The late Bob Jorgensen of Memphis made a working model of the Robertson, but I didn't know that was the name of it. I only wondered what sort of an idiot would have designed an engine like that and how the pistons were sealed. It is nothing like a Dake which Bob also built as the Dake was flat and very compact. Disregarding that the Robertson must have been a complete idiot, the Ascot model is a beautiful work of art and the modeler should be proud of what he has made. Being rather odd myself, I like the design. Jesse in 40° drizzly Troy, TN USA Subject: [modeleng] Re: Square pistons There is a photo of one, taken at Ascot, at: http://www.flickr.com/photos/13181394@N03/1382882848/ Alan MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.