1. Types of 3D printers (SLA, FDM, SLS and Z-printers)
The first 3d Printer, built in 1983 by Chuck Hull was using SLA technology to print with a photoplymer.
Layer by layer, a liquid polymer is exposed to light from a low-power laser and hardens locally. It produces very accurate prints, theoretically capable of tolerances within 100 nm (0.0001 mm), smaller than visible light wavelength, because of the capacity of lasers to focus beams of only a few photons in diameter.
Traditionally a very expensive technology using expensive polymers, recently it became affordable through the Formlab Form 1:
Fused deposition modeling (FDM)
A very popular technology developed in the 80s by Scott Crump and widely available today after the expiration of patents when the large Rep-Rap open-source community started to develop affordable machines using this technology.
The material is supplied as a roll of filament (generally ABS or PLA), a hot nozzle melts it, extrudes it and deposes it in layers to build up a 3d model.
Selective laser sintering (SLS) and other variations (DMLS, SHS, SLM, EBM)
Developed in the mid 80s by Carl Deckard in Austin, Texas. Similar to SLA, SLS machines use a more powerful laser to fuse together powdered particles of a variety of materials (plastic, metal, glass, porcelain etc). The advantage of this technology over SLA and FDM is that prints do not require support structures, because of the ability of the powder to support cantilevering layers above.
Plaster-bed printing (PP)
Z-printers were developed in 1995 at MIT use layers of plasters and an ink-jet print-head that uses a binding resin to harden the plaster powder. Because of the possibility of using different colours of resin, the Z-corps are capable of building full-colour models. They are also capable of printing cantilevering structures without support. Plaster 3d prints have a very good resolution but are soft and fragile and need to be glued.
2. Replicating Rapid-prototyper (Rep-Rap)
A Rep-rap is a machine that can be built using only standard off-the-shelf parts (nuts, bolts, stepper motors etc) and parts that it can 3d-print itself (generally joints and connection pieces).
Adrian Bowyer developed the first prototype in 2004 at the University of Bath. Since then, the project grew exponentially, currently having hundreds of family members, versions, updates and spin-offs. The original Darwin used FDM technology and a cartesian movement system, the nozzle moving in the two horizontal axes XY while the print bed moves vertically in Z direction.
To day most rep-raps are FDM machines based on cartesian coordinate systems, the two most advanced branches in the family being the Prusa Mendel (XZ Head; Y Bed), the PrintrBot/Up! (X Head YZ Bed); the MakerBot (Z Head; YZ Bed) and the Ultimaker (XY Head; Z Bed).
Other technologies have been adapted to be used in Rep-Raps, such as the CandyFab, a selective sintering machine that uses a heat source and sugar as raw material:
A reprap SLA machine is also available as a kit for about 600$ from Veloso, only one available as far as I am aware.
Newest trends are in developing rep-rap printers that are non-cartesian and based on different coordinate systems. Check out these cool machines:
A SCARA coordinate system machine:
A POLAR coordinate system machine:
A DELTA coordinate system machine:
Amazing projects are always kickstarted, check this one out for a printer under $100:
3.Be the first to 3d print a house!
Currently in the world there are three working large scale 3d printers aimed at manufacturing buildings:
1. The Italian based D-Shape by Enrico Dini:
And a prototype for Foster’s Moon Base also done with the D-Shape:
3. And the Contour Crafting by Behrokh Khoshnevis from the University of Southern California: