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.

You can see it here,
http://www.cubespawn.com

“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.

…and I, for one, etc etc

…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 …

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

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.

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.

Can they do anything other than replicate?

They can also make a really ugly mug.

@#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: http://forums.reprap.org/read.php?1,11789 )

People are also working on getting reprap to play a game of chess(scroll down): http://forums.reprap.org/read.php?1,12321

OM:
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: http://forums.reprap.org/read.php?1,9376,page=1 )

#10 a replicator made out of legos already exists:
http://www.molecularassembler.com/KSRM/3.23.4.htm
It only assembled pre-made parts though…
Here’s some more lego replicators:
http://www.instructables.com/id/3D-chocolate-printer-made-from-LEGO/
http://www.instructables.com/id/Build-a-Polar-3-D-Printer-from-Legos/

No, two.

No, four.

…uhh…wait a minute.

–Devin

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

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

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

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…

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.

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.

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.

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

Th ftr lks prtty brght.

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.