Diamond Hotend Opens The Color Gamut For 3D Printing

It’s safe to say we’ve hit a bit of a plateau with hobby based 3D printers using FDM technology. Print quality is pretty high, they’re about as fast as they’re going to get, and compared to commercial machines they’re a pretty good bang for your buck. So what’s next? What about printing in color?

diamondhotend-1It is possible to print in color using a regular 3D printer and a bit of patience, but it’s really not economical or efficient. We’ve seen multiple extruder heads for 3D printing as well, but there are many problems with that due to calibration and trailing plastic from one head to another. So what if you could feed multiple color filaments into a single mixing head?

Well, it turns out you can. Earlier this year RepRap ran a Kickstarter for the development of the Diamond Hotend —  a single nozzle multi-color extruder. It’s in production now and appears to work quite well. It’s also compatible with many 3D printers as long as the motherboard has triple extruder support.

However, the big question remains — how do you program a colored print? Using Repetier Host actually. You’ll need to export your 3D model in the .AMF file format, but once you do, you’ll be able to configure it for a color print job inside Repetier Host.


Alternatively, you can print everything out in a single color, and then use a hydrographic printing technique to put full color images on your prints…

[via Gizmag]

53 thoughts on “Diamond Hotend Opens The Color Gamut For 3D Printing

    1. Horrible video,
      Blatant profiteering off a non-profit organisation (he introduced himself from “rep rap” not “reprap.me”)
      Misleading statements about couloir changing filament
      No second-material support
      Not full-colour, only Tri-colour
      Mounting option not well seen.

      This is basically a 3-in-1 nozzle adapter for E3D nozzles.

      1. I don’t understand how people manage to window box their video like that. Strikes me as blitheringly incompetent. I’m surprised they managed to avoid portrait video.

        The sound is horrible. Is it really that hard to buy or borrow a cheap lav mic system?

      2. I think I understand some of that though. Color mixing requires changes at most steps in the work flow. The firmware probably needs new code to support it. As yet, few slicers support AMF file format to get color support, few of those support color gradients, or at least more than a very small number of colors (like more than 4). The ex-botObjects CubePro C might be the only one so far, and that’s locked up proprietary.

        Whether this nozzle can avoid the “toothpaste” effect that Richard Horne has discovered in his own design is another question. The botObjects machine uses a mixing screw.

      3. >Not full-color, only Tri-color

        This is one of the things I find disappointing about this print head. They have no example of mixing colors, and from what I’ve read on actual reprap about mixing attempts, it probably wouldn’t work very well if you tried.

        Not only that, but the RGB filament being fed into it is VERY misleading. Even if this thing were capable of mixing filaments, if you tried it with RGB filament then the result would be very muddy blackish colors at best. RGB color systems work well for computer screens and lights, but in objects (and paints) you need a CMYBW system, with Cyan, Magenta, Yellow, Black, and White. This is required for full-color prints in FDM, but is obviously more of a technical challenge, requiring the mixing of five different strands of filament. (and getting them to the print head in the first place in one piece)

        1. You might be able to get away without black (like my old Lexmark inkjet that would happily print black and white documents without a black cartridge). But you might want to include transparent.

          I doubt that mixing 5-6 filaments is the best way to go about full colour FDM prints though. I think print some sort of transparent filament and then inkjet on the colour during/after each layer.

          1. Transparent… good call. However many colors are necessary to get full color printing I would add one more filament too… water soluable! For easy-disolving support structure. So.. CMYBW + Transparent + water soluable… the ‘perfect’ printer has to be able to use 7 filaments!

      4. Yes I know that the video is horrible but we are technicians not fancy design film makers.

        The information in this article is from when we had our Kickstarter campaign back in april and a lot have happened since.

        No second-material support?
        Red / black PLA and PVA
        We are also working on a direct drive for flex filament.

        Not full-colour, only Tri-colour?
        Please have a look at these videos:

        Mounting option not well seen?
        There are hundreds of different 3D printers and variations thereof and we just can’t make mounts for all of them But you can download the bacik mount from Thingiverse and adapt it to our printer.

