What sort of engine is this?

[PaulR]

Came cross this vertical version with an eccentric and fixed point linkage to operate the valve. Still thinking about a version of one of these mechanisms for a bar stock engine.


<a href="https://www.youtube.com/watch?v=gxypsHPmZ74" target="_blank">http://www.youtube.com/watch?v=gxypsHPmZ74</a>

[Sanjay F]

Isn't that like/similar to the McOnie's oscillating engine?

<a href="https://www.youtube.com/watch?v=IzxlKeCpupA" target="_blank">http://www.youtube.com/watch?v=IzxlKeCpupA</a>

[paul gough]

Looks like Hornes Oscillator from 1890 or there about. There is one in a museum somewhere and a video on you tube which looks similar to yours but I seem to remember a description of it was displayed giving details, perhaps do a search with keyword ‘Oscillating steam engines’. As I can’t see the valve drive all that well, if there is a curved link in the valve drive it might be a Penn engine. Regards, Paul Gough.

[vtsteam]

Came cross this vertical version with an eccentric and fixed point linkage to operate the valve. Still thinking about a version of one of these mechanisms for a bar stock engine.

That almost looks like a bash valve that the big end is hitting, from here.... but I do see the eccentric...

[paul gough]

Take a look at the ‘Crofton beam engines’ website and go to ‘small engines’. It is in their collection and there is a little information shown, eg 8x18 cylinders, 1870 origin not 1890 as I said in my previous post. Maybe contacting the museum might provide more details than shown. Regards, Paul Gough.

[Jasonb]

Given the sizes that you tend to work in it will be quite a job to get the eccentric and the various pivoted levers of that design all into such a small engine. Even then the slide valve would be tiny and changing to a piston valve equally small if your engine bore is 8-10mm

There are other oscillating cylinder engines with a less complex arrangement of a couple of levers to work the valve, Elmer has one which is not unlike the Digger engine I did a year or so ago or an end pivoting one like the Jekyll. You could do away with the problem of steam in via the trunnions and just have a flexi tube straight to the valve chest which would also simplify things.

<a href="https://www.youtube.com/watch?v=YBbB2WvekKo" target="_blank">http://www.youtube.com/watch?v=YBbB2WvekKo</a>

<a href="https://www.youtube.com/watch?v=hE2lvebyZlk" target="_blank">http://www.youtube.com/watch?v=hE2lvebyZlk</a>

[PaulR]

Take a look at the ‘Crofton beam engines’ website and go to ‘small engines’. It is in their collection and there is a little information shown, eg 8x18 cylinders, 1870 origin not 1890 as I said in my previous post. Maybe contacting the museum might provide more details than shown. Regards, Paul Gough.

Yes that 'Horne' oscillating engine looks like it Paul, second engine in the list here:

https://www.croftonbeamengines.org/engines/small-engines/

[PaulR]

Given the sizes that you tend to work in it will be quite a job to get the eccentric and the various pivoted levers of that design all into such a small engine. Even then the slide valve would be tiny and changing to a piston valve equally small if your engine bore is 8-10mm

There are other oscillating cylinder engines with a less complex arrangement of a couple of levers to work the valve, Elmer has one which is not unlike the Digger engine I did a year or so ago or an end pivoting one like the Jekyll. You could do away with the problem of steam in via the trunnions and just have a flexi tube straight to the valve chest which would also simplify things.

Thanks for the suggestions, I'll think on it a bit longer. I have another idea for a slightly different arrangement but need to sketch it out to see how fanciful it is!

[PaulR]

Isn't that like/similar to the McOnie's oscillating engine?

I can't quite see what's going on there but it must be fairly similar. That said it looks rather complex for my abilities!

[paul gough]

There is another engine that is somewhat similar to the Horne engine and is in the Science museum. A photo can be seen if you enter in the search box ‘Harvey and co oscillating engine’ or just ‘oscillating engines’ and scroll to it. It is also a 1870 engine. This one is a little more involved but is quite handsome. If you want a simpler style but still a historic engine the same place has a drawing of Maudslay’s early oscillator. Regards, Paul Gough.

[PaulR]

There is another engine that is somewhat similar to the Horne engine and is in the Science museum. A photo can be seen if you enter in the search box ‘Harvey and co oscillating engine’ or just ‘oscillating engines’ and scroll to it. It is also a 1870 engine. This one is a little more involved but is quite handsome. If you want a simpler style but still a historic engine the same place has a drawing of Maudslay’s early oscillator. Regards, Paul Gough.

Thanks for this. Simple and a bit different is what interests me. I don't have the skill, equipment or interest to build replicas but I like to adapt mechanisms to suit simple engines.

This is the other idea that's been floating around my head some time time. The piston rod is the the right, the T-shaped cylinder pivots in a 'cradle' with two holes, one for the inlet the other for exhaust, the cylinder has a single hole at the back. Basically it's a wobbler with the pivot near the end and the ports on the back instead of the sides. Actually I suppose it's more like a rotary valve engine.

Crazy idea #2: The cradle could be a complete block with a vertical slot in the front allowing the cylinder to move up and down like a gun turret! That would also remove the need for pivots either side.

[paul gough]

Sounds like you enjoy conceptualising, trying to keep things simple in engineering has been challenging designers forever. In the mechanical 19th century you would have been an “Experimentalist”. Trying to create simple, workable and makable engines is a challenging intellectual endeavour, especially if you are pursuing novel designs. Keep exploring, it is the fountain of youth. Regards, Paul Gough.

[Jasonb]

If you fancy a double acting version of the engine you sketched this may suit.

[crueby]

If you fancy a double acting version of the engine you sketched this may suit.

Thats a very interesting take on an oscillator!
Did a quick search, found this:   https://modelengineeringwebsite.com/Hamers_oscillator.html

[PaulR]

If you fancy a double acting version of the engine you sketched this may suit.

Haha, well there we go, there's nothing new under the sun! I didn't get to thinking about a double acting version as I wasn't sure the single acting idea was remotely sensible