When Dr. Jozsef Gabor Kovács at Budapest University was commissioned to develop a fan the improved engine cooling and reduce noise he needed to make production representative prototypes for testing. A Stratasys Objet500 Connex 3D printer was used to create a simple tool made from their digital ABS photopolymer. It took 22 hours to print the three-piece tool.
The rapid injection molding tool was then run on 70 tonne injection molding machine and the material injected was POM (Polyoxymethylene also known as Acetyl). Given the accuracy normally required to bed out a standard injection molding tool I was surprised to the part come off the tool with little to no flash. The surface finish did appear a little rough in the video though and I wonder if it is enough to affect the results of the subsequent testing of the fan’s design requirements.
Stratasys has more information regarding 3D printed injection molding tools on their website.