What it should look like

29 March 2023

This was another 70th birthday present, this time from Linda.

The kit is from Kontax Engineering Ltd, a British company originally formed in 1964. According to their website they manufactured all of the parts for this engine in their own CNC equipped workshop at Maidenhead.

The Stirling engine itself was invented by Robert Stirling in 1816. It is basically a heat engine that is operated by the cyclic compression and expansion of air or other gas. In this particular model the glass dome is the hot side of the engine with the brass heatsink being the cold side. Heating is provided by a methylated spirit burner.

The kit comes with a 62 page instruction booklet. However it should be a straightforward build as the guidance is very clear, and each page quite compact.

5 April 2023

It's construction day. Working through the instructions is fairly brisk, partly because for some reason some of the work has already been done (base feet, 'O' rings, race bearings). Also, one step may tell you to screw in an item and the following step tells you to tighten it.

There are some areas where care is required, such as fitting the glass parts, but nothing too onerous. The fiddliest part is actually inserting the wick into the burner tube.

On completion lubricate the moving parts, add the meths to the burner, light the wick, wait a moment and then spin the flywheel. The engine purrs into life but stops very quickly afterwards. This may be because the wick was trimmed too long causing the flame to be too intense. As the wick supplied was rather too short for experimentation, order a replacement from Kontax.

8 April 2023

The replacement wick arrives today, so trim it, load the burner and wait the required 1 minute warm up period.

And shazam - it works!

Steam diversions

Like Parliament, the Stirling cycle engine is essentially driven by hot air. However I have always had a fascination with engines powered by steam. Like many of my vintage, I owned a model by Mamod. Although a toy, it was educational - mainly the repeated lesson not to touch hot surfaces. Mamod was founded in Birmingham in 1937 by Geoffrey Malins, hence (Ma)lin (Mod)els. Sadly the company closed down in 2024.

I also had another engine that somehow came with the workshop adjoining a house we moved to in 1965. This was a more aggressive piece of machinery that had seen plenty of action. Neither model survived our subsequent house moves.

More recent acquisitions include a Mamod Minor 1 from around 1978, and a Wilesco D407.

This latter is my only traction engine, acquired in 2001 for DM499 / €255 (this was the Deutsche Mark's farewell year)