Geometric Modeling and Digital Restitution of a Two-Cylinder Vertical Compound Steam Engine with Speed Control by Henry Muncaster

This paper shows the result of the process followed in the geometric modeling and digital restitution of a two-cylinder vertical compound steam engine with speed control designed by Henry Muncaster and published in the ‘Model Engineer’ journal in 1957, as a step prior to explaining the operation of said invention. For this, the Autodesk Inventor Professional 2023 software has been used in order to obtain its geometric modeling and virtual recreation, as well as AutoCAD Mechanical 2023 to obtain its graphic documentation from the available plans. However, during this process it has been necessary to make a series of hypotheses about the geometries of some elements, estimating their dimensions and applying a series of dimensional, geometric and movement (degrees of freedom) constraints, in order for the 3D CAD model of the invention to be coherent and functional. On the other hand, one of the drawbacks detected with the use of the Autodesk Inventor Professional software arose when assembling the invention, since this software does not take into account the deformation of components made up of elastomeric materials such as the movement transmission belt. After the 3D CAD model had been generated, and taking into account the error caused in the assembly by the geometric constraints of the transmission belt, the graphic documentation of the invention (assembly plans, exploded view and dimensioned plans of each element according to the standards) was obtained. Finally, the simulation of the operation of the invention was then carried out, obtaining a virtual recreation of the steam engine.