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Jerry Ginn,      

This is a wobble plate engine of my own design called the "Weeble", (weebles wobble but they don't fall down).  There are four axial cylinders with bore 17/32" and stroke of 17/32" for total displacement of .471 cid.

Air or steam is admitted to each cylinder through a rotary valve incorporated in the output shaft.  The linear motion of the pistons is converted to rotary motion by the wobble plate or 4 armed spider.  This engine was first run in early December 2008 after a 2 month "Idea, design, build" cycle.  It runs quite smoothly and throttles easily from about 60 RPM to several hundred RPM (I don't have a tachometer) on less than 20 PSI.  Although the video shows a 2" diameter flywheel, the engine runs very well with no flywheel.  The shaft has been left long while I try to decide what kind of load it will drive.

The critical design/build element are the ball joint connections at the ends of the spider arms and the ball pivots at the plate center and the crank web.  These are 3/16" stainless steel balls running in brass sockets.  My search of the FAME site returns no hits on the word "wobble" or "swash" so I guess that this is and unfamiliar type here, but its main advantages are compact size, low part count, and economical construction.  This one contains less that $15 in materials.

Here are some pics attached and links to youtube videos.


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