components: a screw mechanism that feeds polymer material through a nozzle at high force; and a laser, built into the printhead, that rapidly heats and melts the material, enabling it to flow faster through the nozzle. That's the exactly what is making this new 3D printer 10x faster
  - LeifCarrotson 9y ago
    > a screw mechanism that feeds polymer material through a nozzle at high force Practically all existing 3D printers have this. The laser does seem novel - most use an electrically heated head nozzle to melt the plastic like a hot glue gun - but I remain skeptical when they list screw feed as an innovative ceature.
    - jaclaz 9y ago
      >Practically all existing 3D printers have this. No, usually they have a rotary feeder, i.e. "pinch-wheel", it seems like what they propose is a screw feeder, likely a screw with the axis roughly in the same direction as the filament, with "higher grip" on the filament, but probably it depends also on the specific filament material: >"In most desktop 3-D printers, plastic is fed through a nozzle via a “pinch-wheel” mechanism, in which two small wheels within the printhead rotate and push the plastic, or filament, forward. This works well at relatively slow speeds, but if more force were applied to speed up the process, at a certain point the wheels would lose their grip on the material — a “mechanical disadvantage,” as Hart puts it, that limits how fast the printhead can push material through. Hart and Go chose to do away with the pinchwheel design, replacing it with a screw mechanism that turns within the printhead. The team fed a textured plastic filament onto the screw, and as the screw turned, it gripped onto the filament’s textured surface and was able to feed the filament through the nozzle at higher forces and speeds. "
jaclaz 9y ago
"Finally, they devised a high-speed gantry mechanism — an H-shaped frame powered by two motors, connected to a motion stage that holds the printhead." It seems a CoreXY or H-bot design, I always believed that the issue with this design (like any cartesian design) is with the limits of acceleration and "drag" of (relatively) massive parts, particularly because the X and Y axis have not the same weight/mass when changing orientation of the movement (the Z is less of a problem, at least with "large" surface prints, the issue here is only around precision), and that was the reason why Delta's are usually faster. Maybe a Delta with that head/printing gear can move even faster ...
- coredog64 9y ago
  My wife has several Delta and XY printers. The deltas are much faster, but they're also much more "fiddly".
  - virtualritz 9y ago
    Could you define "fiddly" in this context, please?
    - hexane360 9y ago
      Harder to calibrate, mostly. In a CoreXY printer you can calibrate the X and Y axes more or less independently. In a delta you have to take several points to get exact values for arm lengths and therefore a solution to the mechanism.
  - Animats 9y ago
    Here's Naomi Wu's delta 3D printer mod. She mounted one on a backpack carrier frame, powered it with batteries, and walked around Shentzen while 3D printing.[1] This one isn't "fiddly" at all. [1] https://www.youtube.com/watch?v=i-ksb-gzfyE https://www.youtube.com/watch?v=i-ksb-gzfyE
- sigstoat 9y ago
  > It seems a CoreXY or H-bot design, I always believed that the issue with this design (like any cartesian design) is with the limits of acceleration and "drag" of (relatively) massive parts there are enormous multi-ton machines which can move faster than tiny little delta printers. delta printers are good at maximizing speed when you have constraints like price, noise, weight, "fits in my home", "uses single phase residential power" and "cannot literally tear my limbs off". don't confuse the constraints of consumer printers with the constraints of industrial machinery, which is what it looks like these folks are trying to design.
marcosscriven 9y ago
I’d like to see some close ups of the prints. In the video you can see the print bed vibrating like crazy, and each layer can’t be anywhere near solid if there’s a tenth of the time to cool, even with a fan. I wonder if you could have a something that squirts a fine jet of liquid nitrogen, just behind the print head? Expensive though I suppose.
- jaclaz 9y ago
  >I wonder if you could have a something that squirts a fine jet of liquid nitrogen, just behind the print head? Expensive though I suppose. Maybe - just a semi-random idea, mind you - a Ranque-Hirsch (or Vortex) tube (and a source of compressed air) would be enough and possiby be more practical: https://en.wikipedia.org/wiki/Vortex_tube https://en.wikipedia.org/wiki/Vortex_tube
  - louithethrid 9y ago
    Add Peletier elements to that, cooling the air to cool, heating the filament to print.
- lbotos 9y ago
  Also though depends on the need right? If I'm making a 3-d print of something that I just want to see a very rough mockup in space, I might trade accuracy for speed if it goes from an hour to < 10 min.
  - jaclaz 9y ago
    >Also though depends on the need right? If I'm making a 3-d print of something that I just want to see a very rough mockup in space, I might trade accuracy for speed if it goes from an hour to < 10 min. Yep, coincidentally I was just reading today about a "crazy" experiment increasing "abnormally" the nozzle hole size on a common printer, JFYI: http://www.tridimake.com/2013/07/extremely-fat-extrusion-with-1-mm-nozzle.html http://www.tridimake.com/2013/07/extremely-fat-extrusion-wit... of course having both speed and precision would be much better.
wheresmyusern 9y ago
this is absolutely brilliant. i have no idea how nobody thought of this before. it was so obvious, just melt the plastic faster. so blindingly obvious. i have personally spent many hours trying to design a faster printer. its encouraging to know that there was a very elegant solution right under my nose the whole time. maybe there are a few more?
- tfolbrecht 9y ago
  If you think that's a great idea, how about this one: Melt the plastic even faster than that. I'll be expecting my check in the mail.
  - richk449 9y ago
    No! No, no, not 6! I said 7. Nobody's comin' up with 6. Who makes prints in 6 minutes?
    - ralusek 9y ago
      Actually most printers can make it all the way up to 10. The one I've got at home heats at 11; one hotter.
- rateofchange 9y ago
  This isn't a new idea at all. It's just getting a lot of publicity.
schpaencoder 9y ago
In the mid 1980 there was a similar craze related to dot-matrix printers and their cps (chars per second, or how fast they were). Then laser printers became cheap and everyone forgot about the dot-matrix. I guess this is the same thing. Fast forward 15 years.
