I have had a frustrating but reasonably constructive few days dreaming things steam bike. I had an hour of FreeCAD crashes whilst constructing a piston valve. I blame myself as I’d filleted and chamfered everything, there was just too much mesh in the job. I was gathering myself together when I realised the bloody engine I was contemplating would be over two feet long when the cross-slide and crank were included. I did consider an over square engine but then thought of using a car air conditioner pump as a steam engine. These pumps are a multi cylinder swash plate set up and are very compact a