Technology that was once only used by engineering firms to create prototypes has been finding its place in classrooms during the last few years. Since 2000, students at Indian Mound Middle School have used the program Autodesk Inventor to create 3-D computer-generated models, but it’s only been during the last two years that they have been able to see the finished product.
“I’ve always told kids in the past, ‘well, maybe when you get to high school, you’ll be able to take your design and build it or a few of you, if you’re an engineer, will use this program as adults,’” said IMMS technology education teacher Alan Kinnaman. “I was a little bit frustrated because we were building things that middle school kids couldn’t touch.”
He really wanted the students to have access to a 3-D printer so they could get physical copies of what they were creating through Autodesk Inventor, which is the same type of program used by professional engineers. The school currently has two 3-D printers for the technology education classes.
Last school year the IMMS borrowed a 3-D printer, which didn’t work too well, from the high school. During spring break Kinnaman asked Superintendent Scott Brown if there were any leftover funds to purchase a printer for the middle school; there was enough money to buy a $1,500 printer.
The second 3-D printer was received in January and paid for in part by the donorschoose.org funding website. Kinnaman said $300 of $2,000 was supplied by the district’s Project Lead the Way partner. The remainder of the cost was provided by 3-D printer company Makerbot Academy.
Commercial 3-D printers have been around for the last 20 years but it’s only been in the last few years that the printers have been found in classrooms due to the decrease in prices for the smaller models.
“We’ve been talking about robots in the middle schools for years,” Kinnaman said. “It’s the first robot we have that kids get it – this is making something for me. They come up here and it’s fascinating.”
By having the printing capability the students get more work out of using Autodesk Inventor. Kinnaman said having the practical application has made the program more fun to teach.
“One of the nice things about the 3-D printer is that it’s gender neutral,” Kinnaman said. “It’s not just pistons and gears. A lot of people use 3-D printers for jewelry or toys.”
At this point in the curriculum the students are not required to print a project as part of an assignment. Once they have finished the task for the class period, they can work on a 3-D printing task. Students may decide to print what they have created on the computer and Kinnaman said most of the children have decided to have a project printed.
Currently, Kinnaman does not charge the students to print items. In the future, there may be a nominal fee to cover the cost of the plastic filament used for printing.
How does it work?
The 3-D printing process begins with creating a two-dimensional sketch on Autodesk Inventor. They then extrude the sketch to create a three-dimensional rendering. Once the student is satisfied with the 3-D model, the file is saved as an STL (StereoLithography).
The file is transferred to the printer, which Kinnaman described as a large hot glue gun. A spool of plastic filament is then squeezed on to the printer bed in fine layers. After each layer is laid down, the bed drops a millimeter before adding the next layer. This layering process continues until the product is finished.
The time to print an item depends on how large the finished product will be. For something small, it could take 15 minutes while a more elaborate design could take up to six hours. With the newer printer, multiple items can be printed at the same time. However, Kinnaman pointed out if there is an error in printing one of the items, there will be problems creating all of the projects being printed.