This week we went to the College of Engineering Design Lab for a demonstration of their 3D printer, 3D scanner and CNC Mill & Lathe. Steve Struckman was our amazing tour guide. He showed us all three machines as well as finished products from all three (with the scanner the finished product is a computer file).
There’s a piece of sandstone inside the 3D
scanner (bottom left). The computer screen shows the rendered file. The information in the STL file
can then be entered into the 3D
printer. This stage is skipped if you have created a file from scratch (through CAD
software, from an MRI
That’s a model of a claw from the Iowa Giant Sloth
sitting on top of the printer that the Lab made for the University of Iowa Museum of Natural History
. Most of the lab’s work is for the University of Iowa Hospitals and Clinics, but they do projects for any department and the public can bring in projects for the printer as well ($8/cubic inch). Thinking about a 3D
printer for your library? This one costs $35,000.
Samples of things the printer can make. It made the wheels for a College of Engineering student’s senior design project while we were there. It took about 40 minutes to make the wheels. Each layer is 1/10,000 of an inch thick. Imagine how many layers are in the prosthesis or back muscle! The layers are made of plastic that is melted (think of a glue gun) and sprayed in place. The cartridges look quite a bit like regular printer cartridges (but a lot bigger). The printer we saw can only do one colour at a time. They can change cartridges part way through a project to create multicoloured layers (example at bottom of post).
When they come out of the printer, pieces are given a special hot bath to remove any of the support plastic. Here is the body of the car taking its bath.
Sometimes the object that comes out of the 3D printer is used to determine how to make something out of a different material. The computer file can be used to make the object with the CNC Mill & Lathe out of metal or other plastics. Unfortunately, we were not able to see this machine in action. He ran the program for the just-completed model car chassis on the computer screen so we could see how it would work. The lab does have manual lathes as well and Mr. Struckman still believes it is important for the students to learn how to use these for a better understanding of what the CNC (computer numerical control) Mill & Lathe is doing. He also stressed the importance of trigonometry and being able to visualize things in 3D.
Then we did a quick walk through the rest of the lab to look at some very traditional tools like metal cutters. It took us awhile to wrap our heads around the EDM (electrical discharging machine). This machine sends electrical pulses through graphite which then makes holes in metal. The piece of metal sits in an oil bath and the metal bits dissolve into it. The machine was not working when we were there and many of us got hung up on the fact that graphite is so much softer than metal. I hope I am describing it somewhat accurately!
And each kid received a 3D
Tigerhawk to take home! This was an amazing field trip and one that I hope to repeat in the future. While the kids saw the video of the 3D printer
earlier, seeing how all the machines work together and the samples, not to mention seeing the grin on Mr. Struckman’s face when describing some of his favourite projects was a whole different experience. Many businesses (even jewelry stores) own them as well as universities so almost any community probably has one that children could visit.