The Simpson and Shipton Short Stroke Engine

[SteamR]

During a certain period I was fascinated by steam engine designs which are from today’s perspective a bid strange. Anthony Mount has a great feeling for such old-fashioned designs, so he developed a considerable number of model engines from the early days of the steam era. Over the years I build a few models of this field of interest.

The Simpson and Shipton Short Stroke Engine is a more complicated steam engine model. The prototype of the original was presented in 1851 in the Great Exhibition in London. It was indented to power a textile machine.

The drawings based on the patent were developed by Anthony Mount. The castings are purchased from pollymodelengineering: https://www.pollymodelengineering.co.uk/sections/stationary-engines/anthony-mount-models/simpon-Shiptons-Short-Stroke-Engine.asp

The design principle is a rotary steam engine nevertheless in a curious way using the principle of the typical reciprocating engine. The piston is arranged horizontal and rotates during the stroke. The piston axle is eccentrically arranged and moves during a rotation in a circular arc track back and forth. The piston axle remains more or less on the same vertical position. The reciprocating movement of the piston is realized via the rotation of the piston in connection with the eccentric axle.
For explaining the internal design and movement of the piston I have a simple brass steam engine model (a model for the model). This model was an early failed attempt based on the book “Steam and Stirling – Engines you can build”, but now very useful to explain the engine.

Looking on the cylinder casing from top view the cylinder bore has the shape of a square channel.
There are four connecting rods, two of them for guiding piston axle on the circular arc track. The remaining connecting rods transfer the rotation to the crankshaft. The connecting rods are connected via old fashioned hangers and wedges.
By design the engine has no seals applicable, like piston rings. This makes the commissioning of the engine very difficult, one have to find the point between no rotation caused by blocking and the other extreme too much leakage.

Technical Data:
Stroke:     42mm
Piston diameter:        43mm

On this website you can find a very informative animation: http://www.museum.alibaba.sk/MUSEUM/POWER/rotaryengines/rotaryeng3.htm

[Admiral_dk]

Very nice build  + you made the effort to make it look as it could have been installed in some Engine House 

I couldn't decide if I had seen one here on site before - so I used the search function (and there are a few hits), but the first one is eleven years ago : https://www.modelenginemaker.com/index.php/topic,31.msg106.html#msg106

Per 

[Kim]

Those are some very interesting steam engines!  Nicely done too!   

Kim