ERLE Tek

Joining an emerging start-up building construction 3D printers, the lack of mechanical engineers on the team meant that electrical engineers, civil engineers, and the business operations team handled the CAD design of the robot. I wanted to create an overarching CAD assembly for the robotic 3D concrete printer to manage changes, complete motion assemblies, and design more accurate parts for the future. Measuring existing parts in the prototype, I created an assembly with 60+ unique parts, ensuring accuracy using calipers. When designing and implementing new parts, the overall CAD assembly was used to verify fit. 

While testing the prototype of the robot, a problem we ran into was the slow print speed. The concrete would not extrude out of the printhead at the desired speed, causing problems forming and building the concrete layers properly. I identified the problems as being associated with the design of the printhead itself. There was not enough pressure being generated to rely solely on the gravitational force to push the concrete downwards and out. I tried to come up with a mechanical solution to push and extrude the concrete. Looking into several dispensing mechanism designs, I decided to use an Archimedes screw. A major reason for this is its ability to move concrete forward to extrude, but also mix and distribute concrete in the back of the printhead. This prevented concrete from solidifying too early, which greatly reduced extrusion speed.