SignalFailure
Well-Known Member
- Joined
- Jan 1, 2008
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Here's my latest project, now nearing completion.
It's a hot air engine which essentially works in the same way as the current 'engine of the month'. The original design made from tins, wood and goodness knows what was first published in the early 1900's and subsequently 're-worked' by Edgar Westbury in the 1940's as a 'proper' model engineering project. No exact dimensions, construction methods or materials were given as Westbury suggested the design could be adapted to suit whatever was to hand in the workshop (bits of this and bits of that, hence the name, although I call my engine 'Archie' after the original author). When someone gave me some lengths of 2 and 2.5 inch brass tube earlier this year I knew exactly what I'd use them for!
The upper tube has a water jacket supplied with cold water via the two threaded in/outlets on the left-hand side and below that is the displacer chamber. The upper tube extends about 1/2" inside the lower and sits on a copper 'hot plate'. The displacer is a cylindrical 'box' and it's movement is controlled via the eccentric.
Materials used are brass for the tubes, little end, eccentric rod, cylinder bracket, bearings, cylinder seat etc and cast iron for the cylinder, piston and eccentric. The hot plate and tube flanges are made from copper. The flywheel is a lump of cast iron 'hollowed out' each side but not yet finished (it had such a tough skin it alsmost killed my poor mini-lathe!). The psiton rod and eccentric cheeks are mild steel and the crankshaft is silver steel.
There are a lot of temporary fasteners in the photo (witness the huge screws in the eccentric cheek plates, firebox flanges and eccentric rod!) and the angle/macro makes some of the angles look a little wierd (the cylinder is parallel to the main tube, honest!)
The firebox and main tube curves were filed by hand using paper templates stuck on with 'pritt stick'. The hot bits are all siver soldered, the cold bits are soft soldered. The power cyliner bore is about 3/4" and the stroke a little less than an inch.
It's not up to the mega-accuracy machining that most engines on this forum display as I had to make it up as I went along and don't have any sophisticated gear but it seems to have the smoothest motion I've yet managed to create so I'm hoping that it will be a runner.
I've taken a fair few construction pictures if anyone is interested.
It's a hot air engine which essentially works in the same way as the current 'engine of the month'. The original design made from tins, wood and goodness knows what was first published in the early 1900's and subsequently 're-worked' by Edgar Westbury in the 1940's as a 'proper' model engineering project. No exact dimensions, construction methods or materials were given as Westbury suggested the design could be adapted to suit whatever was to hand in the workshop (bits of this and bits of that, hence the name, although I call my engine 'Archie' after the original author). When someone gave me some lengths of 2 and 2.5 inch brass tube earlier this year I knew exactly what I'd use them for!
The upper tube has a water jacket supplied with cold water via the two threaded in/outlets on the left-hand side and below that is the displacer chamber. The upper tube extends about 1/2" inside the lower and sits on a copper 'hot plate'. The displacer is a cylindrical 'box' and it's movement is controlled via the eccentric.
Materials used are brass for the tubes, little end, eccentric rod, cylinder bracket, bearings, cylinder seat etc and cast iron for the cylinder, piston and eccentric. The hot plate and tube flanges are made from copper. The flywheel is a lump of cast iron 'hollowed out' each side but not yet finished (it had such a tough skin it alsmost killed my poor mini-lathe!). The psiton rod and eccentric cheeks are mild steel and the crankshaft is silver steel.
There are a lot of temporary fasteners in the photo (witness the huge screws in the eccentric cheek plates, firebox flanges and eccentric rod!) and the angle/macro makes some of the angles look a little wierd (the cylinder is parallel to the main tube, honest!)
The firebox and main tube curves were filed by hand using paper templates stuck on with 'pritt stick'. The hot bits are all siver soldered, the cold bits are soft soldered. The power cyliner bore is about 3/4" and the stroke a little less than an inch.
It's not up to the mega-accuracy machining that most engines on this forum display as I had to make it up as I went along and don't have any sophisticated gear but it seems to have the smoothest motion I've yet managed to create so I'm hoping that it will be a runner.
I've taken a fair few construction pictures if anyone is interested.
