By HaJo Franken

At the steam meeting in Wijchen in autumn 2019 I saw an extraordinary model that immediately attracted me. Research revealed that it was Patrick Stirling's traction engine after a patent drawing from 1859 and drawings by Julius de Waal (available here). There were no dimensions in the patent drawing, and the scale can only be estimated, about 1:12 to 1:15.

The original machine was never built.

For manufacturing reasons, I made the frame of the model out of aluminum instead of wood and built in round slides instead of flat slides. The flat slides (outside 7x6 mm) were too difficult to manufacture and adjust, so I used round slides.

The vehicle frame was made from aircraft plywood (photo below) due to the lack of 9 mm hardwood. In the course of further construction, however, this turned out to be too soft and difficulties arose with processing and accuracy of fit. Since no suitable wood could be found, I used aluminum.

Propulsion takes place via the large central wheel, which also serves as a flywheel. Without load, it runs nicely at a speed of 200 rpm with, unfortunately, not enough power to drive the model. This would also not be model-appropriate because at this minimum speed the model would cover 60 cm per second

Here are pictures of the finished model.

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