Requests for using the 3d printers have been coming in more steadily in recent days in advance of the Economics Shark Tank project and the Science Fair. While some of the applications of the 3d printer may be slightly off the mark, there is no better way to get to know how to use these printers then by trying to print…as long as they don’t take up too much material. We are using the Up! Mini printers and purchased 3 of them. It’s interesting to note that some of the parts used in the printer were made by the 3d printer. One of them had to be sent back because the head would not pass any filament. For now, we are keeping 2 of them to see how well they perform. We will purchase a 3rd one or more in time, but the brand will be up for discussion depending on our test runs.
Some of the products we have students printing include speaker prototypes, water bottle top prototypes, mug prototypes, nozzles, shinpads etc. This type of printer uses one type of filament and when it prints, it uses the same plastic (in our case we are using ABS plastic) to create all parts, including rafts and throwaway infill used to prop up portions of the piece. We can print approximately 6″x 6″ x 8″ tall and so far it has been relatively easy to use. The biggest issue we are coming up against with these printers is that objects that have large flat bases often have the corners curled up, which, in the best case scenario, leads to a curved bottom; in the worst case, the curved corner lifts up enough to interfere with the print head and then derails the whole printing process causing a mess of melted plastic. Advice we had been using is to spray the metal platform with hair spray, rubbing alcohol or cover the whole platform with painters tape for optimum performance. We soon realized that these techniques were more about removing the object with ease, however we are having the opposite problem – how can we keep the plastic adhered to the platform for the duration of a print?
We then looked into the temperature of the chamber and the platform. People with similar issues said that this particular printer’s platform did not get hot enough which caused the plastic to separate from the platform. We made adjustments to keep the chamber as warm as possible, but then also pre-heated the platform for approximately 30 mins to the preset 60 degrees Celsius. We noticed that the platform didn’t nearly get that hot, but it was a start. There were some discussion about a hack to make the platform achieve a higher temperature, but after manipulating the platform temperatures, we were able to get a better hold, but it still wasn’t perfect. Then after consultation with the upper school, they suggested two things. 1) make absolute certain that the platform is level before every print. 2) Simply use a coating of glue stick on the platform before printing. It turns out they were right on the money. The printers are more delicate than I imagined and even slight movement would get the platform out of level. Ensuring a level print right before sending the file to print allowed all the gaps, however small (1/10’s of a millimeter), to be minimized thus creating a level printing field. Using the glue, while making clean up a little more cumbersome then we’d like, worked very well and we were able to start churning out prints at a steady pace. As we continue, I wonder if residue from the glue on the platform will complicate future prints. Time will only tell.