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GNU is Not Unix Patents Hardware

3D Self-Replicating Printer to be Released Under GNU License 313

Rob O'Neill writes "A Kiwi open source developer is working on a self-replicating 3D printer, RepRap, to be made available under the GNU license. 'The 3D printer works by building components up in layers of plastic, mainly polylactic acid (PLA), which is a bio-degradable polymer made from lactic acid. The technology already exists, but commercial machines are very expensive. They also can't copy themselves, and they can't be manipulated by users, says Vik Olliver. RepRap has a different idea. The team, which is spread over New Zealand, the UK and the US, develops and gives away the designs for its much cheaper machine, which also has self-copying capabilities. It wants to make the machine available to anybody — including small communities in the developing world, as well as people in the developed world, says Olliver. Accordingly, the RepRap machine is distributed, at no cost, under the GNU (General Public License).'"
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3D Self-Replicating Printer to be Released Under GNU License

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  • Really? (Score:5, Insightful)

    by Anonymous Coward on Monday April 07, 2008 @05:29PM (#22994292)
    How does it copy its circuit boards and metallic components? Does it have a little semi-conductor factory?
    • Re:Really? (Score:4, Informative)

      by Otter ( 3800 ) on Monday April 07, 2008 @05:42PM (#22994420) Journal
      Apparently "RepRap also allows people to build circuits in 3D". I don't think the article is claiming that it *can* copy itself, though (if it could, they'd have more than seven in existence), just that that's their eventual goal.
    • We know that people are going to use the printer to try to make weapons [and] sex toys and drug paraphernalia,

      And your concerned about circuit boards?
      Seriously, that's a good point though, the article isn't really clear.

      A head that deposits low melting-point metal is in development, he says.

      Yet the article also states:

      RepRap also allows people to build circuits in 3D

      Just what are these circuits made of? Or are they just masks you can lay down on a PCBA, leaving you to solder it all together? Anyone know?

    • Re:Really? (Score:5, Interesting)

      by vrmlguy ( 120854 ) <samwyse@COUGARgmail.com minus cat> on Monday April 07, 2008 @05:46PM (#22994460) Homepage Journal

      New features include, for example, heads that can be changed for different kinds of plastic. A head that deposits low melting-point metal is in development, he says. The metal melts at a lower temperature than that at which plastic melts, which means the metal can be put inside plastic, says Olliver. "That means, in theory, we could build structures like motors."
      Of course, the main part of a motor usually consists of really long wires wrapped into coils. I'm not sure how well a non-wrapped version would work, but yes, in theory it's possible. More feasible would be building a jig to help me wind my own motor coils.

      Also, it sounds like it would be trivial to build a PC "board". It wouldn't have to be flat, and you wouldn't need to etch it. You could have places on your device to surface attach ICs.

      • Re: (Score:2, Interesting)

        by Tangent128 ( 1112197 )
        You can still make wrapped coils, methinks. Just build them up in cross-sections. The printing resolution would likely limit how tight you could get it, though.
      • Re:Really? (Score:4, Interesting)

        by flappinbooger ( 574405 ) on Monday April 07, 2008 @08:59PM (#22995916) Homepage
        This kind of thing is coming, and it WILL revolutionize the world.

        Rapid prototyping and even direct-to-manufacture with the selective sintering machines is becoming much more accessible and widespread.

        Think of it as mimeograph and dot matrix from 20 years ago vs the mundane throwaway photo-quality walmart variety printers now.

        "Hang on, mama, I need to print out a new carburetor before we can go to the tractor pull!"
        • Re:Really? (Score:5, Insightful)

          by fireboy1919 ( 257783 ) <rustyp@@@freeshell...org> on Tuesday April 08, 2008 @02:25AM (#22997544) Homepage Journal
          Rapid prototyping and even direct-to-manufacture with the selective sintering machines is becoming much more accessible and widespread.