        And we are working on mounts / kits for the 10 most popular 3D printers (Ultimaker 1 and 2, Makerbot Replicator 2 / Wanhaou Duplicator 4, bq Witbox and bq Prusa i3 Hephestos.. more to come…)

        1. While the mounting was a pretty petty complaint, I still wouldn’t argue that’s ‘full color’ exactly. It’s better, for sure, (you could DEFINITELY get grayscale, even grayscale mixed with one other color) but it’s not full color in the same sense as printing a color photo of someone onto the surface of an object. You can put different colors in, and you can blend them, but you don’t have full control in the sense that you can put out any color you want on a whim.

      5. Yes I know that the video is horrible but unfortunately we are only mortal makers and not god like video instructors but please don’t let our incompetence in filmmaking take your focus away from the subject in the article and please don’t bring out your grammar nazi because then I will be truly doomed….

        This article is a repost of a 6 month old article from Gizmag and it does not contain all the information there is about the Diamond Hotend.

        So I take it that your critique is based on your first impression from the article and the “horrible” video?

        What do you mean about “Misleading statements about couloir changing filament”

        No second-material support??
        Here is a picture of red / black PLA and PVA:
        And we are working on a direct drive solution for flex filament.

        Not full-colour, only Tri-colour??
        Please have a look at these videos (that I also made “horrible” by myself)

        Mounting option not well seen??
        There are hundreds of different 3D printers and variations thereof and we simply can’t make mounts for all of them but please don’t let that stop your inner maker just go to Thingiverse where you can download the basic mount and model it so it fits your printer:

        You are also welcome to join our FB user gruppe where you can see what some of our users have made with their Diamond Hotends

          1. No we are not RepRap.org but we like to see ourself as a part of it and we have contributed with our ovn open sorce projects like:
            The Easy Stepper: http://reprap.org/wiki/Easy_stepper
            The Power Expander: http://reprap.org/wiki/Power_Expander
            The Stepper Expander 1,2 and 3: http://reprap.org/wiki/Stepper_Expander
            The Diamond Hotend is also Open source and available on RepRap.org: http://reprap.org/wiki/Diamond_Hotend
            And as far as I know we were also the first makers of ALU. heatbeds back in Aug. 2013

            In daly speak in the office we just say reprap so we did not notice it, but since this is a apparently a big deal for a lot of people we will of course look into correcting this where possible.
            The video in this article has been copied by bolsoncerrado for Gizmag so unfortunately there isn’t much we can do about it in this case.

          1. “The video in this article has been copied by bolsoncerrado for Gizmag so unfortunately there isn’t much we can do about it in this case”

            You can annotate the video to put a disclaimer or something to make it clear.

  1. Has anyone tried on-the-fly dying of the filament? I’d have thought that’d be a neater solution, as you’d only require one supply of filament, and you’d be able to mix colours easily.

    1. I guess you’d need a good way of mixing it. Perhaps a tiny little tapered worm screw a bit like an ejection moulding machine. Perhaps the screw itself could be heated and hollow allowing the dye to be put through the screw and released from holes along it’s length.

    2. People have done it, there’s marker adapters out there to try it with little cost. The tries I’ve seen didn’t look impressive, and I don’t know if the marker dyes and solvents heated up like that.

    3. tried and with good results, but not excellent.
      You’d want white filament to do that, and permanent markers to as dye.
      Direct drive extruders and 1.75mm work better, and you must start dying before the color is needed, and stop before the color is not needed.
      Then color oozes and dyes also the inner parts of the extruder, so it’s possible to achieve a sharp white to blue transition, but as you stop dyeing the filament the color still remains for ~10cm of filament, so it paints a gradient from blue to white.
      It’s also impossible to achieve full color, as the inside of the filament is still white. The color however is more vivid than it is by painting the piece after the print and is permanent.

