RepRap
From Medialab Prado
Contents |
Notes for ViernesOpenLab RepRap presentation.
Rapid Prototyping
Traditional plastic manufacturing involved expensive re-tooling (generation of moulds etc) followed by large volume mass-production. To be cost effective, they must generate large numbers of the same object.
Rapid prototyping machines require little or no re-tooling for a new design. They do not require large production runs to be cost effective. Most of the costs are in the purchase of the initial machine, and the longer per-piece production times.
Bathsheba Grossman creates mathematically inspired sculptures using 3D printing.
Commercial 3D printers cost ~$30,000+.
The RepRap Project
RepRap stands for "REPlicating RAPid prototyper". The project aim is to make a rapid prototyper that can make most of it's own parts. The current design can make about 60% of its own parts. The rest of the parts are (supposed to be) easy to self-manufacture or purchase (eg, circuit boards, bolts, metal rods).
The self-replication is taken quite seriously, and it integral to the widespread goals of the project.
- Since the machine can print copies of itself, you can't make money by selling the machine, keeping it cheap.
- But you can make a duplicate of the machine for just the materials cost (aimed to be ~$400).
- Since it is useful (provides goods) people will help it to replicate.
- Exponential growth will get the technology into the hands of the most people at the lowest cost.
- The design will evolve though artifical selection (design improved by the community).
- Old machines can print parts for new, improved designs.
RepStrapping
There is an obvious chicken-and-egg problem with building a RepRap, but there are a few solutions.
In the early stages of the project, there was more emphasis on building RepStrap devices (RepRap Boot-Strappers), which are non-replicating rapid prototypers, capable of printing RepRap parts.
At the FoAM workshop, we had the RepRap parts printed on a professional 3D printer. At considerable, and not recommendable cost (~2000EUR).
Now there are a few organisations selling kits of RepRap parts [1] [2].
Costs
A "complete mechanical kit" from bitsfrombytes costs 345GBP (some additional parts required such as the extruder kit 48.50GBP and the electronics/arduino)
The RepRap plans are released under a GPL license.
Materials
The current versions do fused deposition modelling with low-melting point thermoplastic. The first versions used Polycaprolactone (AKA. CAPA / Shapelock / Polymorph / Friendly Plastic). This is a biodegradable thermoplastic that melts at just 60 degrees. This material can be a little hard to get hold of in the filament form used by the RepRap.
Newer versions aim to print using polylactic acid (PLA). It is also biodegradable, and additionally can theoretically be produced by fermenting starch.
Assembly
It still requires human assembly, so it's not likely to take over the world just yet.
The RepRap uses mostly metric sizes for parts, making it easier to build for Europeans.
The current version of the electronics for RepRap uses Arduino. The next generation of electronics will use their own Arduino-like board, which is more powerful.
Goals
The long term goals of the project:
- Low costs bring manufacturing to the worlds poorest people.
- Sourcing materials from biomass and recycling reduce the impact of this manufacturing.
- Local production means fewer factories, less energy spent of transporting goods.
- Possibly less need for money.
"Money is a sign of poverty" (Iain M Banks)
Videos
The reprap in action printing one of its own parts
Adrian Bowyer on the economics of the RepRap
Fab@Home
Fab@Home is not worrying about the self-replicating bit. They are going for ease of construction/use. You get a working printer quicker, that can do more, but it costs more (a full kit costs $3125[3]). The Fab@Home plans are released under a BSD license.
The Fab@Home uses a syringe style printing head that can work with many different materials. Mostly they are materials that are liquid at room temperature and will either dry, or can be baked solid.
The Fab@Home uses mostly imperial sizes for screws and other parts, making some of the parts difficult to source in Europe.
Fab@Home vs RepRap
Other Related Projects
the delicious CandyFab project
More Links
pictures from foam reprap workshop
Resources /supplies
images
this is a picture of a reprap printed part sent to me by the bitsfrombytes people
another one, with a different material (as yet unidentified)..
