1/5th Scale Denny Improved Ericsson

Jasonb · Sep 18, 2024

Another notch on the workshop wall, this time a 1/5th scale model of a Denny Improved Ericsson hot air pumping engine. I drew it up from the original patent drawings and images of full size ones found on the net. The bre is 40mm and the flywheel 145mm dia. There is a mix of steel fabrications and parts cut from solid, no castings were used although I did cut the flywheel from a slice of 150mm dia cast iron bar.

There is a small camping gas stove's burner mounted at the bottom of the furnace which provides the heat source

It's knocking a bit as I removed the pump's piston so I could blow air into it for cooling therfore the rod is not being guided that smoothly but otherwise not running too badly.

GreenTwin · Sep 18, 2024

Jason-
Really nice build, and great color scheme.

I highly encourage the model engine folks to learn the method JasonB uses, ie: find old patent drawings, photos of original engines, etc., create an accurate 3D model, and then build an engine.
Putting the design into a 3D model gives a lot of options, such as CNC'ing parts or patterns, and 3D printing patterns to allow castings to be made.

I like the entire approach, and I think it is the way of the future.
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Jasonb · Sep 18, 2024

Thanks Pat, the pumpkin orange seems to be the works colour, some had the flywheel in the same orange others with the dull red. I was tempted to do another distressed paint job on this one like I did with the Heinrici but in the end just add a coat of clear matt over the colours as I felt the gloss was a bit too flashy.

Yes CAD and in particular 3D CAD seems to be the gateway to all the modern tech which you need a reasonable grasp of if you are to make use of it all.