Jekyll’s “Pendulous” Engine c 1870

[JasonBModerator @jasonb]

I first became aware of this engine about six years ago when it appeared along with some others in a Bonham’s Auction and filled the image and description away in my “Future Projects” folder on the PC. It seems quite a few others like it as the image crops up quite often on sites like Pinterest but I have not seen anyone else have a go at making one.

The original was a fairly large model and I settled on a scale of about 4/10ths based on using a piece of 203mm thick wall tube to make the flywheel rim from which gave me a bore of 16mm and stroke of 48mm. Armed with these numbers I set to and drew it out in Alibre. It took a while to arrive at the right pivot point and length of the valve links to get the slide valve to move correctly on the 3D simulation hopefully it will do the same on the physical model. There are a few areas that I have done a bit differently such as the valve chest but the finished model should be reasonably close to Jekyll’s original.

I have not taken photos of all the work but will show the main fabrications and more interesting bits.

I decided to make a start on the two arched column supports. The actual arch part was made by turning down some more thick walled steel tube to the correct inner and outer diameters and then milling away what was not needed before parting the 4 pieces off.

The remaining parts were cut from flat and square bar, I left the feet as one long piece of bar which allowed a bolt to go through the middle with a suitable spacer to hold the square part central and at the correct height for silver soldering.

The two “castings” after a dip in the pickle

The waste material was then sawn out and the cuts edges milled to final size. The counterbored hole will take a cap head screw to attach the column. The tops will be skimmed to final height once the base plate is made and they can be screwed to it in exact position.

[Michael GilliganParticipant @michaelgilligan61133]

A delightful name, Jason

… hopefully the rest of your images will appear soon, so we will understand why so-called.

 

MichaelG.

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Edit: __ and as soon as I posted  that ^^^, they appeared !!

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