Rhombic drive Stirling engines are held in high regard in the Stirling engine community. It is a mechanism of choice for a number of reasons. Firstly the mechanism is symmetrical, minimising any imbalances. Secondly unlike most con-rod arrangements pressure to and from the piston is never at an angle. With a conventional con-rod for a large part of the time the con-rod is at an angle. However with this engine the two con-rods ensure no twisting forces are applied to the piston which ensures low wear and low friction.

The displacer con-rod passes through the power piston providing a long gland which reduces wear. Again, forces the on displacer are straight and those lack of lateral forces reduce wear/friction. The through piston design makes this a Beta Style stirling engine.

Although technically a remarkable mechanism, it is also astoundingly attractive, probably because of the symmetry and the pulsating rhombic shape of the con-rods when it is running. It is undoubtedly a very attractive mechanism both static and running.



As with all the nano range it comes with a special burner, you just light the burner, let the engine heat up and then give the flywheel a small flick to start. The engine has borosilicate glass cylinders which can withstand high temperatures enabling you to glimpse inside the engine.

A low-friction graphite piston was utilised which is self-lubricating and requires no maintenance. A brass heat sink disperses heat from the cold side, while the rest of the engine is made from anodized aluminium.

This beautiful engine will run at over 1800 rpm on a tiny methylated spirit flame.

Design features:

Engine size	83mm x 50mm x 115mm (3.2in x 1.9in x 4.5in)
RPM	up to 1800rpm
Weight	TBA
Piston Diameter	9.5mm
Engine type	Beta engine
Stroke length	9 mm
Crank Design	Rhombic drive mechanism
Working temperature	About 200C / 390F
Bearings	Precision miniature ball race bearings
Materials	Mainly glass, brass, stainless steel, aluminium
Finish	Brass, anodised grey aluminium
Fuel	Denatured alcohol (methylated spirits)
Assembly	Preassembled
Required tools	None
Manufacture	Almost all parts CNC machined
Testing	Each engine tested before dispatch
Designed & Made in	England