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Robert FilipiakAlpena MI             3/29//2008

Steam Engine with Stephenson reverse gear

Built in 2005, from plans found on the internet, this is a verticle steam engine with Stephenson reverse gear. Unlike the engine in the plans, this one was built without castings.

It has a 1-1/4" cylinder bore and 1" piston stroke. With 75 or 80 lbs. of steam the engine will run at 1,500 r.p.m. I have not run the engine using steam but it runs nicely on compressed air.



The base for the engine was fabricated from eight pieces of metal welded together.The crosshead guide was made from a piece of 3/4" pipe and 1/8" bar stock.


The cylinder and steam chest mount before being soldered together.


Engine base milled to accept bearing blocks. Note pin in bottom of slot to keep bearing in place.



Bearing blocks set in place. Each bearing is two halves soldered together, mounted in base, drilled and reamed to assure alignment. The halves were then heated to separate, excess solder was wiped off while still hot, then the surfaces were polished with crocus cloth.Paper shims were added between halves to allow for shaft clearance. They can be removed when bearings wear. 



Crankshaft ready to be fitted.


Eccentrics for Stephenson Reversing Gear.


Cylinder ready to accept steamchest.


Flywheel and tapered bushing. I opted for this arrangement rather than the keyway and setscrew. Besides, I just had to make one! Bolts are made from annealed allen wrenches.


Reversing gear pieces.

Crankshaft and connecting rod trial fit. The plans called for oil cups, I thought oil bottles looked better.The holes in the tops are for adding oil using a syringe.The bottles are 1/4" O.D. with 4-40 thread

Assembly complete. The plans called for sheet metal lagging but I chose wood lagging instead. I thought it would enhance the look of the engine.



Notice the offset in the eccentric linkage? That was probably the hardest part to make. The more you bend it, the shorter it gets!




Copyright 2008,  Florida Association of Model Engineers and engine builder as noted above, All rights reserved.