I’ve spent four weeks now preparing and attempting to print an object on a MakerBot Thing-O-Matic 3D printer. I haven’t been able to convince the printer to connect with my laptop, let alone print something, so it was starting to feel like an impossible task. I badly needed some inspiration.
While I’ve been working with the Thing-O-Matic, which is an older MakerBot printer that dates to 2010, another 3D printing relic has been staring me down. Noisebridge owns a RepRap: the do-it-yourself printer that started the hobby 3D printer movement back in 2005.
Noisebridge’s particular model is a Prusa Mendel, which was first invented in 2010. RepRap isn’t a company; it’s an open-source movement. That means you have to build one yourself (or buy a completed machine from someone else).
Over four weeks at Noisebridge, I saw the machine transform from broken to tenuously working to working. Progress was marked in the bits of discarded electronics and plastic scraps I found at the 3D printer stand each week. A friend advised me that the RepRap guru responsible for fixing the machine was making appearances at 3D Thursdays, Noisebridge’s weekly meeting for people interested in 3D printing and related technologies.
RepRaps are very technical machines. After my failures with the Thing-O-Matic, it didn’t sound like a good idea to dive into something even more complex without the right training. I found the guru this Thursday and we got to work right away on a print job. His plan is to rebuild the Prusa into a Mendel90, which is an easier-to-use RepRap. All of the controls will be browser-based, negating the need for complicated software.
RepRaps were born out of a very interesting goal: creating a machine that can replicate itself. They’re not there yet, but they draw closer all the time. The Prusa has a number of 3D printed parts, including pieces that secure its metal rods together and a gear that controls the extrusion of filament. We decided to print a few of the pieces it needs to be upgraded to a Mendel90.
We needed two open source software programs to get the printer printing. Slic3r takes your 3D design and cuts it up into the layers the 3D printer will print. It also calculates all kinds of information the printer will need, such as how much material is necessary and the path to take to lay down the layers in the most efficient way possible. It presents all of this information as code in a confusing looking document.
The second piece of software is called Pronterface. It controls the Prusa, including the location of the print head and the speed at which the filament is extruded.
Everything looked good, so we started the print job. I’m beginning to think I’m bad luck around 3D printers, because almost immediately we ran into problems. The printer wasn’t starting to print and we didn’t know why.
After messing around with the electronics and resetting the printer a few times, it was discovered in the code that the printer was hitting its maximum temperature of around 205 degrees Celsius and then shutting down to prevent itself from overheating. The print head is secured in place by a 3D printed part made of PLA plastic. If that gets too hot, it can melt. The print temperature had been set around 200 degrees. The printer had been oscillating back in forth in temperature to hit that mark, but as it oscillated up it neared the dangerous mark of 205 degrees, causing it to shut down.
We set the printer to print at a few degrees cooler. Almost immediately, it began printing.
But we weren’t done yet. We needed to make sure the print bed was at the right height. The print nozzle was too close to the bed, which meant that no filament was coming out. We moved the bed down slightly and a thin stream of plastic began issuing from the nozzle.
Save for a piece of plastic that curled slightly as it cooled during the first layer of the print, everything printed without a hitch. After about an hour and a half, we had two new RepRap parts in Noisebridge-red plastic.
I didn’t have much control over setting up the print job and was very grateful to have someone to overcome all of the problems for me. Despite my few contributions, it still felt gratifying to watch those pieces build up layer-by-layer. I’m not yet ready to work with the RepRap on my own, but I feel more motivated now to go back to wrestling with the Thing-O-Matic. Wish me luck.