          Think of it as mimeograph and dot matrix from 20 years ago vs the mundane throwaway photo-quality walmart variety printers now.


          While I agree, I don't think that this particular technology is where it's at.

          You should keep in mind that this is essentially a computer controlled glue gun. It requires the use of low-temperature, air pressure thermoplastic, or similar materials.

          Those kinds of materials just don't stand up to abuse. You need to be doing this kind of thing at high temperatures and pressures to make it practical, and then it starts to get dangerous. Further, building layer upon layer in this printing fashion does not lend itself to strong bonds within the material.

          What can we do at low temperatures that can do this kind of thing? Rather than adding material to objects, the trick is to remove it.

          We have computer controlled routers, lathes, and milling machines that can cut through pretty much any kind of metal or wood with accuracy that far surpasses that of the RepRap, and the end result is sturdier.

          Its not like the "waste" is even that, either - metal scraps can be melted down and reused, and wood scraps can be made into compost, kindling, paper, or particle board.

          A machine that does this is called a CNC machine, and they already exist. You can buy one ready made, or find tons of articles on the internet discussing how to make one - mostly out of parts available at hardware stores, so they end up being between easily available in the $400-$1500 range.
          • Re: (Score:3, Insightful)

            I've heard about CNC milling machines. I've had many of the parts I've designed made on them.

            For building a piece of capital equipment, the parts must be designed in CAD and the DXF files and part prints must be created. Then all of the sheet metal parts, steel plate parts, machined parts, purchased parts, and hardware have to all be ordered, made, purchased, borrowed, etc.

            What if, some day, a company that wanted to design and build a piece of capital equipment could do so - all internally? Without
    • Re:Really? (Score:5, Informative)

      by PinkFuzzyBunny ( 998076 ) on Monday April 07, 2008 @06:14PM (#22994728)
      Currently the machine can produce %60 (by mass) of it's non-electronic components with the remainder being largely commonly available (metric) hardware like rods and bolts. Work is underway on a printhead capable of printing circuit traces via solder type alloys. Actual printing of semiconductor devices is still in the early research and implementation phase at various corporations and universities. Printable motors are the remaining practical hurdle. So granted this is a 0.1 version. It still however represents an order of magnitude drop in the price of 3d printing devices, and thus seems worth some attention.
      Also as to the applicability of the GPL to a device, It is the plans, designs, and instructions which are GPL'ed and, Yes copyright has been used in attempts to control physical device distribution(Epson printer cartridges I believe).
      • A different, but similar project has already been discussed on slashdot here: http://hardware.slashdot.org/article.pl?sid=07/01/09/2239206/ [slashdot.org]

        It also needs some commodity parts for full replication. This is also still in active development, and I'm glad to see multiple groups working on this concept.
      • Re:Really? (Score:5, Funny)

        by inkyblue2 ( 1117473 ) on Monday April 07, 2008 @07:38PM (#22995374)

        Actual printing of semiconductor devices is still in the early research and implementation phase at various corporations and universities. Printable motors are the remaining practical hurdle.
        lol. i'm almost done building a space shuttle out of papier mache. the only parts i'm still working on are the engines and the heat shielding for re-entry. consider this a 0.1 version.
    • Re:Really? (Score:4, Funny)

      by joaommp ( 685612 ) on Monday April 07, 2008 @06:19PM (#22994782) Homepage Journal
      They can replicate all they want, we will still find a way to disrupt them. If we get in real trouble and they go after the asgard core, we call our ancient next door.
    • Re: (Score:3, Interesting)

      by shrikel ( 535309 )
      A lot of the wording on the site refers to an idealized version of the RepRap; i.e. what they hope to have someday. As of right now, they're still working on getting it to fabricate the plastic parts.

      Currently it only builds things out of extruded thermoplastic. But it would certainly be possible (and this is a future plan) to use other materials. From the plastic extrusion they're doing now, it's a relatively small step to add a solder-extruder as well, allowing for circuit boards to be assembled.

