In August 2010 I saw an engine on the Preston Services site which I really liked (image 1) and wanted to build. Many of you may remember it. I copied the 4 images that Preston provided, and with the data in the advert (12 inch flywheel, approx 2 x 5 bore x stroke) I proceeded to create a (very bad) 3d model of the engine at 50%- a size which would fit my equipment well.
Fortunately friend Pat down in Memphis, who is a wizard with Solidworks, took pity on me and redrew the engine. A rendering of that model is shown as image 2 below.
I had originally wanted to do a barstock version of the engine, but Pat persuaded me that it really should be cast and volunteered to produce the castings.
At that time I was a member of a local makerspace which had a 3d printer, and I used it to produce the basis for patterns of the small parts (image 3) as well as the bosses for the base, suitably scaled and with draft added. I had difficulty getting a flywheel printed as the printer kept failing late in the prints (costing me money), so I located a firm in Knoxville near Pat which produced a beautiful set of flywheel patterns and delivered them directly to Pat.
By this time (we're in 2012 now), Pat had acquired a 3d printer and using it created the basis for a cylinder pattern. A good deal of hand work was necessary to get the 3d patterns to work properly.
Pat built a foundry and went through a number of furnace designs and numerous iterations of molding strategies (foundry work has a long learning curve), but eventually (late 2015) there were castings in our respective workshops.
A few months later and we have the engine you see in the photos (images 3,4). It runs, and while there are fasteners to replace and some fine tuning to do, I'm calling it basically done and I'm going to just look at it for a while.
Pat's engine is not yet finished, but he has run it with one cylinder - and his is green.... (last image)
Don't you love it when a plan comes together....
Pat has documented his build and plans to publish details of the build with the drawings in a magazine article. There are no plans to make castings available.
I deleted the sound from the video because of the compressor noise.