- gh02t 9y ago
  Probably the next revolution in 3D printing speed will be something that prints an entire object at once, maybe via some sort of science fiction style hologram illuminating a resin. There are technologies that kinda resemble this on the cutting edge (like continuous liquid interface production), but we are still really far away from that ideal. For the foreseeable future we are probably doomed to incremental improvements.
  - vbuwivbiu 9y ago
    It's probably possible to create a "matter hologram": we already know we can put molecules as large as C60 in quantum superposition. If we could create a coherent source of such molecules and pass them through a beamsplitter and suitable modulator (to shift their phase), combining the two beams, we could create an interference pattern in free space which would reify the object, like the replicator in star-trek.
    - gh02t 9y ago
      The nicest thing about our mythical hologram printer is that supports would be unnecessary for stuff like overhangs and you could maybe even print complex internal structure, depending on just how capable your 3D hologram was. One can dream...
      - vbuwivbiu 9y ago
        I think we should rename our mythical printer from "hologram" (which implies replay) to "quantum interference printer"
wheresmyusern 9y ago
what are the problems with printers today? for hobbyist extrusion printers? - they are slow (fixed). but even 10x leaves something to be desired. - they cant print all shapes elegantly. for many shapes you need scaffolding. its a nuisance. - they are course. print layers, even at the thinnest settings, are still rather thick. also, there is a lot of inconsistency, stringing and surface imperfections. find a way to solve these problems in a relatively cheap printer and we might actually see the revolution that was talked about when 3d printing first arrived.
- bunderbunder 9y ago
  Two others: They are big, and they are expensive. That makes owning a 3D printer something that still doesn't make a lot of economic sense for me. I'm not certain it ever will. I'm waiting for the equivalent of a Kinko's for 3D printing. That will make 3D printing much more accessible to me, and I assume it would also get me access to 3D printers that can do much higher quality work than the at-home models are capable of.
  - gh02t 9y ago
    > I'm waiting for the equivalent of a Kinko's for 3D printing A lot of universities offer this to their students already. Commercially, off the top of my head, Staples and the UPS store have some 3D printing services available at a limited number of stores but I don't think it has been terribly successful. Problem is, 3D printing is IMO not much more than a novelty unless you are designing your own parts, but then iterating on a custom design is painful and expensive with a commercial service. I use my 3D printer a ton, both for work and for hobby stuff, and it usually takes a few tries to get a design right. That's hard to do sitting in a store or by mail and typical markup for those services is like 10-20x actual cost. It quickly gets expensive enough that buying your own printer starts to make sense, especially when quality printers can be had for <$500 nowadays and quite serviceable printers for <$200. There's really not a huge difference in quality between the higher end printers and the good examples of the affordable ones (at least, comparing FDM printers to their kin, SLA/DLP is a different beast entirely). Most of the difference is in convenience and secondary features like dual extrusion or self-leveling.
The_Double 9y ago
Link to the paper for those interested: http://www.sciencedirect.com/science/article/pii/S2214860416303220 http://www.sciencedirect.com/science/article/pii/S2214860416... edit: Arxiv link: https://arxiv.org/abs/1709.05918 https://arxiv.org/abs/1709.05918
tfolbrecht 9y ago
And if reliability is an issue, just stick another print head on to print a backup print in tandem. Can I be accepted into MIT now?
janoc 9y ago
[deleted as completely wrong - don't write posts before having coffee! Mea culpa!]
- lexicality 9y ago
  That article describes a completely different university and a different acceleration technique
Ccecil 9y ago
The main benefit to the speed will be realized when they scale the build area of the machine. As I suspect they realized it is difficult to get past the physics of the plastic cooling without causing other issues (delamination, warping, etc). The gain will be largely noticed when they are printing with this extruder using a build area larger than 1m cubed. The issue on large printers is being able to get the newly deposited material down while the previous layer has not cooled too much (delamination), although, this can be can be partially controlled with things like heated build chambers and such...they are patented. This idea was tossed around in #reprap for a few years (I know I have heard the idea thrown out there) and I am glad to see someone working on it. Although, I disagree that a screw drive is needed. I use hobbed gearwheel drive on my extruders and rarely is the issue the hobb slipping. Typically, it is the motor stalling instead. This isn't so much a product of the drive wheel/extruder as it is the hotend not being able to keep up with the commanded extrude volume...since this hotend doesn't have that issue (or so it seems) I suspect the conventional extruder could be used with just a modification to hotend/heater design. Once the commercial 3d printing market moves up to things like servos, encoder feedback, etc. I suspect the speeds of things will start ramping up greatly. The issue isn't so much the tech but the cost...people are cheap. edit: After reading the linked arxiv page. I see they are using closed loop servo motors/drivers and a RAMBO controller. They could go faster if they used a 32 bit controller like a smoothieboard or duet instead of the 8bit "arduino based" controllers. {Not saying RAMBO is a bad board, they are known to be very reliable for OEMs} Not to mention that Smoothieware has the control modules for lasers and cnc built in as well as the 3d printer so it requires probably no firmware modification to get this running...just config and maybe a custom bin. (Disclaimer: I work directly with the Smoothie project so I may be biased)
- lylecheatham 9y ago