      Actu

    • by countach ( 534280 ) on Monday April 07, 2008 @06:30PM (#22994882)
      What happens when these things run out of control replicating themselves, and the planet becomes a crawling oooze of 3D printers? Have they thought of that? No, I'll bet not. Smash any 3D printers you can see NOW!
    • Re:Really? (Score:4, Informative)

      by Plazmid ( 1132467 ) on Monday April 07, 2008 @06:51PM (#22995048)
      Currently, it doesn't. But, there are several ways to produce circuit boards: The most promising is milling copper clad with a router attachment instead of a 3d printhead(called an extruder). Other ideas include printing a sheet of plastic with trenches in it and filling up the trenches with low melting point alloy to connect the components. There's also conductive ink, but that's a wee bit expensive.(made from silver) Reprap can't do metal parts yet, but there are several ideas on doing this, either print out the metal directly with a special metal printhead, or print a wax part, and do lost wax casting. As for semiconductors, it might be a while before someone does that. If you're worried about RepRap taking over the world, you still have some time, the prototype printer has only printed 99% of its printable parts.
    • I for one welcome our inkjet overlords.

      In Soviet Russia printer prints printer!

      Sheesh, this story has been up for minutes now, keep up, I don't want to have to do everything around here...
  • Real headline (Score:2, Informative)

    by nog_lorp ( 896553 ) *
    The real news here is, "RepRap has reached it's goal of being self-replicating". I'd heard they were striving for that, but this is a cool achievement.
  • Text (Score:5, Informative)

    by blhack ( 921171 ) on Monday April 07, 2008 @05:31PM (#22994322)
    I think they're web server was built out of plastic parts made by a reprap...its already failing hard. Here is the text from the article:

    Based in the Waitakeres, in West Auckland, software developer and artist Vik Olliver is part of a team developing an open-source, self-copying 3D printer. The RepRap (Replicating Rapid-prototyper) printer can replicate and update itself. It can print its own parts, including updates, says Olliver, who is one of the core members of the RepRap team.

    The 3D printer works by building components up in layers of plastic, mainly polylactic acid (PLA), which is a bio-degradable polymer made from lactic acid. The technology already exists, but commercial machines are very expensive. They also can't copy themselves, and they can't be manipulated by users, says Olliver.

    RepRap has a different idea. The team, which is spread over New Zealand, the UK and the US, develops and gives away the designs for its much cheaper machine, which also has self-copying capabilities. It wants to make the machine available to anybody -- including small communities in the developing world, as well as people in the developed world, says Olliver.

    Accordingly, the RepRap machine is distributed, at no cost, under the GNU (General Public Licence).

    RepRap's open-source project aims to keep on improving the machine. "So it can do what people want it to do", says Olliver. Improvements will go back to users and, in this way, the machine as a whole evolves, he says. The idea of evolution is important, he adds. The device Olliver is creating now will probably bear very little resemblance to the device that will appear on everybody's desks in the future, he says.

    "We want to make sure that everything is open, not just the design and the software you control it with, but the entire tool-chain, from the ground up," he says.

    Olliver works for Catalyst IT, a Wellington-based open-source business system provider. He is fortunate enough to get "Google-time" from the company, which means he is allowed to work on his own research projects one day a week -- just like employees at Google. This has led to considerable developments in the RepRap project in the last six months, his says.

    New features include, for example, heads that can be changed for different kinds of plastic. A head that deposits low melting-point metal is in development, he says. The metal melts at a lower temperature than that at which plastic melts, which means the metal can be put inside plastic, says Olliver. "That means, in theory, we could build structures like motors."

    RepRap also allows people to build circuits in 3D, as well as various shapes, with the result that objects, such as a cell phone, don't have to be flat, he says.

