RepRap universal constructor achieves self-replication

The RepRap universal constructor made a successful copy of itself on May 29, 2008.
Adrian (left) and Vik (right) with a parent RepRap machine, made on a conventional rapid prototyper, and the first complete working child RepRap machine, made by the RepRap on the left. The child machine made its first successful grandchild part at 14:00 hours UTC on 29 May 2008 at Bath University in the UK, a few minutes after it was assembled.
Link (Thanks, Michael Nielsen!)


  1. This date would later be regarded as the end of the era of man. When combined with the subsequent artificial intelligence breakthrough of Dr. Osaka in 2014, the development of self-replicating machinery signified the beginnings of the modern robocratic age.

  2. S t’s bl t rcrt ll f th mtl rds nd mtrs, r jst th lttl plstc jnts tht hld t tgthr? Th pg dsn’t sm t b vry clr n ths pnt.

  3. I’m hugely interested in self replicating machinery, metalworking, and other forms of constructing items (I launched SmartFlix based on these interests).

    …and I’ve done a fair bit of reading on RepRap (I was considering building one a year or so back).

    I am dramatically underwhelmed.

    The construction is shoddy, the technique (basically hot-glue extrusion of thermoplastics) is hackish and has poor tolerances, the concept of “self replication” is grossly dumbed down (a very very large number of parts are not constructed, even from high quality inputs, but just store bought), etc., etc.

    In short, I was fairly embarrassed for the RepRap folks.

    Their toy is somewhat cool (although nowhere near as cool as, say, the Gingery lathe that is cast from aluminum melted in a cast iron cookpot, and machines itself as construction progresses), but to claim that it represents any important step forward in self replication …

  4. #5, umbilicaleyeball: Just the plastic doohickeys.

    OK, that’s just freaky. I copied & pasted your user id… the original is all caps, the pasted version is all lower case.

  5. Does this mean that we will be up to our eyeballs in reprap machines in time for the holidays?

  6. This is not “self replication” by any means. Self replication is when I can pour rocks, “replicator ore” if you will, into a big hopper on one side, little smoke stacks bulge and puff rhythmically to the tune of Raymond Scott’s “Powerhouse,” until a bell dings and out on the other side another replicator appears. All they’ve done is made crappy plastic parts. The vast majority of the machine is bought from traditional suppliers. Hell, the thing is made of metal rods for crying out loud.

    Make it out of legos, then we’ll talk.

  7. #7 {txt-trnsfrm: pprcs;}

    Prhps ths wll fnlly hlp m rlz my drm f mkng cntrft Wrhmmr mntrs!

  8. i may be biased as i’ve been involved with the project for a while now, but keep in mind that this is only the very first iteration of this technology!

    of course its not going to be perfect, but neither were the first computers, or the first printers. look how far we’ve come today from the computers of the 60’s, 70’s, and 80’s!

    what we have proven is that the concept of a machine that can make a copy of its parts (even if it is a limited subset of those parts)

    from here on out, its all about refinement and improving the technology.

    try to think outside the box…

  9. It definitely looks like something kludged together, but it works (kind of like the duct tape and spit form of construction, ugly but it works). The fact it can ‘self replicate’ which is kind of a misnomer, it can make the parts which then have to be put together by a person or so it seemed from what I have read and gleaned on comments on it from a few different places. But still this is a VERY important step. We are on our way to seeing this be in more than just a lab now… and as they mentioned the cost wasn’t that high to make another one… wonder just out of materials used in the fabbing process how much it cost to recreate… I wonder if it was cheaper or more expensive than the original ancestor the non fabbed one.

  10. Personally, I think the RepRap folks should drop the Self-Replication talk. It doesn’t. It’s not even close. It’s not even a significant milestone toward that. Everyone hearing that thinks “Wow! Really?”, and when they find out the answer is “No, not really.” they conclude the RepRap is lame.

    They ought to focus on what the RepRap really is: It’s a fabrication machine capable of making various cool stuff, including all the parts of itself you can’t buy off the shelf. That’s not as cool as full self replication, but it’s still pretty cool, and it’s true.

  11. #14 twoshort: Thanks, for saying what I wanted to, but better (and first).

    It’s a great first step, but they’re intentionally misleading people into thinking it’s more than that. RepRap are doing themselves a great disservice by making sure that everybody who learns the truth is disappointed.

  12. Key phrase “Low Cost”.
    This is cool because it reduces the cost, not because it tolls the end of life as we know it.

    Just as OLPC, this product/process lets people who would not otherwise have access to this type of machine have such a thing. Next step is a timelapse video of the process.

