Cofa's 3D printers

Cofa's 3D printers are now located in the Fish Bowl, off the courtyard in D block. Three small UP 3d printers have been are now available, capable of printing objects 140x140x135mm in ABS plastic filament. They feature snap off lower density support material, with selectable layer resolutions of 0.15mm , 0.2mm, 0.25mm, 0.3mm, 0.4mm .

The new PRotos X 400 is a German RepRap machine building a precise layer thickness of 0.1mm and a huge print area of 400 x 400 x 350mm,the largest in it's class.The nature of repraps requires a higher degree of operator involvement to developing personalised profiles expected in more expensive 'out of the box' commercial machines, and the PRotos is currently being 'learnt' and calibrated. Like the UP printers, it builds with standard PLA and ABS filament, so is a very cost effective option for 3D printing.




The Dimensions SST 1200 series printer is capable of printing 3D objects in ABS plastic in sizes up to 254 x 254 x 305 mm at a detail resolution of 0.25mm or 0.33 mm . The printer uses an FDM type technology , employing an inkjet printer like mechanism to deposit plastic along a drawn path. The printer builds up may layers of these ‘paths’ to create the three dimensional model. Adjacent to the path, where necessary, the printer also deposits a support material.The SST is getting long in the tooth but still produces reliable, high quality prints.The model is made from ABS, and the support material from corn starch based plastic. Once the model is completed it is placed an alkaline bath which dissolves the support material to reveal the completed model. The ABS plastic model can then be sanded and painted if required. ABS plastic is a durable, recyclable plastic used in applications such as motor vehicle bumper bars.

In the Fishbowl

A new home for Cofa's 3D printers in the Fishbowl 

Welcome to Fab-IT, the new blog for Digital Fabrication at Cofa, UNSW. FAb-IT replaces the Rapidology blog and expands it's 3d printing focus to include a wide range of digital fabrication processes, from front end data input to 3d model generation processes and physical object /performative outputs. We are interested in exploring the growing range of creative experimental processes associated with data capture, its processing and physical outputs across a range of materials.
The blog will also post links and  resources to help you explore the field. Sign up to follow ! Contributions are welcome. Please contact the moderator .

Printing in 3D

Printing in 3D 

3D printing machines use drawings created in CAD or 3D modelling software to fabricate models.There are a number of 3D printing technologies including Sterolithography, Selective Laser Sintering (SLS) and Fusion Deposition Modelling (FDM). The 'additive fabrication' device reads data from an .stl file to create directional print paths.The material is then deposited along the path to create the three dimensional object. Many 3D modelling software packages are able to export .stl files, either as part of the programme or as a plug-in. Software programmes used at Cofa for 3D printing include FormZ, Maya and Vectorworks.

Preparing an STL file
You need to supply your 3D drawing as an .stl computer file.
The STL file was registered by 3D Systems for their stereolithography CAD software. It has recently become the default file standard used by the Rapid prototyping industry. The Dimensions SST's inbuilt software, ‘Catalyst’ , processes an .stl file to create the paths along which the machine prints the liquid plastic. It will not accept any other type of file.

About .stl Files
The .stl file format comprises exclusively triangular polygons that describe the surface of a computer generated solid model. It is sometimes referred to as a triangular polymesh model. STL files can be created in either Ascii or Binary format. It is best to create a binary format .stl file. Binaries files are smaller than Ascii, a useful consideration as .stl files of complex geometries can become very large.
Your .stl file describe must describe a solid shape, that is, a completely enclosed object geometry that contains no holes. .stl files only describe surface geometry. They do not incorporate colour , texture or other attributes that may be supported by CAD software (some 3d printers are now able to read colour). .stl files are scale independent, however their resolution is not. A variety of CAD software packages handle the scaling of .stl files differently on export. The model can also be scaled larger of smaller by the 3d printer catalyst software, however no triangles will be subtracted or new triangles created.
For best results , create the object to the desired scale in the CAD or Modelling software, then triangulate the object to the resolution you require for printing during conversion to an .stl file. Some software packages incorporate .stl export modules which allow you to control such parameters. The dimensions of surface triangles should be in the vicinity of .25 and .5 mm to give the most detailed results on the Dimensions SST 3D printer.