This is part two in my ongoing series of articles on 3D printers for the classroom. Click here for part one.

I don’t know about you, but I have virtually no training in 3D modeling software. How should a classroom teacher start with their new 3D printer? Personally, when my printer arrived I spent a lot of time looking for cool designs online. The main repository I used and still use is the Thingiverse.¹

The best way to start with your new printer is to find some models that other people have created and printed successfully and print them your self. There are lots of great ones to choose from. Some of which are simply models for demonstration while others may be tools or puzzles. My printer came with two spools of plastic. I burned through them and called it professional development. I really did learn a lot from this. You should probably do the same thing. Print stuff because you think it might be fun, useful, or you just want to see how it prints. I think the nerd word for this is experiential learning.

The bottom line is, it doesn’t really matter what you print. Print small stuff, big stuff, stuff with lots of small details, stuff with overhangs. Start with the default settings on your machine, then change them to see how it affects the final print. This will begin to give you a sense for what you can print and what you can’t. I also kept a small scale handy so I could determine the mass of my prints and then figure out the material costs. If I buy a 1 kg spool of plastic for $48, then each gram of plastic used is 4.8 cents. So a 20 gram part costs about $1 in materials.

Don’t worry if you’ll never use these early prints in your classes. One of the first things I ever printed was a replacement cup holder for my Ford Focus. While it had nothing to do with teaching it did begin to show me the power of having access to a 3D printer. I also got my first experience with warping², a problem that plagued a lot of my early 3D printing.

During my learning process I did manage to print a few tools to be used for teaching, including a Macro Extension tube for my camera so I can take extreme closeups without having to buy a $400+ lens, an adapter to hold my iPhone to a telescope, an adapter for my Canon camera that works both with our telescope and our instructor microscope. But mostly I printed random stuff like an iPad sound reflector, games to play with my son, Higgs-Bosons, Pan Tail Duck call, and a bunch of other stuff.

If you feel you must print something useful try these:

• Triangle “Missing Square” Puzzle: It’s a good critical thinking exercise. Print one and play. You may have to do a little sanding to make it fit perfectly.
• Wind Puzzle: Not sure if this one is a Bernoulli effect demonstration or some other fluid dynamics principal. Either way it’s fun and my students love it.
• Microscope Mount for iPhone 5: I modified an iPhone telescope adapter to work with our student microscopes. If it doesn’t fit yours I’ll teach you how to modify it in a future post.
• One Small Step: Cool desk placard showing the first footstep on the moon on one side and the moon in relief on the reverse.
• Lincoln Life Mask: The Smithsonian is starting to publish 3D models of their artifacts online. You can see how the presidency aged one of our greatest leaders.
• Air Powered Rocket Car: This one presents good learning opportunities. It’s the first one I printed that required “supports”³.

Back to Part 1 or Continue to Part 3.

Footnotes:
1. Now I should say that many people have philosophical objections to the Thingiverse. Thingiverse was started by Makerbot. Makerbot had it’s origins in the Open Source Hardware movement. At some point Makerbot moved away from Open Source and was later bought by Stratasys, a large traditional 3D printing company. However you feel about Makerbot’s abandonment of Open Source or their later acquisition, the Thingiverse is a great place to find cool models to make.

2. Warping can happen with larger prints. The corners of the print lift off the build platform. Sometimes the part will still be usable, but more often it will not and sometimes can lead to the whole print coming unstuck resulting in a completely failed print job. I’ll talk about what to do to deal with warping in a future post.

3. FDM printers build from the bottom up. For some prints you will have parts that can not be printed because there is nothing below them to hold them up. Supports are typically a series of thin “walls” added below these areas, designed to be easily broken off the final print.