    Reminds me of Kiosk, by Bruce Sterling. Thats the kind of temperament that sheds light on this stuff.
    And what’s with FSF taking down the free story???
    It’s not like the internet forgets something. Duh.

  13. …As much as I’ve wanted a 3D printer, the cost of the consumables has scared me away far more than the cost of the printer. But still, this is a great first step. The only thing that could make it better is if the device used simple beach sand!

  14. Reminds me of a favorite story:

    The Mechanical Mice
    by Maurice A. Hugi

    I read it the first time as a youth in a story collection from my school library. Very cool.

  15. OM:

    I think that you will like Reprap Darwin if the cost of consumables bothers you. Whereas commercial plastic filament for printing costs about $4-4.50/cubic inch, Darwin eats standard ABS plastic welding rod costing from $6-8/lb depending on where you buy it. Darwin also uses more exotic plastics like PCL and PLA which are “green” and considerably more expensive but standard ABS does a very good job.

  16. God I hate the negativity. It doesn’t seem to matter what it is whenever something cool is posted we get these wankers who come in and shit on it. Just go away and please keep your cynicism to yourself.

  17. umbilicaleyeball:

    “So it’s able to recreate all of the metal rods and motors, or just the little plastic joints that hold it together?”

    Darwin, which is a first generation Reprap machine, prints the connectors and mounting blocks. That’s about 3 lbs out of a total system weight of 13-15 lbs.

    The project has several lines of development aimed at printing the circuit boards and making the print filament out of recycled plastic. At least one community member is working at making a printable pick and place machine. I, myself, am looking at how to form stepper motor parts and lead screws using electrical discharge machining (EDM). For the purists, no, Darwin only prints about 20% of itself at the moment. We’re working to increase that percentage.

    It’s worth noting, however, that the three lbs of connectors and mounting blocks would cost you something like $2,400 if you had them printed at an agency with a commercial 3D prototyping machine. We’ve gone after the expensive parts first and will be printing the less expensive ones as well as the printers get better.

  18. First off reprap isn’t intended to achieve total replication(yet), just replication of the parts not cheaply available everywhere, like nuts, bolts, and threaded rod. Of course reprap can’t build itself, but reprap might be able to build print out parts to build an assembler capable of assembling repraps from printed parts. See this for more it explains a lot:

    @#4 “Can they do anything other than replicate?”
    Yes, it can print out plastic parts like shoes, door handles, ipod holders, and possibly even GENERATORS and other stuff. (design for a generator that reprap could produce:,11789 )

    People are also working on getting reprap to play a game of chess(scroll down):,12321

    The reason 3d printing consumables cost so much today is because not many people own 3d printers, so companies make their cartridges expensive and hard to duplicate. The Stratasys 3d printers, which have similar resolution and uses the same material as reprap, have a memory chip which tells the printer that it is from stratasys and not just a roll of plastic filament from an alternate vendor.

    Speaking of beach sand, some German CNC machine have parts made from a mixture of sand, gelatin, and a special beer.(second post:,9376,page=1 )

    #10 a replicator made out of legos already exists:
    It only assembled pre-made parts though…
    Here’s some more lego replicators:

  19. I’ll call it “self replication” when it can make ALL the parts AND assemble them. (the next step is the ability to gather raw materials and provide power for itself)

    Until then it still just low cost fabrication of required parts that can’t be purchased.

  20. and I’LL call it “self-replication” when it can say “AND IN THE BEGINNING….”

    C’mon guys, give us a break here. Appreciate the gadget for its obvious merits and suggest improvements. I PROMISE, I absolutely SWEAR that no one here will say you are un-cool.

  21. Dillenger69:

    You can sour grapes and parse definitions till the Sun goes cold and it won’t make a hill of beans worth of difference. The Reprap project will be doing to the manufacturing industry what ink jet printers and word processors did to jobbing printing companies and the copy machine industries or the internet did to the conventional “push” media companies like TV, newspapers and entertainment companies.

    I’ll give you a very powerful example. I own a Jeep. Under the hood it has a plastic tank with a pop-on lid that holds additional anti-freeze for the radiator. That pop-on lid split down the middle on me a few days ago and I am going to have to go to the Jeep dealership and buy another one. The long, long supply chain from the little company that injection moulds that pop-on lid for the Jeep people and which ends up with that lid in a little carton for me which costs about $5-6 because of the inefficiencies of supplying such a part I can print out on a Reprap Darwin printer out of ABS or HDPE in about 5-10 minutes out of plastic that might cost $0.01-0.02.