  > Although, I disagree that a screw drive is needed. I use hobbed gearwheel drive on my extruders and rarely is the issue the hobb slipping. Typically, it is the motor stalling instead. Although that may be the problem on your printer, it's simple to fix because one can always add a larger motor. The problem that they solved is that eventually, a stronger motor won't cut it because the hobbed gear will slip, and that's what this paper is all about. Optimizing the motor is done by just upscaling it, but optimizing the drive is what made them to move away from the existing hobbed gear setup. > They could go faster if they used a 32 bit controller like a smoothieboard or duet instead of the 8bit "arduino based" controllers. {Not saying RAMBO is a bad board, they are known to be very reliable for OEMs} I would actually predict a minimal increase in speed. 32-bit controllers don't make for inherently fast printers, they allow for it if utilized properly. What you'll find though is that Marlin and Smoothie both use the GRBL planner under the hood, and generate very similar output. The only major difference I noticed in the output between the two is that Smoothie generates smoother (hence the name) step waveforms. I guess you can also generate steps at a higher frequency with smoothie, but you should be careful equating higher step frequencies with higher speeds, when most of the time people are running with microstepping settings. Higher frequency allows you to get more dynamic range between speed and precision, but that's not really what the paper was about.
jseip 9y ago
The first person to put this (or equivalent) on Kickstarter is going to raise a lot of money.
Peter-W 9y ago
I'm impressed by the speed in the video, I thought it was sped up at first.
deleted 9y ago
[deleted]
Animats 9y ago
Pushing filament with a gear was never a good design; it was just something that hobbyists could build easily. Injection molding machines use a screw drive to push molten plastic. This new machine uses a scaled-down version of the injector screw of an injection molding machine. Design and manufacture of injection molding screws is complicated but well understood.[1] They're not easy to machine, but that's what CNC mills and four-slide machines are for. It's like making a drill bit, something that's done industrially millions of times a day but is very tough for hobbyists. I'd wanted to use a laser for heating in a 3D printer, but not to heat the plastic being deposited. The fundamental problem with filament-type 3D printers is that you're welding a hot thing to a cold thing. That never works very well. That's what causes cold solder joints and weak welds in metal. In 3D printing, it's why the bonds between layers are much weaker than the plastic's inherent tensile strength. I wanted to have a small laser (about 10W) aimed ahead of where the filament is being deposited, to heat up the material already placed. That way, both sides are hot as the weld occurs, which should yield a much better weld. This is what the heated build plate and heated build chamber designs are trying to accomplish, but they're not putting the heat the one place it's really needed. As lasers in the 10W range become more affordable, this looks like a better idea. A few years ago, it was an insanely expensive idea, but now, you can get 10W for about $300. [1] https://www.plasticsportalasia.net/wa/plasticsAP~zh_CN/function/conversions:/publish/common/upload/technical_brochures/TI_Screwdesigns.pdf https://www.plasticsportalasia.net/wa/plasticsAP~zh_CN/funct...
- cptskippy 9y ago
  Heated build plates and enclosures are primarily to prevent the part from warping and pulling itself off the build plate. The problem with trying to bond two hot layers together is that they distort. Typically the previous layer has not solidified enough and so most printer employ a cooling fan to lower the temperature of the previous layer, not raise it. It's very hard to find the right balance of extrusion temperature, fan speed, feed rate, and a myriad of other factors that affect print quality. Honestly your comment makes me think you've never actually used an FDM printer.
  - jstanley 9y ago
unlimitedbacon 9y ago
"The team identified three factors limiting a printer’s speed: how fast a printer can move its printhead, how much force a printhead can apply to a material to push it through the nozzle, and how quickly the printhead can transfer heat to melt a material and make it flow." None of these are the actual limiting factor on print speed. Many 3D printers are capable of traveling at 300 mm/s, and extruding at more than 100 mm/s, yet in practice the fastest parts of a print are usually done at 60 - 80 mm/s. This is because the faster you try to go, the worse the print quality is. The outer shells of a print, where quality is most important, are usually done at 30 mm/s. Quality 3D printing is all about maintaining a delicate thermal balance. You want the plastic to cool to below it's melting point (if it has one) as soon as it leaves the nozzle so that it hardens and maintains it's shape. However you also want to keep it warmer than it's glass transition temperature in order to combat the effects of thermal contraction. As you try to go faster the soft plastic will get dragged around harder and will have less time to cool. The layer below will be softer when the layer above is being deposited on top of it. This causes sharp corners to get rounded off and overhangs to curl upwards. The article does not have any close up shots of the objects printed on this machine, but I expect that they are pretty rough. As QAPereo pointed out, the article mentions that they ran into this problem. This does not mean that this is a bad idea, though. Products like E3D Volcano and the Lulzbot Moarstruder have proven that there is a niche in the 3D printing marked for fast sloppy printing. Another thing that they don't talk about is how this extruder deals with retraction. One nice thing about gear driven extruders is they give you very precise control over how much plastic is being put out. You can also quickly retract the filament a bit to drop the chamber pressure and minimize plastic leaking from the nozzle as it travels from one part of the print to another. I'd like to know how well the auger is able to do this.
- lylecheatham 9y ago
  Checkout the second to last page for pictures: https://arxiv.org/abs/1709.05918 https://arxiv.org/abs/1709.05918 I think you bring up a good point about the lack of precision at high speed. I think the next big thing in this industry is going to be diving into the factors behind the 'sloppyness' you mention. > I'd like to know how well the auger is able to do this. I can answer this one! it's actually more like a nut on a bolt, instead of an auger, meaning it can reverse just fine.