    There are at least seven copies of the RepRap machine in the world that Olliver knows about. The 3D printer also allows for a new and fascinating way of communicating: Olliver can design something at home in New Zealand, which then appears on another researcher's desk, in Bath, in the UK, or the other way around.

    At the moment, the RepRap uses two different kinds of plastic -- PLA, a relatively rigid plastic, which is ideal for making objects such as corner brackets; and a more flexible plastic for making, for example, iPod cases, he says.

    But having the machine copy itself is the most useful thing the team can make it do, and that is the primary goal of the project, says Olliver. However, it can also be used to make other things, such as wine glasses -- definitely water-tight, he adds -- and plastic parts for machines. When Computerworld talked to him, Olliver had just printed out a small part to fix his blender.

    "We know that people are going to use the printer to try to make weapons [and] sex toys and drug paraphernalia," he says. "This is obviously not what we're hoping they are going to build. We are hoping they are going to build more and better RepRaps."
  • Skynet Tag (Score:3, Funny)

    by kylehase ( 982334 ) on Monday April 07, 2008 @05:31PM (#22994324)
    Self replicating machines... need a Skynet [wikipedia.org] tag.
  • GNU license? (Score:5, Interesting)

    by sharkb8 ( 723587 ) on Monday April 07, 2008 @05:35PM (#22994336)
    It's too bad that the GNU license doesn't cover a machine. It's for copyright. Copyright would cover the RepRap diagrams and schematics, however, the functional elements of the RepRap aren't covered by copyright. I suppose they could have patented aspects of RepRap, and licensed the patents under the GNU license, but I haven't seen anything like that. Anyone seen any patents or patent applications on this? (Zach over at NYC Resistor has a working model, it something to see in person)
    • Re:GNU license? (Score:4, Informative)

      by QuantumG ( 50515 ) * <qg@biodome.org> on Monday April 07, 2008 @05:40PM (#22994390) Homepage Journal

      Copyright would cover the RepRap diagrams and schematics
      And that's exactly what they've put under the GNU license.

      • Re:GNU license? (Score:4, Interesting)

        by sharkb8 ( 723587 ) on Monday April 07, 2008 @05:53PM (#22994542)
        Any machines you make from the schematics are not covered under the GPL, only the schematics. As long as you use the schematics according go the GPL, you don't have to release any changes to the machine itself back into the public domain. Thus, as long as you're not modifying the schematics themselves, releasing them under the GPL is almost useless. And there's a lot of questions regarding the copyright protection afforded schematics as most of what schematics describe is functional ,and not artistically creative.
        • by QuantumG ( 50515 ) *
          The point is simply that the schematics are freely available.

          The GPL is more a social contract than a legal one.. if someone releases something under the GPL, only a rude person will hoard their changes.

  • by pete-classic ( 75983 ) <hutnick@gmail.com> on Monday April 07, 2008 @05:37PM (#22994360) Homepage Journal
    Can this printer print a printer so large it, in fact, can't print it?

    -Peter
  • by TheNarrator ( 200498 ) on Monday April 07, 2008 @05:45PM (#22994454)

    There are at least seven copies of the RepRap machine in the world that Olliver knows about. The 3D printer also allows for a new and fascinating way of communicating: Olliver can design something at home in New Zealand, which then appears on another researcherâ(TM)s desk, in Bath, in the UK, or the other way around.


    So I'm going to double click an email attachment and wake up the next morning to find my house infested with little insect like robots wandering around my house looking for credit cards.
  • by binarybum ( 468664 ) on Monday April 07, 2008 @05:46PM (#22994458) Homepage

    "We know that people are going to use the printer to try to make weapons [and] sex toys and drug paraphernalia," he says. "This is obviously not what we're hoping they are going to build. We are hoping they are going to build more and better RepRaps." ... so that we can then use those to build more and better weapons [and] sex toys, drug paraphernalia.
    • Re: (Score:2, Insightful)

      by Anonymous Coward
      Weapons and illegal drug paraphernalia I can understand, but what do they have against sex toys?
    • But the humans won't stop there. They'll make bigger boards and bigger nails, and soon, they will make a board with a nail so big, it will destroy them all! Kang
    • by ceoyoyo ( 59147 )
      "weapons [and] sex toys and drug paraphernalia"

      Do weapons and sex toys have some kind of association that requires the use of an "and" as opposed to a comma?
  • I'm sure it's "Ink" (media) is something like a wax or a plastic.

