The first step in building the R2D2 tin can robot is collecting a few things. This is my fourth one so I’m familiar with what I need for materials. The one luxury that we have these days is plenty of time. I’m not in a hurry. I have no deadline to meet. I’m going to enjoy every part of the build.
Before I get started, I want to share something with you:
I am a maker. Heaven on earth is noodling around in the workshop and casually working on my latest project. Time means nothing and there are no pressing concerns. I’m not in a hurry, and I’m “in the zone.” My workshop is my world. I am my own boss. There is a clock on the wall, but I don’t look at it. The enjoyment is in the doing.
I love CampQuestAZ. It gives me the chance to share the “maker” experience with the young campers. My R2D2 was only an example. They had to come up with their own design made from the parts I brought to camp. Check out the imaginative and creative robots they built!
Unlike their effort, I have a plan and the experience of building 3 previous R2D2s. So during my build today, I skipped around a bit. After collecting all of the necessary materials and tools, I cleaned and painted the can, the dome, the tiny liquor bottles, the air fresheners, and the dental floss container. All of the parts require a multiple coats. The base coat is black.
Next, I painted the can and the dome metallic silver. Finally, I masked a couple of small areas on the can and painted the can and the “arms” an off-white (ivory). The masked areas become the vents on the front of R2. The blue highlights are made of vinyl tape applied to a piece of plexiglass and cut out using an Exacto blade.
R2 is starting to take shape! All that remains is to add the wiring and electronics. They are amazingly simple. The model uses only 3 LED bulbs, 3 AA batteries, and a switch. Since the LEDs are different colors, each one will require its own current limiting resistor. The blue LED has a forward voltage drop of 2.8 V; the red LED drops 2.0V, and the “Rainbow” LED drops 2.5V. I calculated the resistance values needed to provide 20 mA through each of the LED (assuming a nominal power supply voltage of 4.5 V). The values only have to be in “the neighborhood. I chose an 85 Ohm resistor for the blue LED, a 100 Ohm resistor for the “Rainbow” LED, and a 125 Ohm resistor for the red LED. If you’re interested in how these calculations are done, leave me a comment.
Tomorrow, I’ll mount the three LEDs, install the battery holder and switch, and add a jack so that R2 can run from a USB converter instead of batteries.