This is drawing #506 of the engine. The steps were: 6 mo analysis of robot to get the proper engine output specs, then 6 mo thermodynamics analysis to work out the size and number of the cylinders of the engine that should (predicted) maximize efficiency and minimize noise output of the engine, then 5 mo to figure out how to make the gas control valve (there’s a trick to adding complex solids and it took me forever to understand how to do it), then 5 mo to create an engine that shows all this in a manner where people could “see it”. The high quality KeyShot renders take 5 min per image and there are 36 images per camera view. It takes about an hour to put the images together and get it uploaded to YouTube (per video) unless I add voice over, which takes me forever because I’m not that good at voice over.