The 3D printing of large scale molds for vacuum injection has many potential advantages when compared to CNC milling or injection molding. There is a lot of research and development taking place in the area of 3D printing with thermoplastics worldwide. It can be cheaper, faster and more environmentally friendly than the conventional production methods. A big advantage of thermoplastics is that they can be reused, which means molds for small series (or one-offs) don’t have to be thrown away. Consortium partner Nedcam Solutions, a leader in the world of 3D shaping, challenged NHL Stenden student Eelke Veeninga (mechanical engineering) to build a working prototype set-up of a robot arm that’s able to print 3D models.
The set-up contains a UR5 robot arm with an extruder head (Titan Aero) and a computer with the necessary software. A custom attachment was built to connect the extruder head to the UR5. RoboDK software is used to operate the UR5, using the data for the 3D model from Slic3r software. RoboDK does not have an option to operate an extruder head. Quite some time was used to solve this problem using the PLC of the UR5. An Arduino Mega is used to set the extruding speed to the values calculated by RoboDK and to monitor and control the temperature of the extruders nozzle. The picture blow shows a simulation of the printing of a model in the RoboDK software.
The set-up can successfully print 3D models. Even models that, on a higher level, reach outside the printing bed can be printed because of the reach and flexibility of the robot arm (as seen in the picture below). Printing speed is unfortunately still limited by the step motor used in the extruder head.