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For my first serious attempt at metal turning I decided to design and make a little steam/compressed air engine. Although the principle of rotating the piston to get the necessary port timing is not new I have not seen anyone do it the way I did!

Concept:


Some of the components:



The 'nutating' big end bearing



Milling the side frames in my lathe



The crank shaft is assembled, I took the easy way and used adhesives.



All the bits together in one place



Marking the position of the exhaust port, I put the felt pen in the cylinder port and turned the engine through one revolution.



The cylinder was drawn aside and this is the shape that appeared on the piston sleeve.


Just before final assembly, the row of exhaust ports drilled in the piston sleeve and the cylinder port visible in the cylinder. The inlet port is at the bottom of the cylinder and has been drilled in the same manner but obviously covering the other half of the cycle.



Sorry but my camera froze the action so you will just have to take my word for it that here it is running!

John, that is fascinating, it would be great if you could post a video of it in action

Not just fascinating but oddly exciting too! https://www.youtube.com/watch?v=S5QErPDNcj4

I assume this sort of thing takes place in the Secret Room?

Chuks wrote:Not just fascinating but oddly exciting too! https://www.youtube.com/watch?v=S5QErPDNcj4

I assume this sort of thing takes place in the Secret Room?

JG Ballard/David Cronenberg eat your heart out...

See the breaking glass
In the underpass
See the breaking glass
In the underpass
Warm leatherette

Hear the crushing steel
Feel the steering wheel
Hear the crushing steel
Feel the steering wheel

Warm leatherette

Warm leatherette

Warm leatherette
Melts on your burning flesh
You can see your reflection
In the luminescent dash

Warm leatherette

A tear of petrol
Is in your eye
The hand brake
Penetrates your thigh
Quick - Let's make love
Before you die

On warm leatherette
Warm leatherette

Warm leatherette
Warm leatherette
Warm leatherette

Join the car crash set

I have never been able to look at a light twin wing in the same way ever again...

[bbvideo=560,315]https://www.youtube.com/watch?v=iSsYUAKGQs4[/bbvideo]

MB

Thanks Probes...

Very impressive John.

Wish I had skills to be able to make things like that.

Very skillful to be able to make something like that. Wish I had the touch with metalwork to do something half as good.

The potential for that device has the mind turning to evil thoughts.

Hydromet wrote: Wish I had the touch with metalwork to do something half as good.

It is not at all difficult and this is very minor stuff, the hardest part of getting this far was buying the equipment. If you have the inclination there are plenty of very experienced metal workers online who will guide you in your first steps.

It has been a lifelong project of mine to have my big end nutated (preferably by a girl that looks like the blond woman in the Cronenberg film Crash) but as I get older this seems more difficult than I had hitherto found the task. I guess as we are talking about nutation I should say that is the way that life precesses...

In days of yore, in a dark place, in the land of Voldemort, I would have been immediately banned with some rude attempt at sarcasm by Voldemort of one of his minions for the insouciance noted in my post. Here, hopefully, I will just be left to grow up, be British and say that John Hill seems to be a good craftsman whose skill has afforded me an opportunity at some childish humour whilst also introducing me to a most interesting, nay fiendish, piece of engineering. For this I am thankful.

Caco

Caco, just imagine what could be in the "secret room".

Dushan wrote:Caco, just imagine what could be in the "secret room".

It nutates (oops I meant boggles) the mind Dushan!

Caco

John, that is absolutely fascinating and quite mind-boggling, beats sleeve valves stone cold dead.

If you are into doing more air engines I have a similar project thought of but never made. It would require six cylinders, three small and three large. You can see where I'm coming from if I describe it as a fixed displacement Brayton cycle engine. Interested?

That would be very interesting Henry.

As you can imagine the somewhat unusual characteristic of the nutating big end engine is that port openings on the up stroke may be quite different to the openings on the down stroke and would appear to have the potential for development of 2 stroke engines. A practical challenge though is how to arrange the sealing between the piston sleeve and the ports in the outer casing in my little engine I just waste air!

This is the general principle. I think the expander piston has to be larger than the compressor. Or suitably geared. To smooth the flow either three cylinders for compressor and three for expander, or a large reservoir/accumulator.

Ho boy! I have so many ideas for projects in the pipeline already but that looks very tempting!

Fascinating project, nice work.

I now have to Google Brayton cycle engine!