    I can't get to the article right now but I wonder how hard it would be to have the printer make a machine to create its own "ink" from common household items like sand/glass oil and animal fat, something bizarre like that.

  • by lobiusmoop ( 305328 ) on Monday April 07, 2008 @05:51PM (#22994518) Homepage
    Since this is (presumably) doing analogue-based copying, I imagine it's inevitable it would suffer from degradation between copies, similar to copies of old-school video/audio tape.

    And would interesting mutations get in, like in DNA replication, I wonder?
    • by shrikel ( 535309 ) <hlagfarj&gmail,com> on Monday April 07, 2008 @06:09PM (#22994680)
      It doesn't "copy" itself, per se. It is a rapid prototyper; a machine capable of taking a digital description of an object and then fabricating that object by itself (in this case, using layers of extruded thermoplastic). So no, degradation is not an issue here.

      I guess you could build some sort of scanner-type machine that would scan an object and create a digital description of it. Then maybe you could get generation-based degradation, if you really want to. ;)

      • by Qzukk ( 229616 )
        Then maybe you could get generation-based degradation

        I think the idea is that maybe the measurement will be slightly off in the first generation, leading to the track the head runs on to be slightly wider in the second generation, leading to a machine that stretches everything it produces by 0.05% in one dimension in the third generation, which just happens to have been assembled so that the nozzle points along the other axis and produces things stretched by 0.05% in one dimension while 0.05% thicker in the
  • When will we see a server, which replicates itself, to handle a slashdotting?
  • Official links (Score:5, Informative)

    by FleaPlus ( 6935 ) on Monday April 07, 2008 @05:53PM (#22994540) Journal
    Particularly since the news article seems to be down, here's the official site, which has some neat photos of RepRap:

    http://reprap.org/bin/view/Main/WebHome [reprap.org]

    Here's their main blog, where you can keep track of progress on RepRap:

    http://blog.reprap.org/ [reprap.org]
  • by PRMan ( 959735 ) on Monday April 07, 2008 @05:54PM (#22994546)

    But the liquid plastic cartridges are $250 each...

  • Here's the real site. [reprap.org] Look at the picture. The machine can make the white plastic parts. Not the motors, not the leadscrews, not the frame rods, not the belts, not the wiring, and not the control electronics. The parts it is making look like about $10 worth of injection molded plastic - the cheap parts.

    • by OrangeTide ( 124937 ) on Monday April 07, 2008 @06:06PM (#22994666) Homepage Journal
      Small orders of custom injected molded plastic never cost only $10.

      And $650 $45000.
    • by Grishnakh ( 216268 ) on Monday April 07, 2008 @06:17PM (#22994756)
      Here's the real site. Look at the picture. The machine can make the white plastic parts. Not the motors, not the leadscrews, not the frame rods, not the belts, not the wiring, and not the control electronics. The parts it is making look like about $10 worth of injection molded plastic - the cheap parts.

      Wrong; that's not $10 worth of injected-molded plastic, that's thousands of dollars worth at least.

      Injection-molded plastic, as the name implies, requires a mold, and a machine to inject plastic with. Molds are expensive, as are these machines. Do you have the facilities at home to make injection-molded plastic parts? No? Then it's going to cost you a fair bit of money to send your CAD drawings to a place for them to make a mold and produce parts for you in large quantities. You say you only need one? Too bad. The cost isn't much different whether you want one or 1000.

