General
An opposed-piston engine is a two-stroke internal combustion engine where two pistons move toward each other within a single cylinder, with combustion occurring between them, eliminating the need for a cylinder head and valvetrain. This design offers superior thermal efficiency, higher power density, and reduced heat loss. Modern applications include marine, military, and emerging efficient automotive powertrains.
This model is based on the COMMER TS3 three-cylinder diesel truck engines, released in 1954, having a a single crankshaft beneath the centre of the cylinders with both pistons connected by levers.
Dimension: 176 x 47 x 141 mm (75% Model: 132 x 35 x 106  mm).
Weight: 0.19 kg (75% Model: 0.09 kg).


Printing
Print the 100% or 75% model.
Minimum build plate 180 x 180 mm.
I printed with PLA+, 0.16 mm layer height.
Avoid elephant feet and over extrusion.


Assembly
The attached pictures show all assembly steps. Assembly is in alphabetical order of the stl-file-name.
Make a three cylinder engine by printing 2 extra copies and join the three single engines using the "Engine Connection Pins.stl". Choose the crankshaft offset before glueing.
 

Operation
Turn the "Turning Knob" or  "Cranked Handle".