My second model with a beam is an engine known as “Grasshopper Beam Engine”. Perhaps this name becomes more understandable if you watch it running.
Here is a video from a test run - it’s really pumping !
The model features three characteristics:
- Evan’s linkage [a nice animation may be seen here]
- Many parts made from wood
An article of A. Bachmann in “Maschinen im Modellbau” 1993 and the corresponding VTH construction plan “Einfache Grashüpfermaschine” were the starting point of the model 1. The given sizes did not fit my machinery. So I scaled down the model to approx. 70 %. Furthermore I built a normal double action type engine and not the uniflow engine described in the plan (first patents in 1903, so unsuitable for a beam engine).
The model’s flywheel is made of distinct parts. This technique was used to avoid problems casting such big parts as well as handling them e.g. during shipping.
This model is suited well for a beginner. The american model engineer Elmer Verburg has made plans for such engines, which may be downloaded here (not metric).