185 points by lainon 9y ago

If it incorporates a gantry design and a laser powerful enough to melt plastic, how hard would it be to make it a multipurpose 3D printer/2D (+depth) laser cutter? Getting two useful tools for the price (and space) of one would make this an easy sell to me, at least.

lucaspiller 9y ago
Take a look at machines like the HyperCube which are attempts at a generic CNC machine with swappable tools/print heads. https://www.thingiverse.com/thing:1752766 https://www.thingiverse.com/thing:1752766

mwrouse 9y ago

There is absolutely no way that video is in real time. What kind of servos are they using?

jstanley 9y ago
This kind of 3d printer generally uses stepper motors, not servos. From what I can see, this printer appears to use stepper motors too. I'd believe it's real-time. The X axis is held in place vertically by the 2 shiny metal rods you can see, and is dragged back and forth by the black rubber belt, which is controlled by a stepper motor.
- mwrouse 9y ago
  I know, I have several printers mtself. They are using only servos. Which is why it's faster probably. EMJ-04 series. The rate at which it jumps around is just ridiculous though.
- lylecheatham 9y ago
  They're actually using servo motors! They refer to it as a "servo-driven parallel gantry system" in the abstract.
melling 9y ago
The title says (in real time)
sallyfour 9y ago
Might be brushless motors and encoders
fiter 9y ago
My favorite ridiculously fast machines are wire bonders: https://m.youtube.com/watch?v=t4Jn7wVI3LU https://m.youtube.com/watch?v=t4Jn7wVI3LU
- pimlottc 9y ago
  Wire benders are pretty cool too: https://www.youtube.com/watch?v=j-gabeEJ7EE https://www.youtube.com/watch?v=j-gabeEJ7EE
jdietrich 9y ago
By commercial CNC standards, it's not especially fast. Have you ever seen a pick-and-place machine in action? https://youtu.be/ylk6VMBLrvM?t=3m54s https://youtu.be/ylk6VMBLrvM?t=3m54s
leon_sbt 9y ago
It looks like they are using either a CoreXY or H-bot based design. Nice thing about those designs, is that you don't need to accelerate the motors/wiring back and forth. Giving better acceleration rate per unit of motor. The downside with those systems, is that they tend not to be stiff (due to large amounts of belting), or react to external forces well. That (H-bot/Core-XY) design would be poor for a convention CNC router, that has to react the forces associated with conventional machining. But for this application, it doesn't matter. The forces acting on an extruder are basically non-existent, with the exception of (the mass of the extruder * its designed acceleration rate). For going that fast real time, it might have some trick servos, or a hybrid motor (Search for Technic ClearPath Motors). If you like that video, then you might like this one. https://www.youtube.com/watch?v=NgGiu_0x7tg https://www.youtube.com/watch?v=NgGiu_0x7tg (Note: Not afflilated with that company, just like the video)

