Programmable Robotic Car

The very latest in punchcard technology! No quickly outdated electronics, just pure mechanical goodness. This car can be given a punchcard of instructions in the form of smooth blocks, the pattern of which tells the car to go straight at one of two speeds or to turn right or left. Reprogramming is as simple as swapping some tiles on the card, so you can make an obstacle course and then try to program the car to successfully navigate all the turns.

It was inspired long ago by the LEGO Expert Builder 8888 ideas book. Brilliant concept, that: a mechanically programmable LEGO set!? Amazing. That system used racks to drive specific gears as they passed underneath. It was an inspiration for me at the time but the offset spacing of the 'reader' gears in that model meant that the punchcard *instructions* had to be similarly offset, which made programming it a confusing affair. What's more, racks only come in units of four, so fine control over the movement of the car was really hard. Here I finally sorted out how to use the clutch and smooth blocks to do the same basic task. It was a really fascinating build and it's a great deal of fun to play with.

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