Model Steam Engine & How It Works - 3D Printed (4K)

[tsbrownie]

These are called wobblers or oscillating cylinder engines. When I was younger you could buy plans to make one of these from ads in the back of any kid's magazine. Most people used brass or similar. When my son got a 3D printer, I thought it would be fun to print one. The piston in this one is about 5x the diameter of a brass one I made about 20 years ago.

This one won't run on steam, that temperature would deform or melt the plastic, but it will run on compressed air!

From Wikipedia, the free encyclopedia (edited)

An oscillating cylinder steam engine (also known as a wobbler in the US) is a simple steam-engine design, proposed by William Murdoch at the end of 18th century, that is valved by the rocking motion of the cylinder.

Oscillating cylinder steam engines are now mainly used in toys and models but, in the past, have been used in full-size working engines, mainly on ships and small stationary engines. They have the advantage of simplicity and, therefore, low manufacturing costs. They also tend to be more compact than other types of cylinder of the same capacity, which makes them advantageous for use in ships.

Because the piston rod is rigid and the piston itself is long relative to its diameter, the cylinder rocks, or "oscillates" on its trunnion mounting. A pair of holes in the mounting block are arranged so that the rocking motion lines up the holes at the correct times, allowing steam to enter the cylinder in one direction and to escape into the atmosphere or condenser in the other direction.


In full-size engines, the steam and exhaust ports are usually built into the pivot (trunnion) mounting. However, separate valves may be provided, controlled by the oscillating motion. This allows the cutoff timing to be varied to enable expansive working, as in, for example, the engine in the paddle ship PD Krippen. Alternatively, expansive working can also be provided by means of Woolf compounding, just as compactly if the two expansion stages are provided on either side of a single piston within a single cylinder, all arranged as a trunk engine (however, an oscillating cylinder engine does not benefit from the advantage of compactness that a trunk engine would otherwise provide, as it has that already from its own design features). Each approach to expansive working compromises the advantage of simplicity but still retains the advantage of compactness.

If you have an Ender 3, 3D printer this article might be of interest:
The Ender 3 “Clunk”, “Clack”, “Snap”, “Bang” Problem
https://medium.com/@tsbrownie/the-en...m-92b0dde4f998