Introduction: Robot Sumo Ring
This is a way to make Sumo rings for Robot Sumo. In this example, I am making Nanosumo rings, but this should apply to the larger classes of sumo. The final ring will have a black area for combat and a white ring for out of bounds. The white ring should be reflective so the down facing reflective sensors of the robot can see it.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Finding the Melamine at the Store
This is what I think is the hard part. Where the heck does Home Depot keep the small pieces of Melamine? Melamine is thin (1/4") particle board coated with plastic (which makes it like a white counter top). In the first photo, I show what the section looks like at Home Depot. The second photo is a picture of the board. This one is 2x4 feet and costs $10. The last photo is an "Easter Egg", a 2x2 feet lucky piece for $2. Since you are not going to make very many Sumo Rings (probably), a smaller piece is better.
In the case of the Nano Sumo Ring, I want to cut the board and get a 1x1 foot piece. I went to the Techhsop and used their Plywood Saw. Home Depot could also cut it for you.
Step 2: Masking, Painting, Cutting
This step is really 5 steps. Make a mask for the white area and stick it on, spray paint the whole piece flat black, then remove the mask. Then you cut off the corners with a band saw and the use a belt sander to make it round.
Here I used the Techshop Vinyl Cutter to make the "ring shape" mask. I made the input file to the Vinyl Cutter in Adobe Illustrator. Without really knowing Illustrator very well, I made a circle with diameter 19.25 cm and then made the .625 cm smaller circle for the boundary. I got the dimensions from the Robogames webpage for Sumo. Watch out. I subtracted .625 from 19.25 and got the wrong answer and wasted a lot of time. The inner circle diameter should be 19.25 - .625 - .625 = 18 cm.
Once I cut out the ring of Vinyl, I stuck it on the 1x1 foot piece of Melamine, and then I spray painted it with Flat Black Krylon paint. After it dried overnight, I pulled off the mask. I then went to the Techshop and cut the corners off with a Bandsaw. Then using the Belt Sander, I finished the ring.
The Belt Sander really gobbles up the board so it can be difficult to get a decent round shape. Don't use the scroll saw, it hammers the black surface and scrapes off the paint. Also, I couldn't cut a decent path with it. It was all jagged and bad, bad, bad.