Welcome Bejo, glad to have you here.
My dad retired in the 1990's (I forget the exact year), opened a machine shop, did machining work for a while, sold his machine shop, and then put a small shop behind his house.
He proceeded to make a lot of model steam engines, two Roper replica steam bikes, and a Stanley replica steam auto.
Dad worked in a vacuum with a level of secrecy that Fort Knox would admire, and so I had little access to what he was doing, or how he was doing it during those years.
Dad would make a few sketches on vellum (commercial cotton drafting paper), work out the geometry, and in short order have a working engine running on the table.
For the Roper replica steam bikes that dad built; while they did function, since there were no steam calculations made, then the bikes tended to run out of steam during a ride, at which point one would have to stop and let the pressure build up again. The fuel he used was charcoal.
Looking back on the Roper replicas, and studying successful steam designs like the Stanley steam auto, I think what the Roper needed was a pressurized white gas fuel system with an adjustable burner, so that the steam pressure could be modulated in accordance with demand.
Dad's Ropers were ridable, but with little power.
Engine was a single cylinder design, probably with no consideration given to cutoff.
Dad's Roper's did draw a lot of attention at the local engine shows, and I think for dad, that was what it was about, not so much making a well designed and fully functional steam bike.
Here are some Roper replica photos, and a few other things dad built.
All barstock construction; no castings.
I have a video somewhere.
Nice bike you have there !
I think a two-cylinder compound would save on boiler size/capacity, but would be a more complex engine, and perhaps not as functional on a bike as single expansion.
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