About a year ago we decided to get a 3D printer. Although there are lots of pre-made options available, it’s much less expensive to get a RepRap Prusa I3 kit and build one yourself. The Prusa I3 is an open source 3D printer design that allows anybody to make components for it, and the community members, in turn, contribute plans for print heads, cases etc. It’s a pretty neat concept: The main controller is an Arduino mega board, the software is open source, and you can order the printer preassembled or as a DIY kit. This, of course, means that the printer can actually print parts for another printer, which can then go on to print parts for another, and so on.
We opted to put it together ourselves. The good news is that we learned a lot about 3D printing. The bad news is that it took a LOT of time. Building the kit, installing the software, and calibrating the printer took approximately 80 hours. Now, in fairness, some of that effort was also dedicated toward getting familiar with 3D printing in general.
Once we had the printer up and running, the first project was to create some extra parts for the printer. We started without cable guides, so we went to ThingVerse, found a design and voila! Next, we used ABS plastic to print a case for the controller boards as well as one for the power supply. Along the way, we learned a few valuable lessons.
Firstly, you need to buy a special ramps shield for your Arduino to interface with the various motors and sensors on the printer. Die-hard enthusiasts may opt to solder components to their own board, but we decided to buy a pre-made one and it worked great… well, initially. Because we were printing ABS, we needed to have a heated print bed, which is controlled via this board. After a week, the bed stopped working and upon closer inspection we noticed that the terminal for the heater had turned black.
A component on this board called a MOSFET was drawing a lot of current through it, and it obviously became very hot. It really should have had a heat sink on it, but the instructions online were not clear about this and the board didn’t come with one installed. So we ordered a new ramps and continued to print more parts for the printer. Before the cable chains were done, we had already had a wire failure on the head bed from repeated flexing. So what to print next?
How About a Full Size Chair?
Your first question might be: “How can you do that with a small desktop printer?” The answer comes from a group called Bits and Parts who created a open source design for a chair constructed from 85 individual puzzle pieces that interlock together.
It looked like a great way to use the printer for something utilitarian. Albeit reasonably simple, in retrospect it was a very time consuming project, because it required printing plastic supports for overhangs. Each of these took between 30 minutes and an hour to cut and file.
Other Printer Problems Along the Way
Like most DIY projects created from kits, we ran into a few issues with components. First, the cheap aluminum nozzle developed a second hole that rendered it unusable. We learned about a small shop in Pennsylvania that sells brass ones. The store’s proprietor is actually the designer of these heads, so it was worth the extra money spent. After installing it, we also needed to add a different thermistor because the original one differs from the one in the head. Things went great until the thermistor wire to the print nozzle broke (due to a bad cable routing that flexes too much) and the plastic assembly in the head melted. Again, we ordered a new part from the Pennsylvania shop, rewired the thermistor, did some calibration, and continued to print puzzle pieces when we had some spare time.
One day, however, we tried to turn on the printer and none of the components worked. After a lot of digging, we discovered that the kit’s cheap power supply had died. We replaced it with a higher-rated PC power supply. As a nice side bonus, it also reduced some of the printer noise.
Putting It All Together
Finally, after many hours hours of printing, sanding, finishing some broomsticks as chair legs, and some minor glueing and tweaking, we ended up with a complete chair. It looks great in the living room, and yes, you can sit in it!