You guessed it, it was another oscillating engine. This time, it was designed using a free 3D CAD package for the PC.
As I said, I thought I'd better start off small scale and simple to ease me back into the hobby as I hadn't touched the machines in about 8-9 years.
This was done in January 2007 using my old lathe and milling machine though and I really struggled with those machines. It was an old portass lathe and a dore-westbury milling machine that someone had made. I guess with some quality time and care spent on the machines they could have been very good, but I was too impatient for that, I wanted to make models, not mess around with machine tools.
Nevertheless, the engine came out well, apart from some of the surface finishing. I made a glaring error in the design stage that means when the crank is at 90 deg, the cylinder uncovers part of the port, letting air escape! This doesn't affect how the engine runs, but it's very wasteful! This can be rectified by using slightly larger stock for the cylinder.
