LT3D 3D Print Stirling Engine Kit

Download 3D printer files (.3mf format) here

Link to Prusa Printables page here

3D printed Stirling engine

This is a small kit of precision parts that allow you to make a surprisingly efficient and smooth running Stirling engine at a very low cost. The parts critical to an efficient Stirling engine, like an airtight piston and cylinder, precision ball-race bearings, and airtight displacer stem are all provided in this kit. You just need to 3D print the base unit and flywheel and then use the kit of parts to assemble your own Stirling engine. Print time is no more than a couple of hours and then assembly should be no more than 30 minutes. And as most 3D printers have heated beds, they are perfect for trying out your new engine. Heat the bed to 30° above the ambient room temperature, place the engine on for a few minutes and then give it a spin.

• You 3D print the 3 main parts
• We supply the remaining components that can't be printed
• You can run the engine on the 3D printer heated bed
• Also runs on heat cup of tea/coffee
• Needs about 30C+ temperature difference to operate
• Build a Stirling engine from home
• Requires a 3D Printer
• You can alter the design at home

How do Stirling engines work?

Stirling engines work by cyclically heating and cooling the air inside the main chamber. As the air heats up it expands, and as it cools down it contracts. This expansion and contraction drives a small piston which in turn drives the flywheel. The clever thing about Stirling engines is that the mechanism for cycling the heating and cooling of the air is built into the engine in the form of the displacer, which is driven by the flywheel and moves the air from the warm side to the cool side and back again over and over.

Heat Sources

• The engine is designed to run on a 3D printer bed set 30° above ambient room temperature.
• Other similar heat sources can be used but beware of warping the 3D printed parts with too much heat.

Main features:

• Low temperature difference Stirling Engine
• Built in flywheel balancing with ball bearings
• Regenerating displacer disc

Materials

• Stainless steel connecting rods
• Precision stainless steel ball-race bearings
• Low friction PEEK connecting rod bushes
• Micron precision borosilicate glass cylinder
• Extremely low friction self-lubricating graphite piston
• Brass gland and stainless steel displacer rod
• Silicone cylinder O ring seals
• Neoprene chamber gasket
• Stainless steel flywheel weights

Dimensions

• Base unit - 92mm diameter, 23mm high (3.62" x 0.9")
• Displacer - 70mm diameter, 7mm thick (2.75" x 0.27")
• Flywheel - 85mm diameter, 5mm thick (3.25" x 0.2")
• Power piston - 9.5mm diameter (0.375")
• Overall height - 130mm (5.11")

Instructions

Click the image below for PDF 3D printing, assembly, operation and maintenance instructions for this engine.