Best practices for teaching design and manufacturing? MIT's department of mechanical engineering believes in hands-on learning. The top engineering undergraduates must sketch, model and manufacture a robot and then compete for prizes (and glory) at the end of the semester.
This year, Professor James Frey kicked off the class (called 2.007 and pronounced two-double-oh-seven and mandatory for all mechanical engineering students at MIT) by announcing the theme -- students were to design and build a robot to navigate a scaled-down country fair environment. "Robots will score points for dispensing tickets from a booth, ringing a bell on a high striker, inflating a balloon. Spinning a ferris wheel will multiply those earned points by up to 3x." Ripples of excitement spread throughout the lecture hall as young minds starting buzzing.
In one of the most popular classes at MIT, students are provided a copy of Solidworks and access to milling machines, 3D printers, CNC milles and lathes, and a water jet. In addition to 3 hours of dedicated machine shop time each week, students attend 1 hour of CAD modeling instruction and 3 hours of lecture covering topics ranging from programming microcontrollers to pneumatics and fluid dynamics to optimization techniques. Although sophomore Joseph Church worked at NASA the previous summer and had used 3D modeling tools before, he found that "having parts to actually model was all the motivation I needed to learn CAD." And learn they do.
Joe Church's 2.007 robot design (with "pseudo-holonomic" drive)
When asked to explain his design, Joe went into detail: My strategy was to lift the high striker weight and rotate the ferris wheel. I planned to accomplish these tasks with a mechanism that resembles a giant tape measure, and works like a forklift. Why such a strange mechanism? It seemed like a compact and elegant solution, as well as an interesting design challenge. The biggest challenge here was giving the strip of spring steel the longitudinal curvature needed for rigidity. I ended up heat treating it around a pipe over the burners of a very large stove in the basement of my dorm. Worked like a charm! As for the drive train, I wanted to have a “pseudo-holonomic” drive that would allow independent manipulation of the robot’s three d.o.f.s… without slipping. My hope was to have decent open loop positioning repeatability. This would allow me to repeat relatively complex trajectories during the autonomous period of the competition. I also thought it would be fun to design, and awesome to see the pivoting wheels in action. To control the robot, I thought it would be pretty quirky to send audible commands in the form of dtmf pulses from a modified touch tone telephone!
Ben Potash's innovative 2.007 robot design
Ben Potash, another MIT student in 2.007 this past spring, also uploaded his design to GrabCAD. Ben must have been happy when Stefan Varga, a highly respected GrabCAD engineer (with a GrabCAD score of over 8,000!) was nice enough to swing by and provide some high quality renders for Ben's model. Ben describes his robot a bit for us: This robot uses springs (not in the model) to fling the weight up to the bell using the basket on the front. It then backs up against the rims of the Ferris Wheel to spin it with friction (there is a timing belt transmission- also not included in the model). The robot runs on a 7.4V 500mA/Hr Lithium-Polymer Battery and is controlled using a wireless PS2 controller mapped through and Arduino Nano Microcontroller.
It's apparent that the engineers studying at MIT are creative, and, thanks to 2.007, going to be well versed in CAD design and rapid prototyping techniques. To watch some of these brilliant robots in action (and watch interviews with some of the top engineering students in the world), check out this video: (and see if you can spot robots from Ben and Joseph)
But before you watch the video, take the time to 'like' or 'tweet' this below. Your friends will thank you!
Although the next batch of 2.007 robots is many months away, we at GrabCAD are eager to see what next years students come up with.
