Model engineering is the hobby of constructing machines in miniature. The term was in use by 1888
The 'classic' areas of interest are live steam models (typically steam locomotives, stationary engines and traction engines), internal combustion engines, and clock making. Other popular subjects are Stirling engines, workshop equipment, miniature machine tools and ornamental turning. These constitute stable genres which are often reflected in competition categories at model engineering exhibitions. In the past, amateur electrical experimentation (the precursor to hobby electronics) and ship modelling were considered as part of model engineering, but these are no longer regarded as core genres.
Model engineers typically produce models made in metal. These are machined from stock metal and castings. Some of these are intended as utilitarian working models, others as highly meticulous display models, or sometimes a combination of both. The model engineer usually purchases commercially available drawings which are used as reference to make the models. However some people produce their own drawings, or even work without drawings. The most elaborate models involve hand manufacture of thousands of parts, taking thousands of hours to complete, usually over a number of years or even decades. There are some complete pre-manufactured kits available, but these are limited in the choice of subject matter and are usually expensive.
Model engineering kits These fall into two categories: machined unmachined kits. Unmachined kits usually consist of drawings, castings, stock metal, and possibly fasteneres and other fixings necessary to complete the model. They require machining facilities to complete and often also require additional components and raw materials. Typically the minimum machine requirements are a lathe, drilling machine, and possibly a milling machine. A good level of knowledge about machining is necessary to successfully complete these kits.
Machined kits are a set of parts that are fully machined and only require finishing with hand tools, painting, and assembly. Workshop machinery is not required. The kit will typically contain all the parts necessary to complete the model, including all fixings, pressure gauges and other steam fittings, etc. These kits require a lot less work than an unmachined kit, but are very expensive. Availability tends to be limited as productions runs are small due to the high price.
Building from scratch Many builders do not use any pre-fabricated parts, ready-made castings, or even published drawings. This is called "building from scratch", and it adds another facet to the hobby.