      In conclusion is good for rainbow vases, less boring boxes, color shifts on the z axis, but not suitable at all for text or details.

      1. I like the laser idea, what about rewritable dvds? They had some kind of dye which could be changed colour with a laser.
        Just need a few different dyes which operate at different frequencies or one whose colour depends on intensity of the lasering.

      2. You’d probably still want to use a CMYKW system for better color control. Remember that the particles of a particular color would be reflecting that color. So your RGB idea would not necessarily mean you just need 3 lasers, one red, one green and one blue.

        So the frequencies the particles absorb would not have to be the color of the dye. Although they could be. Hm. This will require some thought…

  2. it’s a good idea to mix 3 feeds in 1 nozzel, I’ve been thinking of this for some time and glad to see someone’s done it. I’ll forgive them for using the term reprap as long as their designs are open source and they allow others in the reprap community to make derivative nozzels. I find it hard to give these guys hassle while pretty much every consumer 3D printer on the market borrows heavily from the reprap project without attribution of any kind whatsoever. I wouldn’t be the least bit surprised if makerbot steal this 3 feed nozzel design for their next line of printers (not before adding a “smart” component that requires replacement so they can sell nozzels in packs of 3).

    1. Indeed, mixing red, yellow and blue inside the extruder could mean multicolor printing but for full color you also need white and black. So this is a nice step in the right direction, it just needs 5 feeds.
      I didn’t see it actualy mixing the feeds though they do mention a mixing Chamber.

          1. You can’t. In offset lithography, if you want white you use white ink (or use a white surface and not print in that area). For 3D printing (FDM), you’d need an additional white filament. Same goes for clear, or transparent.

        1. Chamb Onz makes the oops-forgot-that point that you don’t get white for free like you would on paper… so CMYW or CMYWK would be in order. You get a yucky black by mixing CMY in equal parts.

          Questions is, I’ve been wanting to experiment with CMY mixing, but nobody makes filaments in good cyan/magenta colors. I think the yellows I have would be sufficient – so why doesn’t anyone make cyan & magenta?

          I’ve seen goobers try to market RGB… reminds me of the any-color-pen Kickstarter.

      1. Well Apple has a patent on a rectangle with rounded corners so I don’t see why we couldn’t have gotten a patent on the Diamond Hotend?
        We chose to make the Diamond Hotend open source with the CC-BY-NC-SA license.
        Yes it’s the Non Commercial version of the license and that’s because we would like to get our investment in the Diamond Hotend back.

        1. CC-BY-NC is NOT Open-Source.

          The -NC clause is incompatible with Open-Source, Open-Hardware, and Libre-Hardware.

          Just because you show the files, doesn’t make it Open-Source, you have to *also* give certain freedoms to your users, and -NC is a way to take that freedom away.

          Do not call Open-Source things that are not.

          Also, do not tell people you are “Reprap” when you are just one amongst hundreds of “reprap parts sellers”.

  3. I actually have a Diamond Hotend and I rather like it. However, I haven’t been able to eliminate oozing and stringing (yet). Not sure if this is Diamond-related or something that all bowden extruders have, or just my own incompetence. I suspect, however, that there’s a set of parameters that produce better results than those I am currently getting. Anyone here printing successfully with the Diamond Hotend?

      1. Actually,
        The source of the problem is the extruder, the bowden only makes the problem worse. With the right extruder, it’s no longer an issue. I’ve used 1.3meter long bowdens and 12in bowdens with the same amount of retraction and without problems.

    1. I was just gonna link to that, well done kind sir.
      That said, didnt that turn out to need to be cleaned after every use? (plastic clogging up the ‘mixing chamber’)

      Either way, stil proofs these reprap.me guys have nothing new, albeit maybe its a bit nicer.

  4. I hope that they are better at engineering than they are at making videos, lol.
    I love printing with different colors and I hope someone will take on the slicer challenge: extruding leftover color on a tower.
    Maybe a trip to a brush to clean the tip.
    Also, perhaps the ability to change extruder temp quickly, so that I can change materials as well as color. Definitely need to retract PLA quite a ways before extruding ABS…

  5. I made a multi colour extruder that could have any number of colours.


    That is all that is left of it now. I lost interest once I got it working.