    On top of paying $5-6 for that silly little lid it will cost me $5-10 in gasoline to drive over to the dealership. We’re talking about the delivered price for that pop-on lid dropping more than 99%.

    Ever had some clown crunch the red translucent cover to one of your rear turnsignals? Try buying one of those at your automotive dealership. We’re not talking $5-10 for something like that. We’re talking a lot more, especially if you have a vintage automobile.

    Reprap Darwin can print you one in a few hours for maybe $1-1.50 in plastic.

    Printing filament, I expect, you’ll be able to buy by the hundredweight at Costco or Walmart in a few years for maybe 10% more than the cost of the raw polymer resin.

    We’re looking at a whole new world.

  22. #4 brrmtt
    “Cn thy d nythng thr thn rplct?”

    Ys, thy cn drn th wlfr systm, cnsm llct drgs nd spry-pnt thngs.

    Th ftr lks prtty brght.

  23. So summarising and extending the posts above.

    It is currently:
    * 91% self replicating by cost (£2400 out of £2700)
    * 20% self replicating by weight (3lb out of 15lb)
    * 0.01% self replicating by complexity (plastic blocks made out of plastic, circuits, motors, extruders, frame)
    * 0% self assembling
    * A good step forwards.

    I personally am very disappointed. I’ve been following this project even to the point of downloading and gearing up to look at the code. It seems to be more active than Fab@Home but to see a news article in the morning paper about self-replicating machines when they’re not seems to be blatantly dishonest.

    I was thinking of going to the Science Festival that’s exhibiting the RepRap this weekend but now my only question would be a very negative, ‘What were you thinking to make such a press release’.

    Hopeful for the future but disappointed by the present.

  24. Assuming the tolerances and strength of the materials are ok, it would be possible to prototype the entire frame in small sections with connectors – it’s merely a question of fab time and cost

    Even if the material isn’t strong enough in the current design, a new sturdier design could be implemented. Tolerances are probably harder to deal with, but will improve with time.

    A fairly obvious truth just occurred to me – in order for a machine to replicate itself in entirety (assuming it doesn’t involve any later assembly) the working envelope has to be dynamic, or beyond the limit of the actual machine – meaning it has to be able to move as it creates. Alternatively it could create small parts that it assembles later (make itself in quarters?). Interesting gedankenexperiment.

  25. Everyone that said that the Reprap people are pushing the wrong thing is right in my opinion, it’s not going to be completely self replicating. You’ll always have to get the extruder nozzle (at least) from somewhere else for example. But that still doesn’t stop the reprap from being very cool.

    What they should be pushing is that you can build a 3D printer for $600 where they usually cost ~$15,000. And then use it to build a second printer for like $200.

    I put in an order for the seeder parts yesterday. Yeah sure the reprap’s idea of a shotglass might be rough, but once you have the base darwin machine, you can use that one to make the more refined next-gen machine.

    I can think of a hundred little plastic doodads that I want to make, including a few proof-of-concept prototypes for patents that have been out of reach financially for me until now. If you’re a doubter, go look at the ipod holder/connector dealie for the car that was made using a reprap. How many times have you run into that situation and had no solution? Now you can make one and do it as elegantly as you’re capable of.

    #11 umbilicaleyeball: Unfortunately the reprap cannot produce anything with more than a 45 degree overhang (yet). I think the martini glass that was made is pushing the tolerances. They’re talking about adding a second extruder that’s filler to get around this But in the mean time you an always print out specific limbs/torso/etc. and glue them together.

  26. plaasjaapie – thanks for the context – This is actually pretty darn neat. Keep up the great job!

  27. The name “Reprap” sounds like something Philip K Dick would’ve thought up…

    In fact the whole story smells of Dick!


  28. My first thought on hearing about a self-replicating machine:
    I want one.

    No, two.

    No, four.

    …uhh…wait a minute.


  29. Well, as long as they’re making something. But if they start doing it for recreational plesaure only, it must be banned.

  30. I too, follow the RepRap developments. but I have decided to branch off on a more conventional manufacturing path, although I am shamelessly borrowing stuff from the RepRap project to get mine going I wanted to use more materials than RepRap is capable of at this point so I started the “CubeSpawn” project.
    the initial cube is a small (1/2 meter) 3-axis CNC mill but I’m planning to build several other cubes for vacuum forming small parts, a tool and head changer for the 3 axis mill, a 5 axis mill, a CMM (coordinate measuring machine) and other stuff as well.

    You can see it here,

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