QAPereo 9y ago

Very cool, but big caveats as usual from a uni press piece. However, they ran up against a small glitch in their speedier design: The extruded plastic is fed through the nozzle at such high forces and temperatures that a printed layer can still be slightly molten by the time the printer is extruding a second layer. “We found that when you finish one layer and go back to begin the next layer, the previous layer is still a little too hot. So we have to cool the part actively as it prints, to retain the shape of the part so it doesn’t get distorted or soften,” Hart says. That’s a design challenge that the researchers are currently taking on, in combination with the mathematics by which the path of the printhead can be optimized. They will also explore new materials to feed through the printer.

jstanley 9y ago
> So we have to cool the part actively as it prints, to retain the shape of the part so it doesn’t get distorted or soften This is a (solved-ish) problem even on current-generation commercial printers. It's called a "part-cooling fan". It sits next to the hot-end and blows air on the plastic as it comes out of the nozzle. Here's a dual-fan example: http://www.akeric.com/blog/wp-content/uploads/2015/07/filamentCooler2.jpg http://www.akeric.com/blog/wp-content/uploads/2015/07/filame...
- QAPereo 9y ago
  Apparently it can’t scale up 10x or more though, at least with current materials.
  - deelowe 9y ago
    Could this be solved by adding refrigeration? Couldn't they run the machines much faster if it was printing in a colder environment?
    - valine 9y ago
      It probably depends on what material you’re printing with. Keeping ABS from warping in a cold environment would be difficult or even impossible. At the very least it would put new limitations on what shapes are possible to print and constrain your options when it comes to infill.

cdancette 9y ago

It moves fast, but it still has to melt and apply the plastic, and it seems harder to make this part go 10x faster

JamesUtah07 9y ago
> The key to the team’s nimble design lies in the printer’s compact printhead, which incorporates two new, speed-enhancing components: a screw mechanism that feeds polymer material through a nozzle at high force; and a laser, built into the printhead, that rapidly heats and melts the material, enabling it to flow faster through the nozzle. That's the exactly what is making this new 3D printer 10x faster
- LeifCarrotson 9y ago
  > a screw mechanism that feeds polymer material through a nozzle at high force Practically all existing 3D printers have this. The laser does seem novel - most use an electrically heated head nozzle to melt the plastic like a hot glue gun - but I remain skeptical when they list screw feed as an innovative ceature.
  - jaclaz 9y ago
    >Practically all existing 3D printers have this. No, usually they have a rotary feeder, i.e. "pinch-wheel", it seems like what they propose is a screw feeder, likely a screw with the axis roughly in the same direction as the filament, with "higher grip" on the filament, but probably it depends also on the specific filament material: >"In most desktop 3-D printers, plastic is fed through a nozzle via a “pinch-wheel” mechanism, in which two small wheels within the printhead rotate and push the plastic, or filament, forward. This works well at relatively slow speeds, but if more force were applied to speed up the process, at a certain point the wheels would lose their grip on the material — a “mechanical disadvantage,” as Hart puts it, that limits how fast the printhead can push material through. Hart and Go chose to do away with the pinchwheel design, replacing it with a screw mechanism that turns within the printhead. The team fed a textured plastic filament onto the screw, and as the screw turned, it gripped onto the filament’s textured surface and was able to feed the filament through the nozzle at higher forces and speeds. "

jaclaz 9y ago

"Finally, they devised a high-speed gantry mechanism — an H-shaped frame powered by two motors, connected to a motion stage that holds the printhead." It seems a CoreXY or H-bot design, I always believed that the issue with this design (like any cartesian design) is with the limits of acceleration and "drag" of (relatively) massive parts, particularly because the X and Y axis have not the same weight/mass when changing orientation of the movement (the Z is less of a problem, at least with "large" surface prints, the issue here is only around precision), and that was the reason why Delta's are usually faster. Maybe a Delta with that head/printing gear can move even faster ...

