I have always been fascinated by miniature steam engines and have wanted to build one since I first began metal working. For years I searched for a design that was esthetically pleasing and one that didn’t require a compressor. Recently I found this beautiful design by Jan Ridders who was kind enough to share his plans with me.
This Stirling Engine uses neodymium magnets in the displacer and slide piston to control the return stroke of the displacer. A third magnet above the displacer balances the forces to minimize friction in the glass cylinder.
All pistons are made of graphite, the main cylinder is a Pyrex test tube, the engine is machined in brass and aluminum, the base is Corian and the flame uses isopropyl alcohol.
This video shows the engine in motion followed by a time-lapse of the build process.