First Day with my 3D Printer

Thank you MakerBot, thank you DonorsChoose, thank you anyone who contributed to make this deal possible. Yesterday afternoon my Replicator 2 arrived.

MakerBot has announced a desire to have a 3D printer (one of theirs, of course) in each public school in America. They've partnered with DonorsChoose.org to offer their printers for an incredibly low out-of-pocket cost to teachers. More details on that in my previous post 3D Printing. Funding isn't unlimited, so the first time they offered, I wasn't able to get it. Second round of funding I managed to get in. Now many teachers are waiting for a third round of funding. But that's a different story.

My printer, a MakerBot Replicator 2, was funded just under two weeks ago, and the actual printer arrived at my school Monday afternoon. I decided to set it up with my Calculus class today.

I brought the box up to my classroom and cleared enough space on my desk for the printer, which is roughly the size of a microwave oven. I unpacked the boxes, put the printer on my desk, and began working through the startup procedures in the user guide. I was not very far along when the period bell rang, and my students began filtering into the room.

I had mentioned the printer to them, and many immediately realized what that big black thing on my desk was. I was peppered with questions, which made it hard to continue setting up. I assigned tasks to students. Snake the power cord to the outlet. Work through the interface menus. Load the PLA filament (the "ink" the printer extrudes to do it's work). I really wanted to do it myself, but I also knew that my students would get a huge thrill out of helping.

Finally, set up, the question was what to print. I wanted to start small, since I don't know much about the machine. My students wanted to start big. The two most frequent requests were for Hello Kitty items, and Pokemon goods. They also read the news, and so there were a number of questions about printed guns. I brushed all suggestions aside (one benefit of being the teacher) and announced we would print one of the projects pre-loaded on the SD card that came with the Replicator. We looked through the items and decided on a flexible bracelet.

Go. It is so cool. The PLA filament feeds up from a spool hanging on the back, gets to the extruder, which melts it at 240 degrees C, and the gantry system maneuvers the extruder around to squirt out the design. We just started looking at Integrals, and I was really happy that all the students were watching us build up something from very very very thin layers (not really infinitessimally thin, but I think it was good enough to make the abstract idea concrete). It took about 20 minutes, but most of the students' eyes were glued to the printer for the entire process.

When done, I took the bracelet from the build plate and passed it around for students to inspect. It is amazing technology. I did a random number drawing (thank you TI-Nspire) to see who got to keep the bracelet. I had as many boys as girls interested in the bracelet.

Next we tried to print some chain links. This didn't go well. Partly through the build, the item separated from the build plate, which effectively ruined the job, so I cancelled.

Third we tried a fish-shaped fob called Mr. Jaws. This also took about 20 minutes, and we did another random number drawing to decide who kept it. I made an effort to lecture for a very short time, connecting yesterday's lesson about approximating the area under a function by drawing many thin rectangles. They weren't interested.  So I began a fourth print job. This one was a nut and bolt. I couldn't believe the threads would actually work.

The period bell rang, and the students left, but I could see it was one of the most interesting classes ever for them, even though we did very little formal learning.

The nut and bolt eventually finished printing. I removed them from the build plate, and broke off the thin plastic the forms at the beginning and end of print. Twisting them together I found that, though tight, the threads actually worked -- the Replicator had printed a useable nut/bolt combination. Playing with it through the day, it got better and better. I suppose it wore off rough places in the build.

Later in the day we tried to print a comb. This item, too, came loose from the build plate, and so was ruined.

So, the question going forward, is how to use this effectively in class. I need to learn how to design things on my own. I cannot rely solely on other people's postings on thingiverse.com. I need to figure out why some items come loose during printing, and prevent that from happening. Math for America is going to offer a PLT in 3D printing this spring, which I intend to sign up for. In the meantime, I suppose I'll have to find some online user groups and begin studying.