coredog64 9y ago
My wife has several Delta and XY printers. The deltas are much faster, but they're also much more "fiddly".
- virtualritz 9y ago
  Could you define "fiddly" in this context, please?
  - hexane360 9y ago
    Harder to calibrate, mostly. In a CoreXY printer you can calibrate the X and Y axes more or less independently. In a delta you have to take several points to get exact values for arm lengths and therefore a solution to the mechanism.
- Animats 9y ago
  Here's Naomi Wu's delta 3D printer mod. She mounted one on a backpack carrier frame, powered it with batteries, and walked around Shentzen while 3D printing.[1] This one isn't "fiddly" at all. [1] https://www.youtube.com/watch?v=i-ksb-gzfyE https://www.youtube.com/watch?v=i-ksb-gzfyE
sigstoat 9y ago
> It seems a CoreXY or H-bot design, I always believed that the issue with this design (like any cartesian design) is with the limits of acceleration and "drag" of (relatively) massive parts there are enormous multi-ton machines which can move faster than tiny little delta printers. delta printers are good at maximizing speed when you have constraints like price, noise, weight, "fits in my home", "uses single phase residential power" and "cannot literally tear my limbs off". don't confuse the constraints of consumer printers with the constraints of industrial machinery, which is what it looks like these folks are trying to design.

marcosscriven 9y ago

I’d like to see some close ups of the prints. In the video you can see the print bed vibrating like crazy, and each layer can’t be anywhere near solid if there’s a tenth of the time to cool, even with a fan. I wonder if you could have a something that squirts a fine jet of liquid nitrogen, just behind the print head? Expensive though I suppose.

jaclaz 9y ago
>I wonder if you could have a something that squirts a fine jet of liquid nitrogen, just behind the print head? Expensive though I suppose. Maybe - just a semi-random idea, mind you - a Ranque-Hirsch (or Vortex) tube (and a source of compressed air) would be enough and possiby be more practical: https://en.wikipedia.org/wiki/Vortex_tube https://en.wikipedia.org/wiki/Vortex_tube
- louithethrid 9y ago
  Add Peletier elements to that, cooling the air to cool, heating the filament to print.
lbotos 9y ago
Also though depends on the need right? If I'm making a 3-d print of something that I just want to see a very rough mockup in space, I might trade accuracy for speed if it goes from an hour to < 10 min.
- jaclaz 9y ago
  >Also though depends on the need right? If I'm making a 3-d print of something that I just want to see a very rough mockup in space, I might trade accuracy for speed if it goes from an hour to < 10 min. Yep, coincidentally I was just reading today about a "crazy" experiment increasing "abnormally" the nozzle hole size on a common printer, JFYI: http://www.tridimake.com/2013/07/extremely-fat-extrusion-with-1-mm-nozzle.html http://www.tridimake.com/2013/07/extremely-fat-extrusion-wit... of course having both speed and precision would be much better.

wheresmyusern 9y ago

this is absolutely brilliant. i have no idea how nobody thought of this before. it was so obvious, just melt the plastic faster. so blindingly obvious. i have personally spent many hours trying to design a faster printer. its encouraging to know that there was a very elegant solution right under my nose the whole time. maybe there are a few more?

tfolbrecht 9y ago
If you think that's a great idea, how about this one: Melt the plastic even faster than that. I'll be expecting my check in the mail.
- richk449 9y ago
  No! No, no, not 6! I said 7. Nobody's comin' up with 6. Who makes prints in 6 minutes?
  - ralusek 9y ago
    Actually most printers can make it all the way up to 10. The one I've got at home heats at 11; one hotter.
rateofchange 9y ago
This isn't a new idea at all. It's just getting a lot of publicity.

schpaencoder 9y ago

In the mid 1980 there was a similar craze related to dot-matrix printers and their cps (chars per second, or how fast they were). Then laser printers became cheap and everyone forgot about the dot-matrix. I guess this is the same thing. Fast forward 15 years.

gh02t 9y ago
Probably the next revolution in 3D printing speed will be something that prints an entire object at once, maybe via some sort of science fiction style hologram illuminating a resin. There are technologies that kinda resemble this on the cutting edge (like continuous liquid interface production), but we are still really far away from that ideal. For the foreseeable future we are probably doomed to incremental improvements.
- vbuwivbiu 9y ago
  It's probably possible to create a "matter hologram": we already know we can put molecules as large as C60 in quantum superposition. If we could create a coherent source of such molecules and pass them through a beamsplitter and suitable modulator (to shift their phase), combining the two beams, we could create an interference pattern in free space which would reify the object, like the replicator in star-trek.
  - gh02t 9y ago
    The nicest thing about our mythical hologram printer is that supports would be unnecessary for stuff like overhangs and you could maybe even print complex internal structure, depending on just how capable your 3D hologram was. One can dream...
    - vbuwivbiu 9y ago
      I think we should rename our mythical printer from "hologram" (which implies replay) to "quantum interference printer"

wheresmyusern 9y ago

what are the problems with printers today? for hobbyist extrusion printers? - they are slow (fixed). but even 10x leaves something to be desired. - they cant print all shapes elegantly. for many shapes you need scaffolding. its a nuisance. - they are course. print layers, even at the thinnest settings, are still rather thick. also, there is a lot of inconsistency, stringing and surface imperfections. find a way to solve these problems in a relatively cheap printer and we might actually see the revolution that was talked about when 3d printing first arrived.

