Random Bot: when sandwich containers attack

My first robot was from the excellent robot book by David Cook, "Robot building for beginners". It is a line following robot based on the LM393 chip, housed inside a plastic sandwich container called "Sandwich". Unlike many 'make your own robot' books this book covered just one robot in detail. The author goes into great detail not just on the electronics but also the construction techniques. The electronics level starts from a very basic level but always assumes you have a brain and you are happy to us it. Each chapter builds up the various sections necessary to make the robot. The author also covers other details such as DC motor operation, making wheel couplings, soldering, body construction, etc. In all an excellent intro to robot centric electronics, robot construction techniques and all the fundamental base skills needed for future robot building.

The main problem I had with Sandwich was getting the parts. All parts needed are detailed put being in Australia I had to find the Australian equivalent. For some parts this was easy (transistors, leds). Others were harder due to the lack of range in Australia (gear head motors, LDRs). Ordering from the USA wasn't an option due to the huge postage costs. The worst was a flat rate of $30US, regardless of the parts ordered. Of the Australian stores Jaycar was by far the best (in terms of range and staff help).

Due to the simple nature of the circuit there is no need to make a printed circuit board. Point to point wiring is fine, although but the end of the design my wiring was getting a bit messy.

When wiring gets messy. Also showing off the LDRs that track the line.

I used a plastic sandwich container as it was cheap (less than $1), easy to work with (read chop apart) and light but strong esp. with the lid on. I couldn't find any wheels so originally I used some old Mecanno pulleys with rubber band wheels. These were later replaced with some Tamiya wheels. The photo is of the first set of wheels.