This was a programme on in the late 60s/70s about a puppet and his job looking after a machine. There was a cuckoo involved called Yoo-Hoo (voiced by Ivan Owen, who later provided the voice of the much-loved Basil Brush), which laid eggs from time to time and they came down a sort of shute system of the machine. The song went something like this: "Billy Bean built a machine to see what it could do. He built it out of sticks and stones, and nuts and bolts and glue. The motor ran, chuttle-a-bang, ra-ta-ta-ta-ta-torator, And all of a sudden a picture appeared on the funny old cartoonerator." I have only ever met one person who remembered it and that was almost 50 years after it's viewing. Until she explained what she remembered, I thought I must have dreamt watching it!