bunderbunder 9y ago
Two others: They are big, and they are expensive. That makes owning a 3D printer something that still doesn't make a lot of economic sense for me. I'm not certain it ever will. I'm waiting for the equivalent of a Kinko's for 3D printing. That will make 3D printing much more accessible to me, and I assume it would also get me access to 3D printers that can do much higher quality work than the at-home models are capable of.
- gh02t 9y ago
  > I'm waiting for the equivalent of a Kinko's for 3D printing A lot of universities offer this to their students already. Commercially, off the top of my head, Staples and the UPS store have some 3D printing services available at a limited number of stores but I don't think it has been terribly successful. Problem is, 3D printing is IMO not much more than a novelty unless you are designing your own parts, but then iterating on a custom design is painful and expensive with a commercial service. I use my 3D printer a ton, both for work and for hobby stuff, and it usually takes a few tries to get a design right. That's hard to do sitting in a store or by mail and typical markup for those services is like 10-20x actual cost. It quickly gets expensive enough that buying your own printer starts to make sense, especially when quality printers can be had for <$500 nowadays and quite serviceable printers for <$200. There's really not a huge difference in quality between the higher end printers and the good examples of the affordable ones (at least, comparing FDM printers to their kin, SLA/DLP is a different beast entirely). Most of the difference is in convenience and secondary features like dual extrusion or self-leveling.

The_Double 9y ago

Link to the paper for those interested: http://www.sciencedirect.com/science/article/pii/S2214860416303220 http://www.sciencedirect.com/science/article/pii/S2214860416... edit: Arxiv link: https://arxiv.org/abs/1709.05918 https://arxiv.org/abs/1709.05918

tfolbrecht 9y ago

And if reliability is an issue, just stick another print head on to print a backup print in tandem. Can I be accepted into MIT now?

janoc 9y ago

[deleted as completely wrong - don't write posts before having coffee! Mea culpa!]

lexicality 9y ago
That article describes a completely different university and a different acceleration technique

Ccecil 9y ago

The main benefit to the speed will be realized when they scale the build area of the machine. As I suspect they realized it is difficult to get past the physics of the plastic cooling without causing other issues (delamination, warping, etc). The gain will be largely noticed when they are printing with this extruder using a build area larger than 1m cubed. The issue on large printers is being able to get the newly deposited material down while the previous layer has not cooled too much (delamination), although, this can be can be partially controlled with things like heated build chambers and such...they are patented. This idea was tossed around in #reprap for a few years (I know I have heard the idea thrown out there) and I am glad to see someone working on it. Although, I disagree that a screw drive is needed. I use hobbed gearwheel drive on my extruders and rarely is the issue the hobb slipping. Typically, it is the motor stalling instead. This isn't so much a product of the drive wheel/extruder as it is the hotend not being able to keep up with the commanded extrude volume...since this hotend doesn't have that issue (or so it seems) I suspect the conventional extruder could be used with just a modification to hotend/heater design. Once the commercial 3d printing market moves up to things like servos, encoder feedback, etc. I suspect the speeds of things will start ramping up greatly. The issue isn't so much the tech but the cost...people are cheap. edit: After reading the linked arxiv page. I see they are using closed loop servo motors/drivers and a RAMBO controller. They could go faster if they used a 32 bit controller like a smoothieboard or duet instead of the 8bit "arduino based" controllers. {Not saying RAMBO is a bad board, they are known to be very reliable for OEMs} Not to mention that Smoothieware has the control modules for lasers and cnc built in as well as the 3d printer so it requires probably no firmware modification to get this running...just config and maybe a custom bin. (Disclaimer: I work directly with the Smoothie project so I may be biased)

lylecheatham 9y ago
> Although, I disagree that a screw drive is needed. I use hobbed gearwheel drive on my extruders and rarely is the issue the hobb slipping. Typically, it is the motor stalling instead. Although that may be the problem on your printer, it's simple to fix because one can always add a larger motor. The problem that they solved is that eventually, a stronger motor won't cut it because the hobbed gear will slip, and that's what this paper is all about. Optimizing the motor is done by just upscaling it, but optimizing the drive is what made them to move away from the existing hobbed gear setup. > They could go faster if they used a 32 bit controller like a smoothieboard or duet instead of the 8bit "arduino based" controllers. {Not saying RAMBO is a bad board, they are known to be very reliable for OEMs} I would actually predict a minimal increase in speed. 32-bit controllers don't make for inherently fast printers, they allow for it if utilized properly. What you'll find though is that Marlin and Smoothie both use the GRBL planner under the hood, and generate very similar output. The only major difference I noticed in the output between the two is that Smoothie generates smoother (hence the name) step waveforms. I guess you can also generate steps at a higher frequency with smoothie, but you should be careful equating higher step frequencies with higher speeds, when most of the time people are running with microstepping settings. Higher frequency allows you to get more dynamic range between speed and precision, but that's not really what the paper was about.

jseip 9y ago

The first person to put this (or equivalent) on Kickstarter is going to raise a lot of money.

