Northwestern Students Give Their Concrete 3D Printer Its Own Test

by BuiltWorlds | May 23, 2016

Our favorite engineering students from Northwestern University have only two weeks left before their main event: the demonstration of their concrete 3D printer prototype. They're deep in the lab testing out what they'll showcase during their final demonstration. Now in their home-stretch, BuiltWorldsNU is tinkering away at working out the final kinks. Let's check in to see their progress this week:

Hello again!

It’s now t-minus 2 weeks until the BuiltWorldsNU team will unveil our completed prototype at our final presentation; we can almost feel the excitement building around campus. A lot has happened in a short time since our last post. After managing to convince our professors to begrudgingly push back the due date on our next report, we were finally able to conduct some tests with all systems working together. The following video shows one of our first attempts to perform an actual concrete extrusion:

Uploaded by BuiltWorlds on 2016-05-23.

Ex. A - stepper motor attached — **Ex. A - stepper motor attached**

As you may hear in the video, there was a little trouble with the control system so Andy had to step in and control the concrete delivery manually by touching some wires together. While not ideal, we were able to perform a successful extrusion with a relatively constant flow, and realized that if all else fails, we can ship Andy with the rest of the printer to BuiltWorlds as part of the final prototype. Perhaps the most important development in the last week, though, was a significant change to the design of our concrete delivery system. We have been using an electromechanical actuator to force extrusion, but due to several limitations of this solution we did some research and purchased a progressive cavity pump (see Exhibit A: in frame with stepper motor attached).

Exploded view - cavity pump model with frame and motor.png.jpg

Cavity pump model with frame and motor.png.jpg

We thought we were excited for it until we saw Prof. Beltran’s eyes light up thinking of all the things he could pump. We are now in the process of integrating the pump into our system so that we can continue testing and refinement of the full printer. Our next steps will be testing the new pump with concrete, integrating it with the control and positioning systems, and continually trying to avoid encasing ourselves and our belongings in concrete. It’s going to be a race to the finish, but we are getting closer and closer to our goal of building a fully functional device to demonstrate the concept of concrete additive manufacturing (that is, if we can actually get it out the door).