      That "$10 worth" of parts is only $10 when someone has gone to the trouble of making molds and doing a production run in the thousands or more.

      With a machine like this, those parts can be made for next to nothing. You'll still have to add motors, leadscrews, belts, wiring, etc., but all that stuff is easily bought off-the-shelf, since it's all standardized. Special plastic parts for your particular application aren't available off-the-shelf, and that's the problem solved here.
  • How soon will it be before we manage to produce Von Neumann probe [wikipedia.org]?

    Hint to the project leader: Contact NASA, this is some cool stuff. Just don't screw up like the Slylandro [wikipedia.org] did.

    --
    Toro
  • by Toonol ( 1057698 ) on Monday April 07, 2008 @06:00PM (#22994604)
    If this can be pulled, off, it could be world-changing. Imagine being able to download plans and create anything out of varieties of plastic! It would be the key to untold riches, with the only limitation the supply of cheap and plentiful... petroleum products.

    Oh, never mind.
    • Re: (Score:3, Insightful)

      Actually several of the plastics in use are produced from plant materials, others are silicone based. Even if the plastics used are petroleum based the thermoplastic nature of the device makes recycling both obvious and decentralized. So yes, maybe a world changer.
    • Re:The singularity (Score:5, Insightful)

      by Grishnakh ( 216268 ) on Monday April 07, 2008 @06:26PM (#22994846)
      Unless I'm missing something, TFA said the typically-used plastic on these printers is PLA, polylactose acid, which is made from lactose, an ingredient in milk, human muscles, and various other biological sources, not petroleum.
  • whoo! lego! (Score:4, Funny)

    by kris.montpetit ( 1265946 ) on Monday April 07, 2008 @06:02PM (#22994626)

    this is going to be the ultimate answer to lego. Which of course means as soon as it comes out, it will destroy the social lives of millions of tinkering adults.

    At least the cat can't pee in it XD

    • by IdeaMan ( 216340 )
      Lego should invest in this heavily. They could get in at the ground floor by offering a Steam-like service where you can buy Lego plans online. You know all those custom parts Lego keeps coming up with? Instead of selling them in kits sell the plans for each piece.

      Instead of it being the death of Lego, it could be the birth of Legos ginormous monopoly on small printed plastic parts.
  • by fiannaFailMan ( 702447 ) on Monday April 07, 2008 @06:18PM (#22994764) Journal
    Tea. Earl Grey. Hot.
  • Missing the forest (Score:5, Interesting)

    by Telvin_3d ( 855514 ) on Monday April 07, 2008 @06:23PM (#22994812)
    I've been following the RepRap project for quite a while now. They have some really interesting ideas and a wonderful vision of the future.

    However, in my opinion (such a rare thing on the internet) they are so enthralled with their grand ideas that it prevents them from actually getting anywhere. From their point of view, any design that can not replicate itself (except the metal) is an inherent failure. The other properties of the machine only start to matter once that is achieved.

    While there is nothing wrong with the goal, it means that there is almost no drive at all to produce a machine that is practical for anything BUT duplicating its own plastic parts. Their design calls for basic, lumpy plastic bits and so there is no emphasis on better precision. They are only willing to use materials that can be made yourself, and so there is no chance of it working with better quality plastics. They have designed a machine that needs no small parts or detail work and so there is no emphasis on getting a print head design or motors that supports a better resolution, not that the current plastic could support a better resolution.

    Five years from now they are going to announce they they have been able to successfully create a machine that can cheaply and easily replicate itself and that now they will work on making it better. And not even /. will cover the announcement because there will be consumer machines on the shelves that don't cost that much more, are more dependable and can do useful work. And it's a real shame.
    • Missing the point (Score:4, Insightful)

      by vik ( 17857 ) on Monday April 07, 2008 @06:56PM (#22995090) Homepage Journal
      The design is meant to evolve. It won't do that until it replicates. Therefore, the most critical thing to do is make it replicate. If we spent our time making cool gadgets with it, this would delay the onset of replication and keep the thing out of your hands. It is only when large numbers of people can get hold of the thing that the design will evolve.

