This guide is a short edited extract from MAINSTEAM MODELS "The Complete guide to Miniature Steam" which is now available via my website, on CDROM or Internet download. It is written with the beginner in mind and covers many essential principles for sucessful running of miniature steam engines, locomotives, traction engines & steam boats.
There are many types of model steam engines, all suitable for different applications. My advice is to be very careful & think before you buy! The small Mamod and Wilesco range of both stationary, rail & traction engine/steam rollers etc are good to watch & good fun to play with.
Usually, a bent crankshaft & severe wear on the main bearings are but one of the problems with old steam engines, always ask the seller what the condition of the main bearings is like regarding "play" or "slop". If you are not careful, you could end up with an engine that is just worn out everywhere & really needs a full rebuild. There is no fun at all in watching an old, badly made, worn out steam engine knocking away & struggling to run, owing to bad valve timing, ill fitting pistons etc etc. Believe me, I have seen many worn out and/or badly made engines, I have rebuilt a few over the years. Sometimes it is better to start & just make a new one!
If the steam engine that you have your eye on is an Ebay item, look for the obvious tell-tale marks of pliers on shafts, screw heads chewed up by rough usage, odd nuts & bolts, missing nuts & bolts (this can indicate sheared off studs, difficult to rectify on small engines) localised oil staining & white residue on the metal parts of the engine can be a good guide to the condition of the seals & gaskets. Always email the seller before bidding, for information of the wear & tear on the engine. You should be able to gather information as to whether the seller is a genuine steam enthusiast, or someone who is just selling an item on to make a quick profit. The price you pay should be dependent on your model engineering skills to a certain degree, If you have a lathe & know how to use it, remanufacture of an old steam engine is usually quite straightforward, albeit a pain sometimes. If you have little or no mechanical skills & experience, then you could be disappointed if the engine that you buy is falling to pieces or very badly made.
A final note:
On high pressure model steam engines, it is necessary for all the live steam pipework to be silver soldered. As the boiler & steam temperature rises sharply with the increase in steam pressure, even wet steam at 80 psi can melt soft solder with unfortunate results. Even without a superheater, (where the steam feed to the engine passes back through the fire) the temperature of live steam pipework can very quickly burn your fingers.
I hope that this guide helps you buy the right steam model for your needs,
This is an edited version taken from "The Complete Guide to Miniature Steam"
which is now available on CD-ROM or Internet download. The explanations are much more detailed within the CD-ROM guide, which also contains illustrations & photo diagrams. There are many useful references to model live steam in general especially steamboats.
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