This is the second year with my 3D printers. I have learned a great deal in the two school years of 3D printing and feel I am ready to pass on some wisdom. I am by no means a 3D printing expert. What I have now, if anything, is something I was looking for when I first started this journey: A tool box of tips and tricks to make life with 3D printers in the classroom just a little easier and maybe some advice for teachers considering diving in.
The 3D unit I completed this year comprised of two classes of 40 8th graders (for a total of 80 students). These are intermediate/advanced computer science students who have taken computer elective for three years at our middle school technology magnet. I started the unit by teaching the students TinkerCAD. I used the tutorials that are built into TinkerCAD, and find that I need little else to teach 3D design at this level. (Our students have worked in Sketch Up earlier in the program, but that would not be necessary for this lesson.) I held the students accountable by having them turn in sceenshots of the completed TinkerCAD designs in a Google template. I choose a series of 15 tutorials that I felt covered the most important skills. In the beginning, I guided the students, but they quickly moved beyond needing my guidance and began to move at their own pace because the TinkerCAD tutorials are very self-explanatory. I spent my time working the room, challenging the students and making sure they understood. I found they could work through all the tutorials within a week (most students completed all 41 tutorials).
Last year we created robots. I had so many challenges with that unit. I loved the outcome but I felt that overall the final designs were not completely successful. The students did not understand fully how to create moving parts (although they did understand 3D design). Very few of the robotic parts from the student robots moved. Many broke, fused, or were the wrong size. While I believe students learn from failure, and I do think we would have eventually have been successful, with 80 students, reprinting over and over to get it right just wasn’t realistic.
While at the CUE conference I heard a suggestion about a 3D lesson for designing earbud holders. It sounded like a great idea. After some research, I discovered that there are many such designs on the web, so I had some examples to start from. I realized what I was missing in my lesson last year was teaching the kids scale measurements.
Earbud Modeling Lesson
1. Planning: I passed out graph paper and rulers with millimeters. Using a document camera, I showed the kids how to draw a scale on the paper, marking off 0-100 mm by 10s. I had them draw a 40 x 40 square. That was the base for their design. After doing some measurements, we discovered that the holes for the earbuds needed to be 5-10 mm in diameter. The students designed their earbud holder on the paper.
2. 3D Modeling: After the paper design, the students created the earbud design in TinkerCAD using the same measurements as the drawing. For many students, this was the first time they had made the connection of planning something on paper and transferring the same scale to the computer. Because the image looks a completely different size in TinkerCAD, this was a real ‘Ah Ha’ moment for many of them!
3. 3D Printing: The students download the file and then saved the .stl to Google Classroom. Since our district has implemented GAFE (Google Apps for Education), downloading and printing .stl files has become 1000 times easier (See my tips at the bottom of the post). I had some volunteer students come in before school to help with the printing, but I still did the majority of the printing.
Results: They turned out amazing! Because they were not too thick and I could print multiple designs at a time, I was able to print two for each student. One to take home and one to hang up for open house! I’m very happy with this lesson and the kids absolutely loved their earbud holders.
Suggestions: I told the students to make them 6-8mm thick, next time we will make them 5mm thick for quicker printing. 5mm is still a good thickness. Remind the students that the design should be flat on the workspace. If they are flat, you do not need to print with supports or a raft and you get much better prints.
3D Printing Tips
I have two Makerbot Minis and three Robo 3Ds I like both brands for different reasons. They both have strengths and weaknesses in a classroom. Here are some things I have learned about 3D printing in general:
- Workflow: If you have GAFE, it is a life saver! I created a Google classroom assignment and had the kids turn in the STL files there. I created a spreadsheet with all the students and as I downloaded the files to print I made notes. Last year, I really struggled with how to get files to the dedicated laptops. I used flash drives, shared folders on the server, and a few other methods. Google Drive is by far the best method so far.
- Keep the printers plugged in to the computers and turned on. Once I stopped turning them off every night, I saved a lot of time and frustration trying to get the printers to connect to the computers.
- Take the filament out of the extruder when you are done with printing. You will have fewer jams.
- Use a clear spray paint before you try to paint prints. The paint will stick better
- Use diamond files or wood blocks covered with sand paper to smooth out prints.
- The Robo 3Ds work better if you oil the filament. I don’t know if other printers work this way. If you are having a lot of jams, it is worth looking into. I printed an oiler I found on Thiniverse and I have not had a jam since (in the Robos).
- BrainPop has a great intro lesson on 3D printing with activities.
Linda McClure was featured on the TinkerCAD blog as a Tinkerstar, April 2016
Categories: 3D Printing