Raspberry Pi and 3D printing seem to go together like peanut butter and raspberry jelly. There are so many different possibilities that inventors and innovators can come up with when combining these two brilliant technologies. We’ve seen uniquely created Raspberry Pi cases, as well as 3D printer control systems based on Raspberry Pi. Most interesting to me, however, are the 3D printed robots which use the device in order to operate.
We’ve covered numerous of these robots over the course of the past year or so, but none has been quite as unique as one which a high school computer teacher in Sydney, Australia has created. Tim Clark is always looking for ways to increase the engagement of his students. After all, that’s probably one of the main goals of most good teachers. Let’s face it though, most of today’s lesson plans are just flat out boring. Adhering to a school curriculum, while making lessons interesting and entertaining, is a huge challenge even for the best teachers. Clark, however, found the perfect solution.
“Last year my school purchased a 3D printer and I began to use it to create brackets for the Raspberry Pi computers that I was using in class,” Clark tells 3DPrint.com. “At some stage during the year I came up with the idea of starting the ‘jRobot Project’. The concept is for the school to create a number of robots that my students can dock their own Raspberry Pi onto, connect up with a few jumper straps and start programming.”
One of the stipulations for the jRobot Project is that the parts these robots are built from may cost a total of no more than $100. The first robot that Clark and his students created was the Apogee, but the latest robot created is the Drogerdy. The Drogerdy is a tank-style robot that runs off of Raspberry Pi. It got its name from an Aboriginal Dreamtime story about a clever little wombat, which Clark felt was suiting.
“The Drogerdy is designed as a tractor style robot which is modular and expandable,” Clark tells us. “The need for a tank style bot was important as it exposes my students to specific programming concepts in a new and interesting way. Currently the tracks run around a two cog assembly, but I have designed an expansion piece to enable the track to be almost twice as long.”
The lengthened track has not yet been tested but it will be soon. Clark tells us that when it came to 3D printing the Drogerdy, the hardest part was getting the tracks just right. He had to print them in such a way that they would not jam, but also have enough tolerance to cope with the different printing variations of the cogs and track assembly parts.
The body sections of the tank are designed so that they can be equipped with 5mm LEDs while also holding the batteries and motor controller. As for the electronics that make this little guy go, Rapsberry Pi is responsible for that. The unit is held onto the robot with stainless steel pins. The Raspberry A+ and B+ slide over them rather nicely and stay on perfectly while the robot is moving. The Rapsberry Pi is connected to the Adafruit Perma Proto Board’s header pins using female-to-female dupont cables. The proto board features status LEDs, a photoresistor, and an MCP3008 ADC IC, which feeds values to the Rpi from a Sharp IR distance sensor and the photoresistor. Of course this is all very complicated terminology unless you are into electronics.
Clark has plans to hook a couple phototransistors up so that the Drogerdy can follow lines. So far, he tells us, the robot has performed very well.
“It can motor along on quite a number of different surfaces, including carpet, timer floor, concrete, grass and gravel,” Clark explains. “It can drive over things that are up to 1/3 the height of its tracks, and probably more if I put rubber on it to give it more traction. At least one student has decided to use it as a basis for future development. He hopes to add LIDAR and use it to map a floor space.”
Clark has made the design files for the Drogerdy available on Thingiverse for anyone to download and build themselves, as well as some basic instructions. He used an UP! Mini 3D printer to print his, but mostly any FFF-based 3D printer should get the job done.
What do you think about this unique 3D printed robot? Have you tried printing and assembling one yourself? Discuss in the Drogerdy Tank Bot forum thread on 3DPB.com. Check out the video below of the Drogerdy in action.