In 2019 (prior to the pandemic) we started building a super-sized 5x working model of the cyber:bot for the educational conferences we attend. The project was shelved for a few years until this summer when we decided to simply get it finished for the many events we would attend. Our community has followed along with the development process with interest, so we’ve prepared this news post to provide a more detailed look at the construction of the super-sized cyber:bot.
The chassis is 3/16″ aluminum 6061 plates, cut on a waterjet at the local community college. It was TIG-welded in my garage to resemble the small chassis, which is .062″ aluminum 5052 from a CNC sheet metal break over a steel tool. Replicating the bent sheet metal edges with welding required using a filling rod, grinding, and sanding it down to have a smooth radius.
The solution for the printed circuit board (PCB) didn’t emerge so quickly. We considered all kinds of solutions including plywood, laser cutting, and laser-cut decals but the best solution was actually right in front of us. We spoke to the engineer who designed the cyber:bot PCB and he quickly ordered a 5x version for us. The realism of an actual PCB was a head-scratcher for many attendees at our first conference, as they wondered if the power switch really worked and if the 14-gauge “servo” wires were really connected to the motors.
The wheels were made on a Haas CNC milling machine by our partner DOCO Engineering in Red Bluff California. In a single day, Doug Pientak expanded the model, created the toolpaths, and made us four wheels.
Stephanie contributed tremendous skills to the build-up of the PCB and micro:bit module. Her notes sent to a friend summarize these efforts perfectly, so there they are:
“The edge connector is assembled from several pieces of wood cut, glued, and spray painted black. Ken was my expert make-to-order carpenter, with the portable table saw and compound miter saw he brought to the office! He made channels for me in its base plate, and a slot just under the top plate. I filled the slot and channels with black Sculpey clay (like Fimo) to set the wires in place. That’s 16 gauge jewelry wire I wrapped around a square stick and cut apart. It’s not a full 80 wires, but enough to visually read. I baked the edge connector in the kitchen oven for an hour to set the clay and hold the wires securely for travel, I hope!
The power plug, breadboard, headers, and servo ports are all wood. So is the micro:bit “pcb” – very fortunately right near Parallax there is a Rockler woodworking store, so we were able to get a very high quality 1/4″ furniture grade birch plywood and a few thicknesses of hardwood blocks. The switch and the top of the buttons are thin tin we cut out and grinded and sanded (I spent a LOT of time with the Dremel, my fave tool!).
The LEDs on the micro:bit are just the usual round case thru-hole variety press-fit into drilled holes in the plywood. I trimmed the leads and pushed them flat in a V formation, then used socketed jumper wires to add a resistor to each and then connected them to power and ground rails glued under the board. A 4AA battery pack is jumpered to the rails and secured to the chassis with Velcro. A flap of soft black craft foam covers the jumper wires to keep things tidy and out of sight. I spent several hours hand-cutting tiny strips of gold contact paper for the plated edge connector pads on the micro:bit, each one is essentially a sticker. The green triangles are actually masking tape – I was going to paint them on then realized the tape was the exact color, and makes a perfect clean line of course.
Ken mounted the motors to good plywood covering the servo cutouts in the chassis. The tail wheel ball we had, Ken drilled out the axle hole and I got a 1/2″ OD steel tube to line it with to reduce friction with the cotter pin I made from 1/8″ steel rod. Ken and Andy figured out all the wiring, and I think did a beautiful job tucking it all under the breadboard where it is hidden but easily accessible. Andy tuned and refined the code for really nice handling and deceleration suitable for the robot’s weight. We really had fun working on this thing. It took Ken, Andy, and myself three extra-long workdays and we made an absolute mess out of the office. Most fun I’ve had at work in ages!!”
Andy Lindsay prepared the electronics and programmed the tilt controller. It’s the same code used in our Learn.parallax.com tutorial.
The cyber:bot was the star of cyber.org’s EdCon 2023 in Phoenix last week. People took pictures with it, drove it around, and were drawn into see the real (small) cyber:bot.
Thank you for the excellent efforts on this project Michael, Andy, and Stephanie!
Ken Gracey
Parallax Inc.
