RepRap: Machines building machine parts

The idea is simple: use a rapid prototyping machine to build duplicate machines, driving down the cost, and making rapid prototyping widely available.

Using manufacturing systems to produce more manufacturing systems is a major goal of molecular manufacturing, the advanced form of nanotechnology. But a group at Bath University is working toward that goal today, and they are not even using nanotechnology.

RepRap stands for "Replicating Rapid-Prototyper." Rapid prototyping (RP) machines have been under development for the last decade or so. They work a bit like a 3D version of inkjet printers, squeezing out plastic in three-dimensional shapes under direct computer control. (Other RP technologies use other materials and processes.)

For the most part, RP machines have only been used to make inert objects, because they can handle only one kind of material. The advance that's put RepRap on the map is the ability to include metal--wires--in a plastic product. If wires can be built in by the computer rather than connected by hand, then more complex products become easier to build.

The RepRap plan requires that the motors, bearings, and computer chips be purchased separately, and a person would need to snap the parts together. Their design is far from finished. But there's no obvious reason why a few hundred dollars of motors, chips, and plastic goop couldn't be turned into an RP machine costing many thousands of dollars today--and the new machine, being inexpensive, could be used to build a wide range of consumer goods that today need large factories to produce them economically.

Molecular manufacturing has several important advantages over RepRap or any other large-scale manufacturing system. Scaling laws mean that small machines can be many times more powerful than large machines. And building with atomic precision lets you take advantage of several physics tricks including superlubricity [PDF paper], zero-wear sliding surfaces, and automatic maintenance of precision in manufacturing operations.

Several advantages are shared between RepRap and molecular manufacturing. The RepRap web site says it very well:

The three most important aspects of such a self-copying rapid-prototyping machine are that:

1. The number of them in existence and the wealth they produce can grow exponentially,

2. The machine becomes subject to [development] by artificial selection, and

3. The machine creates wealth with a minimal need for industrial manufacturing.

The word I replaced in their second point was "evolution." This is because molecular manufacturing has become incorrectly associated with runaway evolution and uncontrolled self-replication. Let's be clear: both RepRap and nanofactories will only build duplicates on command, and only according to the blueprints that are supplied.

Even if RepRap succeeds in making the structural and electrical components of an RP machine, it will have lower performance than a molecular manufacturing system simply because droplets of plastic are far larger and less precise than molecules. But RepRap is a good start. If nothing else, a familiar human-scale machine creating useful duplicate machines will help to mitigate the unreasoning resistance to the idea that a nanoscale machine could do the same.

Chris

Comments

[Will Ware]

If successful, this effort will have raised many of the interesting issues that nanotech will raise, but in a minimally dangerous setting. This could be a valuable public-relations training exercise for Foresight, CRN, and other organizations interested in the course of public debate regarding nanotech.

It's very encouraging to see that they want to GPL this stuff. One can imagine an intellectual property nightmare with self-rep manufacturing technology in the hands of the already-wealthy, while its full benefits forever elude the relatively poor. Even if this specific manufacturing technology has inherent limitations, a precedent for public distribution might steer future policy in benign directions.

[Tom Craver]

So - where does the advantages come from? Shipping costs? - you still have to ship the same mass. Raw materials? No - the same or cheaper materials could be used in a factory.

Labor is is a big savings - many people will be willing to put in their own time rather than money.

The real "exponential growth" benefit here is in marketing. This approach has pyramid marketing built in - the only way you'll get a replicated RAP machine is by using that of an acquaintance. So your pal makes you what looks like 80% of a RAP machine - and gives it to you along with a web site where you can buy the rest of the parts. Who could resist biting on that hook?

Not me! And you KNOW I'm going to want to show it off...

[engr fred kalu]

i what know u idea of compressor machines thanks.

[Chris Phoenix, CRN]

Tom, the other advantage is incremental improvement of the design. It's hard to improve a design when you have to pay $20,000 for each mold. But if you can rapid-prototype, then you can fiddle with the design. You can try new ideas a lot faster when it costs $20 instead of $20,000. And when you get a good design, you have no mold costs to pay off. And less engineering cost, because a lot of the engineering will be hobby, because there'll be lower barrier to entry for hobbyists.

Chris

[Chris Phoenix, CRN]

Fred Kalu, you'll have to be more specific.

Chris

[Brett Bellmore]

Not to mention that processes like stereolithography are capable of producing products that you can't make in other ways; I recall seeing at a trade show once, an interlocking gear train made at one go in a stereolithography machine, that had parts which could never have been assembled together, if they hadn't been made already interlocking.

[richard]

Kitmondo is an online marketplace for used plastic machinery and rubber
machinery including blow moulding, recycling, moulding, plastic lines,
extrusion, mixers & blenders, printing & finishing and thermoforming
machinery.

[VINOD A R]

Would you mind sending me more details with pictures on Reprap as i am curious about it- Thanking u, vinod ar

[Chris Phoenix, CRN]

Vinod, Google can find everything I can find.

Chris