On Tuesday the 28th of October the annual science fair at the faculty of industrial design was held. We displayed the printer and most of the testprints we made. We were not allowed to do any welding at the science fair for obvious reasons so we showed a video of the working printer.
Many people were interested in the design of the printer and we’ve got a lot of positive feedback. We received questions on how the printer works. Questions like: “where does the metal come from?” and “What software do you use?”. And some people had suggestions on improving the design. For example, the use of water for cooling.
The printer got the amount of attention that we were hoping for which made the science fair a nice way to end the project.
This post will feature the BOM of our 3D printer. The base for our printer is a prusa i3 kit. This is a well documented design so we will not name all the parts that it contains. The build manual can be found on http://reprap.org/wiki/Prusa_i3_Build_Manual. The modifications to the original prusa design are quite simple. In place of the print bed we used a box constructed of sheetmetal. This box is isolated on the inside with a material that is normally used in ovens, the material contains vermiculite and is commonly available. The plate on which we weld lies in this box and is connected to the ground cable of the MIG welder by a piece of threaded rod, this rod goes through the box and the isolation material. Make sure to electrically isolate this bolt from the sheetmetal box. We did this by making a small “washer” out of wood.
We used an aluminium extruder carriage which we ordered at reprapworld. It is best to use a metal carriage since a lot of the heat from the welding will go upward and this might damage a plastic carriage over time. The torch holder is made from a small block of aluminium, we used a mill to fabricate this part but it can also be made with a pillar drill and a saw. Continue reading
On Tuesday the 7th we went to metaallokaal, a metal workshop, to play around with some MIG welders and to get additional information on the welding process. Jeroen, the owner of metaallokaal, gave us some advice on which settings to use. During the instruction our group had a collective eureka moment when Jeroen demonstrated a “wrong” setting for the MIG welder. The feed rate and the power setting were both too low to weld on to the thick plate.