      Besides, making it capable of producing its own parts automatically makes it capable of creating a whole heap of other stuff. People are subverting bits of the design already.

      Vik :v)
    • by grumbel ( 592662 )

      And not even /. will cover the announcement because there will be consumer machines on the shelves that don't cost that much more, are more dependable and can do useful work.

      Such devices are already available, but they cost thousands of dollar, since there is little chance of these to ever become mass marketed I doubt that their price will fall anytime soon or ever for that matter. However what might likely happen is that somebody will allow you to send in your CAD design by email, get it printed out and then send it back to you. There already is a shop that is doing that for World of Warcraft character models, including custom armor, color and stuff, can't take long till some

    • But that's like complaining that the OLPC won't run Vista. That's not it's point, which is to put something otherwise inaccessible into the hands of the masses. By requiring it to work with materials you can make yourself, even the relatively impoverished can start using one without having to scrounge expensive supplies from charities or other benefactors.

      Sure, it's a poor knock-off of industrial grade machines - in almost exactly the same way that an OLPC is a poor knock-off of a mainframe.

  • by RexDevious ( 321791 ) on Monday April 07, 2008 @06:59PM (#22995108) Homepage Journal
    "We know that people are going to use the printer to try to make weapons [and] sex toys and drug paraphernalia," he says.

    All you have to do is, when some tells the machine to print a copy of itself - have it print a weapon instead. Then it points it at the user and says, "Go buy another copy of me and tell everyone I printed it. And if you think you can come back here with the police instead - keep in mind that I can also print sex toys and drug paraphernalia. So... do we understand each other?"

    Granted, it'd make for some pretty awkward moments at trade shows - but it would still technically be a self-replicating printer.
  • How long until I can make a sex android?

    Seriously.

  • Sure, this printer might be able to reproduce itself, but how can we be sure that it will always reproduce a copy of its complete corresponding source code? Or at least a written offer? What happens if it doesn't honour the written offer? Can its ability to propagate itself be revoked?

  • Unfortunately, the ink required to print a new printer costs 200% what a new printer would cost.
  • Kiwi? (Score:4, Funny)

    by fm6 ( 162816 ) on Monday April 07, 2008 @07:32PM (#22995332) Homepage Journal

    A Kiwi open source developer...
    Do you mean the fruit, or the extinct flightless bird? Either way, I find it difficult to take the project seriously!
  • by Animats ( 122034 ) on Monday April 07, 2008 @09:16PM (#22996010) Homepage

    If they actually start making the hard parts, they'll run into some of the tough problems of machine shop work. A classic problem: how to make a leadscrew more precise than the one you've got. If you just make a new one using an existing one for positioning, each generation of copy will be worse than the previous one.

    Maudsley solved this problem between 1800 and 1810, with his "screw-originating machine". This makes a very accurate screw, slowly and in a soft metal. This screw is then used in a thread-cutting lathe to make second generation leadscrews that aren't quite as good. So most screws are "descended" from a reference screw, and are only a few generations removed from it.

    There are other ways to approach the problem today, typically using some form of position feedback separate from the drive mechanism. For a self-replicating machine that doesn't get precision parts from an external source, position measurement via absolute means, like interferometery, as in a ruling engine, might be necessary.

    Right now, the RepRap people are punting on the generation loss problem, because they're only making the easy parts. If they're serious, they'll need to solve it.

  • by ignavus ( 213578 ) on Monday April 07, 2008 @11:29PM (#22996734)
    I tried using one of these fancy 3D printers to print my assignments, but all it did was make my mistakes stick out.

It is wrong always, everywhere and for everyone to believe anything upon insufficient evidence. - W. K. Clifford, British philosopher, circa 1876

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