A New Contender In Home Fabbing


Purple Crayon is a new entry into the home fabricating arena.  Shown above, with it’s makers [Konrad] and [Aaron], it’s set to compete with RepRap and Cupcake. It looks to be bigger than Cupcake, but smaller than the reprap. There aren’t many details available on their site, but we’re sure there will be soon. They do state that it should retail for less than $1,000.

30 thoughts on “A New Contender In Home Fabbing

  1. It can duplicate people? It obviously used different materials to construct the less hairy one, but they clearly share the same brain and the duplicate can make the same dorky hand gesture. Beware of clones!

  2. 1. common file formats are usually those that are used in industry (for instance .stl for 3D parts)

    2. *why* is there such a demand for the machine to ‘replicate itself’?! If you had a cnc mill and a lathe you can (usually) build (or replicate) another mill and lathe. but why bother? The idea seems to be to bring cnc fab techniques to the average user for a reasonable cost. last I checked, even the cheap table top models were going for a few grand. the beta unit on this is going for ~$650.

    3. no competition. looks like someone looked at the other available options and simply said, “I can do better”. so they did.

    Good post.. keep ’em comin..

  3. Damn, I didn’t know about Taig!!

    Check it out, I think you can build your own lathe for around $300 if you don’t mind scrounging a 1/4hp motor and some pulleys. ( $284 for the ‘mill’ chuck and toolset, just need to mount the motor and mill and run the )

    Very cool on this CNC rig though, I hope they can get it done for that price and it is usable.

  4. It’s not like reprap really can replicate itself anyway. Just a few very simple parts. You still need the steel bars, motors, control board, etc.

    That taig mill looks nice, but when are you Americans going to stop dragging your heels and switch to SI units? It’s fair enough to use Imperial for every-day thing, but for engineering?

  5. i agree with medix – the obsession with creating a machine that can replicate itself takes valuable development time away from just creating a cheap, simple machine that does not cost the earth.

    for useful home fabrication we don’t need some crazy von neumann probe; we just need the equivalent of a shitty £20 lexmark printer that can print off simple household items – plates, cups and the little plastic bits that always snap off from tv remote battery lids.

    even if we get to the point that you can manufacture the whole device at home, it will always be cheaper to buy it from a retailer – they will order their materials and processors in huge bulk.

  6. I find all of the talk about self-replication being pointless, or detracting/taking dev time away from reducing costs and improving simplicity quite ironic, as the RepRap is much cheaper than other projects aimed at low-cost high-accessibility (fab@home anyone? Only $3000!). Even the CupCake CNC, which is the cheapest kit printer I’m aware of, owes it’s genesis to the RepRap and its quest for a better, cheaper, faster, replicating printer.

  7. @ Reprap/replication haters

    I think the idea is that you can use the small machine to make parts for a larger machine, and then an even larger machine, until you are at a size that can meet your needs. I believe that is the stated goal of Lumenlab’s DIY CNC machines.


    I agree, didn’t a mars mission crash because of metric to imperial conversion errors at astronomical distances?

    Most especially I am pissed at tools (I mechanic a bit), why should I need a metric toolset and a “standard” toolset?

    Is the Taig only marked in Imperial units?

    Although in real life it probably doesn’t matter which I use, as long as what I build works.

  8. I just had an epiphany(though maybe it’s already obvious to other). Reprap can only replicate a small percentage of it’s parts. Meanwhile things like the circuit boards and the frame of the machine must be purchased separately. It seems the ultimate self replicating fabrication machine would have to combine abilities of milling AND 3d deposition printing.

    The sides for something like the cupcake could be cut out with a milling machine, more complex 3d parts could be made with the 3d printer. Milling would be much more practical than 3d printing for making any of the required circuit boards .

    It wouldn’t necessarily have to be built into the same piece of hardware, but I think that a combination of these two machines would be much better equipped to replicate themselves, by working together. A synergistic combo.

  9. nubie: The markings on the Taig mill are less important than the fact that it uses imperial units on its lead screws (20 threads per inch, giving .05″ per rotation).

    My taig mill is converted to CNC and the controlling software can be set to use either imperial or metric at the click of the mouse, but I’d still need a handful of imperial wrenches even if I chose metric units for all my work.

    back on topic: I wonder what materials the purple crayon is meant to work with. It does not look very rigid, but it is hard to tell.

  10. @nubie: The markings on the Taig mill are less important than the fact that it uses imperial units on its lead screws (20 threads per inch, giving .05″ per rotation).