Peter-W 9y ago

I'm impressed by the speed in the video, I thought it was sped up at first.

deleted 9y ago

[deleted]

Animats 9y ago

Pushing filament with a gear was never a good design; it was just something that hobbyists could build easily. Injection molding machines use a screw drive to push molten plastic. This new machine uses a scaled-down version of the injector screw of an injection molding machine. Design and manufacture of injection molding screws is complicated but well understood.[1] They're not easy to machine, but that's what CNC mills and four-slide machines are for. It's like making a drill bit, something that's done industrially millions of times a day but is very tough for hobbyists. I'd wanted to use a laser for heating in a 3D printer, but not to heat the plastic being deposited. The fundamental problem with filament-type 3D printers is that you're welding a hot thing to a cold thing. That never works very well. That's what causes cold solder joints and weak welds in metal. In 3D printing, it's why the bonds between layers are much weaker than the plastic's inherent tensile strength. I wanted to have a small laser (about 10W) aimed ahead of where the filament is being deposited, to heat up the material already placed. That way, both sides are hot as the weld occurs, which should yield a much better weld. This is what the heated build plate and heated build chamber designs are trying to accomplish, but they're not putting the heat the one place it's really needed. As lasers in the 10W range become more affordable, this looks like a better idea. A few years ago, it was an insanely expensive idea, but now, you can get 10W for about $300. [1] https://www.plasticsportalasia.net/wa/plasticsAP~zh_CN/function/conversions:/publish/common/upload/technical_brochures/TI_Screwdesigns.pdf https://www.plasticsportalasia.net/wa/plasticsAP~zh_CN/funct...

cptskippy 9y ago
Heated build plates and enclosures are primarily to prevent the part from warping and pulling itself off the build plate. The problem with trying to bond two hot layers together is that they distort. Typically the previous layer has not solidified enough and so most printer employ a cooling fan to lower the temperature of the previous layer, not raise it. It's very hard to find the right balance of extrusion temperature, fan speed, feed rate, and a myriad of other factors that affect print quality. Honestly your comment makes me think you've never actually used an FDM printer.
- jstanley 9y ago

unlimitedbacon 9y ago

"The team identified three factors limiting a printer’s speed: how fast a printer can move its printhead, how much force a printhead can apply to a material to push it through the nozzle, and how quickly the printhead can transfer heat to melt a material and make it flow." None of these are the actual limiting factor on print speed. Many 3D printers are capable of traveling at 300 mm/s, and extruding at more than 100 mm/s, yet in practice the fastest parts of a print are usually done at 60 - 80 mm/s. This is because the faster you try to go, the worse the print quality is. The outer shells of a print, where quality is most important, are usually done at 30 mm/s. Quality 3D printing is all about maintaining a delicate thermal balance. You want the plastic to cool to below it's melting point (if it has one) as soon as it leaves the nozzle so that it hardens and maintains it's shape. However you also want to keep it warmer than it's glass transition temperature in order to combat the effects of thermal contraction. As you try to go faster the soft plastic will get dragged around harder and will have less time to cool. The layer below will be softer when the layer above is being deposited on top of it. This causes sharp corners to get rounded off and overhangs to curl upwards. The article does not have any close up shots of the objects printed on this machine, but I expect that they are pretty rough. As QAPereo pointed out, the article mentions that they ran into this problem. This does not mean that this is a bad idea, though. Products like E3D Volcano and the Lulzbot Moarstruder have proven that there is a niche in the 3D printing marked for fast sloppy printing. Another thing that they don't talk about is how this extruder deals with retraction. One nice thing about gear driven extruders is they give you very precise control over how much plastic is being put out. You can also quickly retract the filament a bit to drop the chamber pressure and minimize plastic leaking from the nozzle as it travels from one part of the print to another. I'd like to know how well the auger is able to do this.

lylecheatham 9y ago
Checkout the second to last page for pictures: https://arxiv.org/abs/1709.05918 https://arxiv.org/abs/1709.05918 I think you bring up a good point about the lack of precision at high speed. I think the next big thing in this industry is going to be diving into the factors behind the 'sloppyness' you mention. > I'd like to know how well the auger is able to do this. I can answer this one! it's actually more like a nut on a bolt, instead of an auger, meaning it can reverse just fine.