    It was a Bowden only thing. Two steppers, one to select the filament to push by rotating the drum until the chosen pulley lined up and another connected to the brass rod to actually push. One ptfe tube for each colour and at the other end of the tube was a 2 inch stainless tube with a nozzle. The heater accepted the nozzle from above and heated the stainless adn nozzle melting the plastic and to change colours you just removed the nozzle and put one of the others in. I never bothered making it all automatic but it would have been easy enough to do in the same way that CNC machines change tools. Once I proved that it was a valid way to do it I lost interest and I only print with one colour anyway.

    1. I have to say that thats a pretty sweet approach, you should at the very least get somebody to continue upon that.
      Also, may i ask why you lost interest/only print with one color anyway? do you use hydrographic prints now? paint? or do you just your imagination to give things color? :P

  6. for full color you need a mixing nozzle that does CMYKW, Printers get full color by doing CMYK and using the absences of ink for W, but you cant have an absence of plastic be you lightening agent. E3D has looked into this, it is really difficult.

    Also this is a rip off of the E3D hot end.

    1. It’s not a ripoff at all, the heatsinks come from E3D, and are included in the kit. E3D provides these to reprap.me, who then package it in with the diamond. They do not at any stage claim the heatsinks are their design. The diamond hotend design is just a brass cone with some holes in it. Fairly easy to manufacture, and not especially special. I’d be more interested in something like the Tri hotend by Generic Default on SeemeCNCs forums, or the Kraken from E3D, however neither can do full color. OTOH, I’ve seen a 5 extruder printer at one point, although it did not have a mixing nozzle. If you wanted a 5 color mixing nozzle, it would be a fairly massive beast, as you would need to fit an entire heatbreak, heat sink, and bowden connector into 72 degrees of arc, while maintaining enough air flow to cool it. But, you would have trouble doing sharp color changes, due to the need to purge other plastics. If you took slightly more care than this design, the weight could be decreased, but the machining time and complexity would grow dramatically (4 axis milling required for the outer profile, to do what I have in mind) And that’s not even getting into adding metallic, or clear elements. Colors are hard, and the need to do color mixing on 3D printed projects is very low (if it needs to look pretty, then paint it). Post processing will kill your color choices pretty quickly (Acetone would make them blend and run, as would many coatings), and there is no mechanical advantage.

    2. We are using the original E3D so I don’t see how we are ripping them of?
      But I am happy to see that you are willing to defend the original creators and I do hope that you will do the same for us when it comes to the Chinese Diamond Hotend knockoffs with fake E3D heatsinks :)

  7. “It’s safe to say we’ve hit a bit of a plateau with hobby based 3D printers using FDM technology. Print quality is pretty high, they’re about as fast as they’re going to get”

    No, not by a long shot. I can see why people would think that, but there’s several hundred mm/s more that even we can achieve, and that’s before our new system is completed that will chop print times way down. Frankly, you haven’t seen nothing yet.

    Griffin 3d

  8. I was an early backer of this hotend, I haven’t had an opportunity to install it in a printer yet (You can see it unboxed here: http://media.makecoolthings.com/wp/2015/06/3dp_diamondunbox05.jpg) but I look forward to putting it into a delta controlled by my FastBot BBP 1S board. (Which was also a crowdfunded project.)

    I agree that the involved color models don’t offer much hope of true ‘full color’ printing in just three filaments, but I look at the range of possible applications more from the perspective of tackling the more mundane impossibilities, like loading one color, along with black and white, and using it to create sort of a single-color grayscale. Or mixing in a neutral clear filament. Or simply mixing a couple colors together to create a color you wanted but which isn’t available in filament. I’m also curious to see if it’s possible to mix varying percentages of flexible PLA and regular PLA on the fly to get varying degrees of flex.

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