Clockwork: Building Cogs.

Last week we began designing cogs to be used in the set for Clockwork. Initially I decided that the quickest way to make up a number of them to work with would be to spend a bit of time designing one really accurate cog, and then use it as a template to mass produce more.

I therefore looked for a circular object large enough and drew around it on a thick piece of plywood. As we had never made cogs before we considered what would be the best way to get an accurate design drawn up. We had our circle drawn on the wood and next we had to consider how we would make the teeth. All had to be the same size, and also the gaps between the teeth had to allow the same shape into them, as a cog would work.

The way I decided to design them was to measure the circumference of the circle and then divide it up into a number that was large enough to fit the right number of teeth all the way around the circle. We also left a gap either side of the teeth so that the teeth of another cog would fit in smoothly. Basically we measured five centimetres for each tooth of the cog and left a centimetre gap either side of the teeth.

Once we had marked up the measurements for the teeth I drew a line across the circle to the mark opposite. This divided up the circle so that we could draw out the teeth accurately, as is shown above. At this point we cut out the circle of the gear, planning to cut the individual teeth out after and with more ease.

With the cog cut down to its circle we began to work with a jigsaw to cut out the individual teeth accurately and precisely. Once this was done we had our first cog shape and would be able to use it to stencil more

and quickly make more.

Above you can see the first completed cog, as we were unsure whether they would be stationary or move whist hung we decided to cut out the circle in the middle to give us the option. As the circle hadn't been drawn but had formed as a result of the lines we had drawn across the surface this gave us the impression we had been more or less spot on with our accuracy.

Once the circle was cut out the middle of our experimental cog we began to increase in the rate of our work. Although at first we had taken our time to create an accurate shape, this had been completely necessary and we could now not only use this cog to quickly make more, but also put into practise what we had learnt to make cogs of varying sizes. Which we avoided at first, preffering to get one right before branching out and over complicating things.

With each cog completed we painted them with a black base coat. As they became incredibly easy to make we bashed out about six that day including two that were joined together permanently, as is shown below.

Originally these two cogs had simply been drawn very close together to fit as many on the wood as possible. However, we decided whilst cutting them out leave them attached together. Rather than struggle to hang them perfectly next to each other we could keep them left attached and give the same appearance. Even here on the ground they look like they have just been placed next to each other.

As we had spent all day in the workshop I took the cogs to finish off at home with a dry brushing technique I had developed during Sweeney Todd. This was very useful as I could quickly paint up a large number of pieces to a standard high enough to be viewed hanging from the rig in the theatre. Here I experimented with a look that made the cogs looked wooden but flickered like brass. One PT student even asked me what they were made of, which I was pleased to hear as it meant we would be able to convincingly make them look like they had been constructed of a different material to wood. For this batch I tried out a number of variants that all gave an oaky, yet brass look to them. I think for the next few I will try something colder, more silvery and steel-like, but for the mean time I was happy with what we had achieved and learnt, especially from experimenting with new techniques we had to develop ourselves as we went along.