This is my version of this little engine. Made a few variations from the original design by adding micro ball bearings for the crankshaft, the cam follower and conrod big end. The piston was made from graphite. the engine has proven to be a good runner. There is a short video https://www.homemodelenginemachinist.com/media/20181122_101602.1456/ Sorry but don't know how to include the video in this post. This is my first post though I've been lurking for a few years. Found this to be an intriguing engine to build especially after making a mistake in CAD when trying to metricate the plans. Discovered my mistake partway through the machining the engine body thereafter many parts had to be made on the fly to accommodate the first error.
