3D Printing at CABE

With this process, the Ultimaker or Lulzbot extrudes molten material out of a small, heated nozzle based on your instructions. This mechanism is the similar to a hot glue gun, but the placement in 3D is what the robot offers. In the case of these machines, the material is a 3mm wide filament of thermoplastic Polylactic Acid (PLA.) PLA is very easy to print with and is non toxic. This machine moves in 3 axes: XYZ. Specifically the nozzle moves along 2 axes with the build plate and print on the third axis. The printer can place material anywhere in the build envelope as needed to produce your model. Our machines also have a heated glass build plate. Hot glass at 70°C is adhesive to PLA, but cold glass is not. When your print is done, the part should pop right off the bed.

This term is more difficult. The Vat in Vat Pho. refers to the pool of liquid material that the machine uses for stock. This material is a photopolymer, a liquid resin that turns into a solid when exposed to light. In this process the model is produced with an ultraviolet laser drawing each layer into the liquid. The UV begins the polymerization process, linking fluid monomers into long, solid, polymer chains. The chemistry is harder to grasp than simple melting plastic, but the results are fully dense objects of a higher quality. In our machines the vat has a window on the bottom and the laser shines up through this window into the vat. After each (XY) layer, the model is peeled off this window vertically (Z axis) into the air, and the machine prepares for another layer. 

There is a higher safety concern with this process. The uncured liquid resin is toxic to us. When handling the printer before or after a print, latex gloves need to be worn. The post processing of the finished parts also involves isopropanol with dissolved resin, so safety goggles are required. It is extra important that you do not use these machines without training, so the access to our Formlabs printer room is restricted until training is complete.