(Literally) Creating Engagement in the Classroom
I teach at the Turing School of Software & Design.
The Executive Director, Jeff Casimir, invested in a lot of tech-adjacent cool stuff that hangs out in the “Vault” room at Turing, including bins of Arduino boards and kits of parts like LEDs, resistors, motors, etc.. And a big-@$$ 3D printer.
When Jeff offered me the job at Turing, he probably could have offered me a lower starting salary just by uttering the words “we have a 3D printer”, but don’t tell him I said that.
From early November through the winter break ending 2017, if I wasn’t in the classroom, or helping students prepare for technical interviews, I was probably in the Vault, messing with the 3D printer. My first prints included “Om Nom” from the old “Cut the Rope” game, and a Baby Groot.
The prints weren’t great. Lots of “banding”, but this printer hadn’t seen a lot of use, or maintenance love, but for what we had, it was in really good shape. Of course, there was a fair share of nerdery going on as well for things like Star Trek icons, but I also got into designing and printing some “functional” prints that were more than trinkets to sit on a shelf. I printed a new shell for a failed power supply for the 3D printer that we replaced but had “mains power” exposed, and, well, I didn’t really want to electrocute any students…
But that got me to thinking about other ways we could embark on a more dynamic way of generating functional prints within the school.
Engagement Tools
In the classroom there are lots of ways to keep students engaged, and one technique we employ a lot are “draw a name” techniques. Essentially, we teach some theory, give students a few moments to think of an answer to a question, and draw a wooden tongue depressor with their name written in Sharpie marker. This ensures that (a) the students are paying attention, and (b) we see a random variety of students being called upon, instead of just opening a Q&A session where maybe the same few students ask the majority of the questions.
“Surely we can do better than wooden sticks and Sharpie marker to engage students,” I said to nobody in particular one day in January 2018, and with a little knowledge in my head, the 1801 Cohort at Turing became the first recipients of 3D printed “popsicle sticks”
By this time I was also thoroughly hooked on 3D printing, having made several Christmas gifts, a giant Mario “?” Cube suggestion box for Turing, and numerous other interesting things, and I ordered a 3D printer for my home which gets nearly daily use.
Another instructor at Turing took these initial blue popsicle sticks, painstakingly painted their names in gold paint, and then we had a hit on our hands. But there had to be a way to make popsicle sticks in a way that didn’t require hours and hours of painting detailed names.
Once my 3D printer arrived at home, a Prusa i3 MK3, I set out to find ways to utilize “multi-color” printing at specific layer heights, and my first results replaced the 1801 Cohort’s sticks from blue/gold to green/white.
Each popsicle stick took, on average, 20–25 minutes each.
This would lead to finding new color combinations for future cohorts along the way:
It would even lead to one staff member asking for their own popsicle stick big enough to beat people with for misspelling/mispronouncing her name. I won’t name names, though…
The Process
A mentor once gave me the phrase “humans are not scalable”, and the process of designing each of these popsicle sticks, laying them all out in my 3D printing software wasn’t a HUGE amount of time invested, but it was still several hours of work to get all of the student names each inning, generate the sticks, place them in the printing software, generate the code the printer uses to actually generate them, plus the many, many hours to actually print them.
The problem was, with large cohorts, I could only fit so many sticks on the print bed at the same time, resulting in many trays where I had to manually arrange the sticks to print. Sometimes they were too close and melted together. Sometimes they were too far away to fit as many on the printer as I could do optimally.
Automation (mostly) For the Win
Using some open-source software, called OpenSCAD, I was able to redesign the popsicle sticks in a slightly smaller format using a model created by Aaron Ciuffo and customize the scripting in his model to generate popsicle sticks.
30% less plastic (which is biodegradable, by the way!) than my previous process, but still 100% of the engagement in class!
I exported Aaron’s script to something I could import into Ruby and do a simple search-and-replace, allowing me to import a list of student names in CSV format, run a shell script to run my Ruby script, and output individual OpenSCAD scripts for each student. OpenSCAD, then, has command-line options for batch-producing the models, and thanks to modern hardware I can produce dozens of sticks in less than two minutes. This saved an enormous amount of time to generate the individual popsicle sticks, down to a few mere minutes to generate sticks for a whole class. But it would still take me even more minutes to manually arrange them to print crammed together on the print bed.
But, now I can edit a CSV file, enter one or more student names, generate a stick, drop it in my printer software, and export a few sticks at a time in less than 5 minutes. Each stick takes about 12 minutes to produce on the printer.
Can’t Stop, Won’t Stop
I wasn’t content. There had to be a way to make it even easier to place all of the popsicle sticks in one shot, and then it hit me.
What if OpenSCAD could take a list of student names, instead of one at a time, and lay out all of the sticks and export that as one big model instead of one model per student?
Turns out I could, and I could also tell the software to output the models *really* close together.
The result: instead of manually placing 16 or so sticks on the print bed with my old design, increased to 24 or so with my new design, now I can print 32 popsicle sticks on the print bed in one go. Generating this large 3D model takes about the same amount of time as generating 32 of them individually, but I’ve saved myself quite a lot of time having to lay them out in the printer software:
All I need to do then is insert the instruction to change the filament color at a given height, and we can send the file to the printer.
And the result was so great I even printed a 3D cup to hold them all:
6 hours, 32 staff members, about 11 minutes per stick. Half the time it would have taken previously.
The Dinosaur Lives Again
So what about that old, big, clunky 3D printer at Turing? Well, we got it some upgrades, and students are having fun printing their knick-knacks, but some of them are also printing functional prints as well. I run an occasional class to teach students how the 3D printer works, and get them involved in coming up with designs.
The new upgrades will also support multi-color layered prints as well but it takes more manual intervention than my MK3 at home.
In the meantime, rock on!
