15th April 2003

After much research I had decided to use polycarbonate as Electra's body material. It's particularly good at resisting impact, and is used as bullet-proof glass and vandal-proof bus shelters.

After much looking around on DIY web sites, I found what I needed at Technobots. I used 1mm polycarbonate.

Once the polycarbonate had arrived I couldn't wait to have a go at folding it into shape. I has read that once it gets heated up to 60 degrees its quite foldable, so after a vain search for one of those devices that we used to fold perspex with at school, I came up with the idea of heating some bailing wire on the hob, holding it close to the polycarbonate and then bending it before it cooled down. Only later was I to discover that you can cold-fold polycarbonate quite easily by sandwiching it between two hard flat surfaces and bending...

The new design gives even more protection to the inside, and allows a larger single hinge along the top rear edge of the robot. In fact the problem of the vulnerability of the flipper had been bypassed by making it smaller so that it now lies inside the bounds of the robot, resting on the side lips. This means that a horizontal spinner will hit the side of the body rather than the flipper/lid of the robot.

The sides are also tilted in so it doesn't rest on its side.

A couple of problems with this design was that all that overlapping polycarbonate made it rather heavy (about 40g out of a 150g weight limit).

I also realised once I got my wheels, which were 45mm diameter, that the body wasn't big enough to contain them. The wheels were actually bigger than I originally intended, they had become bigger to make the robot faster.

However, the polycarbonate was extremely stong, and could be thrown around the room to no effect, even without being bolted or glued together.