Remote Controlled Shark
In October 2000, I made a remote control shark, called “Gums” (“Jaws” with no teeth), which was about 1m long. It swam in a very fish-like way. I entered it into “Technogames 2001″, a televised competion (on BBC, since cancelled) to make robots do a variety of things (run, jump, climb ropes, etc.). It didn’t win the heat, but I enjoyed the experience. The race was televised on BBC2 in the UK on Tuesday 6th March 2001.
I used a single 1/4 scale servo motor to pull the tail back and forth using push rods. This was not powerful enough. If I made another swimming robot, I’d go for a MUCH more powerful motor. The motor, battery and electronics were housed in a waterproof box inside the body of the robot – the rest of the robot was completely immersed in water. I used rubber bellows to waterproof the rods that went through the wall of the box. The spine of the shark was made out of flexible plastic, as were the ribs. The skeleton was covered with a stretchy material I sewed to shape.
Here is a collection of photos of Gums. (The red stuff is petroleum jelly, which I used to waterproof many parts, especially the seal on the box).