Paste Extruder on a 3D Printer
We are developing an extruder for 3D printing solar cells, batteries, fuel cells, metals, polymers, and even food. We started with a syringe pump design.
This paste extruder incorporates open-source designs from the RepRap community, including but not limited to the Baricuda extruder, Structur3d, the RepRapPro Mendel and the Open-Source syringe pump project on appropedia. This work is supported by Hedron and volunteers of the Portland 3D Printing Lab meetup group. More pictures and details from previous meetups can be found at the older site “Hedron Paste Extruder Google Site“.
The kaolin:water print we made 20 days ago was printed on glass, covered with a wax cup, and then placed inside a dry place. It has numerous cracks. We were told to add Talc (magnesium silcate) which will act as both a lubricant (deflocculant) and a binder to prevent cracking. The drawback is that the melting point, maximum firing temperature, and strength is decreased (according to this Digitalfire Ceramics Technical article).
We printed with kaolin and water in a 1.52:1 ratio kaolin:water. Al Z. drew up a model for us to print out of clay. The syringe pump ran out of clay at the 95% mark just before the logo was visible so I reloaded the clay and resumed the print where it left off by editing the gcode. Mission succesful. Next week we take a break.
Today we printed an octopus out of clay. The picture below is after a week of drying.
Today we programmed the firmware on the RAMBO v1.2 board to reflect 1/2 microstepping on the OSAT syringe pump. This allowed us to get a few prints going. A couple of which collapsed miraculously. Videos to follow.
needle diameter: 1.3mm ; layer height: 1.0mm