Topic Tag: 3D printing

Hi there! I've been following Precious Plastic for about a year now and I have to say, it's a wonderful project! One, I'd like to contribute to at some point. Currently, I'm in my last year of industrial design studies and I'll start soon my Bachelors Thesis on designing a 3D-printable monocoque frame for an electric scooter. I'm planning to actually print & test the frame next spring/summer. As my primary tool I will use my Hangprinter, that I've been developing the past 1.5 years. The Hangprinter is a frameless printer-concept by Torbjorn Ludvigsen. The printer consists of a base unit with all the electronics and motion mechanics, and three anchor points on ground level for dyneema lines, which are used to position the print head. It is a quite unique concept, but foremost it is easily scalable to (theoretically) any size needed by only extending the lines. For more detailed information you can head over to www.hangprinter.org There is also plenty of information on the RepRap Forum My printer has currently a 2.5 m tall tetrahedron frame, a heated print surface and the e3d-online SuperVolcano filament extruder attached to it. I did this summer two big print projects on it. One was a giant high heel for a finnish shoe designer and for the other project we printed the shell parts of a prototype robot. What I learned, was that the current FDM-technology is far too slow for a printer this big and of course that in long term it is not viable to print anything else than waste plastic. This is also the reason, I've been interested in Precious Plastic. You guys have come up with nice machinery for shredding and extruding plastics. If you want to print with waste plastic, the first step is to shred it. My initial thought was to make my own filament, but after second thoughts I realized, that it is just a unnecessary step. So, I began to study commercial pellet extruders and their open source counterparts. Finally, I designed my own extruder and I'm now in short time getting it ready for testing. Tech specs are as followed: Weight: 4.5kg Length: 550mm Effective screw length: 225mm Heating: 3 x 180W /230V First, I'm going to test commercially available recycled HDPE and PP pellets in order to rule out issues caused by raw material impurities and quality, but eventually my plan is to test shredded flakes. I know that both HDPE and PP are going to be really tough to print due to their heavy warping properties. That is something, that can possibly be addressed only by a controlled heat chamber. But before that is going to be on my todo list, my idea is to mix chopped carbon fibers into the polymer. Fiber-enhanced polymers usually print nicely, since the warping is mostly eliminated. I'm hoping this will be the case also with HDPE and PP. The printer frame is going to need an update to be able to handle the stress caused by the pellet extruder. I already have a new set of BLDC-motors with rotary encoders, that will do the heavy lifting. Each of them is rated with 1.8kW and there will be 4 of them in total. Also new Dyneema line is on the way. A single line will be able to lift around 140kg. The whole system runs on a Duet 2 Wifi controller and ODrive BDLC-driverboards. So, what do think? Do you have any questions, feedback, etc.? Do you think this setup could be beneficial for Precious Plastic?