More On DIY Fabricators
Back in January I made a post which talked about Fab@Home, a collaborative project to develop a cheap, non-proprietary desktop fabricator (or rapid prototyper) which anyone can build. Their latest news is that Koba Industries has begun offering complete kits for their Mark I fabricator.
Last night I stumbled across another group of home fabbers called RepRap. The goal of this project is to produce a fabricator which can create its own parts1, so that once you've built one fabricator you can use it to produce the parts for as many more as you want. It isn't limited to just replicating itself, of course, it will build any shape programmed into it, but replicating its own parts is a neat and useful target to shoot for.
There are a number of differences between the two projects which make them complement each other rather well. Fab@Home's fabber extrudes the fabrication material through a syringe. This allows it to use a wide variety of materials, such as silicone and even peanut butter, but requires that the material be soft enough squeeze out in a thin bead. As a result it is incapable of producing objects any harder than, say, the dried silicone caulking around your bathtub2. RepRap uses a heated nozzle which extrudes melted plastic3. As a result, it can produce quite hard and durable objects but is limited to small range range of specialty plastics which are more expensive than silicone caulking.
These differences reflect the different aims of the two groups: Fab@Home wants to encourage people to experiment with cheap fabrication while RepRap wants to produce usable parts.
RepRap is much cheaper with the total cost of parts and materials coming in at around US$500 as opposed to Fab@Home's US$2,500. However a big part of that cost reduction is due to the fact that RepRap requires a lot more construction effort. For example, you can buy a syringe for a Fab@Home replicator at any drug store but RepRap's heated nozzle requires drilling 0.5mm holes into 3mm wide brass bolts, filing the head down to a conical shape, wrapping it with heater wire, and so forth.
But as one of the sites pointed out, there's nothing to stop you from mounting RepRap's heated nozzle onto Fab@Home's fabber, thus getting the best of both worlds. So I'm watching both of these groups with great interest.
1There are limits to how much of itself RepRap will be able to create. For example it won't be able to create the chips used in its circuitry but will be able to produce the circuit boards.
2[EDIT] As noted in the comments, there are syringe-able materials which will dry to a harder finish than silicone caulking, such as epoxies, gypsum paste and even regular wood glue.
3Actually RepRap isn't limited to plastics. It can use any material whose melting point lies within the range of the heated nozzle (about 250C) and has the right viscosity. This includes a few soft metals. In particular they are now experimenting with extruding solder, an important step in reproducing the machine's circuit boards.
Last night I stumbled across another group of home fabbers called RepRap. The goal of this project is to produce a fabricator which can create its own parts1, so that once you've built one fabricator you can use it to produce the parts for as many more as you want. It isn't limited to just replicating itself, of course, it will build any shape programmed into it, but replicating its own parts is a neat and useful target to shoot for.
There are a number of differences between the two projects which make them complement each other rather well. Fab@Home's fabber extrudes the fabrication material through a syringe. This allows it to use a wide variety of materials, such as silicone and even peanut butter, but requires that the material be soft enough squeeze out in a thin bead. As a result it is incapable of producing objects any harder than, say, the dried silicone caulking around your bathtub2. RepRap uses a heated nozzle which extrudes melted plastic3. As a result, it can produce quite hard and durable objects but is limited to small range range of specialty plastics which are more expensive than silicone caulking.
These differences reflect the different aims of the two groups: Fab@Home wants to encourage people to experiment with cheap fabrication while RepRap wants to produce usable parts.
RepRap is much cheaper with the total cost of parts and materials coming in at around US$500 as opposed to Fab@Home's US$2,500. However a big part of that cost reduction is due to the fact that RepRap requires a lot more construction effort. For example, you can buy a syringe for a Fab@Home replicator at any drug store but RepRap's heated nozzle requires drilling 0.5mm holes into 3mm wide brass bolts, filing the head down to a conical shape, wrapping it with heater wire, and so forth.
But as one of the sites pointed out, there's nothing to stop you from mounting RepRap's heated nozzle onto Fab@Home's fabber, thus getting the best of both worlds. So I'm watching both of these groups with great interest.
1There are limits to how much of itself RepRap will be able to create. For example it won't be able to create the chips used in its circuitry but will be able to produce the circuit boards.
2[EDIT] As noted in the comments, there are syringe-able materials which will dry to a harder finish than silicone caulking, such as epoxies, gypsum paste and even regular wood glue.
3Actually RepRap isn't limited to plastics. It can use any material whose melting point lies within the range of the heated nozzle (about 250C) and has the right viscosity. This includes a few soft metals. In particular they are now experimenting with extruding solder, an important step in reproducing the machine's circuit boards.