    My taig mill is converted to CNC and the controlling software can be set to use either imperial or metric at the click of the mouse, but I’d still need a handful of imperial wrenches even if I chose metric units for all my work.

    back on topic: I wonder what materials the purple crayon is meant to work with. It does not look very rigid, but it is hard to tell.

  11. Hey, I can’t claim to be one of the developers (yet, haven’t gotten around to buying the parts to mess with) but I follow the Reprap project (and anything similar I come across) pretty regularly and I wanted to clear up some mistakes/misunderstandings in this thread as well as in the original post.

    * Cupcake == ReRap. The guy selling it is one of the Reprap developers. Reprap is an open source project like Linux. Reprap is to Cupcake as Redhat is to Ubuntu. Sure, there are some differences, but then again there are differences just as large between all the other different prototype Repraps out there as well.

    * Yes, you’ve managed to repeat the same old complaint people have about RepRap, namely, that it can’t replicate itself 100% (or even 50%). Of course, what everyone who makes that complaint fails to notice is that Reprap is a, relatively, young open source project and that OSS projects are notorious for taking a long time to build up steam. Full replication is a long-term goal of the project that even the developers seem to acknowledge will take a long time to even come close to. Consequently, most of the times I’ve seen the self-replication part played up it has been in news stories where the writer is embellishing the point to make the story “extra sexy”.

    * On a, some what, related note to the last point, I believe it was even posted on this site that one of the RepRap designers had managed to successfully demonstrate the production of PCB boards. Also, a number of the developers seem to be experimenting with attaching milling heads to their units.

  12. and to the people wondering about the taig mill increments, yeah, from what I can find, they’re all in english units. However, every mill and lathe I have ever worked on (I’m from the US) has english units on all of the hand-cranks. Most of them now have at least the option to put a reference probe on there, allowing a display to output x, y, and z coordinates in either english or metric units. Personally, I love the metric system, but especially for engineering in America, it’s a hard process to change, since all the old guys used english units, and therefore when they transfer their skills to the next generation, they learn english units, etc, etc. It really kind of sucks, but at the same time, if you’re building something, it can be designed either way without much grumbling. For any sort of calculations, I always just convert to metric first, then convert back when I’m done, since physics calculations are much nicer with metric. Yes, technically you can lose a bit of accuracy, but there’s no way you’re going to lose anything above a hundred thousandth of an inch, so I don’t see it as that much of a big deal.

  13. While there is a bitchfest going let me add a question: Why don’t the vices they use for drillpresses, and CNC variants of that, close equally from both sides instead of having one locked side and one moving side of the clamp? Seems weird to me to have to constantly adjust things because it lack of natural centering.
    I know it’s slightly more complex but when you see the price they ask for something which is basically 2 bars or metal and a screw in its current popular form..
    And yeah you can find selfcentering ones online but they are rare though, very rare.
    Here’s an example: http://www.mukeshtrading.com/work_holding_equipments16.htm

  14. One more note to americans:
    In the EU (mainland I mean, not just britain) they do actually use imperial for various things, like threads on plumbing (taps) for instance, that’s all imperial.
    However if you need a bolt in imperial, like you sometimes do when repairing something, you are in deep shit since they are damn hard to come by in normal hardware stores.
    And yet measuring rulers and such do often come in dual standards with markings in inch and centimeter.
    In short, it’s not so well laid out in metric areas either.

  15. @wwhat : I guess it depends on the country, too. In France you won’t find anything based on imperial units, including plumbing threads you mentioned. France basically invented the metric system during their revolution when they got rid of everything from the past including month and day names, religion, etc …, so it might be more implanted here than in any other country.

  16. not so fast, vic: all common pipe thread standards were developed with imperial units [at least all pipe threads in machinery’s handbook]. check french pipe and you’ll find a whole number of threads per inch.

    also france deserves beaucoup credit for its promotion, but the metric system invention is credited to englishman John Wilkins and it is thought to have arrived in france via americans! [http://en.wikipedia.org/wiki/Metric_system]

  17. The posting about imperial units being base two, versus metric being base 10 should set the intelligent mind to thinking. Computers are now pushing more and more people into thinking in terms of base two. Like most people, I have to flip between metric and imperial. I would love to burn at the stake the person that decided we needed metric and thus created a lifelong need to remember 2.54 and convert from millimeters to inches. If the world was going to change…it would have by now. Imperial has many advantages in engineering work, and I think it more likely the world will convert back to all imperial, rather than embrace metric. Want to try and convince computer programmers that base 10 makes more sense than base 2?

  18. Basing your measurement system on a dead rulers foot is beyond insane. The sooner the world goes metric the better, but some countries like to put it off making it more expensive later.

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