Hi,
Yesterday a model engine for repair arrived from a friend; it has an issue with its crankshaft. It is an interesting design anyone have any ideas about the model (which is very well made) or a possible prototype?
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Take care Tony.
Hello again,
The engine just needed adjusting. It is the first time I have worked on this type of engine. A lot of work to balance reciprocating mass?
https://youtu.be/wl0UABm18_0Take care stay safe.
Tony.
Hi, Tony,
Maybe it's my lack of brain power these days, but I see only one piston there, with a dual connecting rod thing attached to the crosshead. Those two rods run off identically timed crankshaft throws, and I guess are necessitated by the design of the frame. Neat.
But am I wrong? Is there another piston and valve assembly lurking somewhere beyond the range of my failing vision?
There are two connecting rods attached to each other at the top.
Hi Bob,
There are two pistons at 180 degrees to one another in the same cylinder and the two cross heads share the same guides; the centre crank drives the lower cross head its piston rod going through the piston rod of the upper piston rod which is driven by the two outer cranks. The lower cross heads piston is at the top of the cylinder the higher cross heads at the bottom. The pistons start together in the middle of the cylinder which is twice the length of the stroke and they move apart. I hope this makes sense? The idea I think is to have a balanced engine.
Take care Tony.
Ah, now I see (said the blind carpenter, as he picked up his hammer and saw)!
It was very hard for me to tell from the video, I guess, but as soon as I cottoned on to that hollow piston rod things became much clearer.
Great engine, Tony. You should keep it and tell the guy it got lost.😏😏
That's a great find, Tony...!!!
Very well done!
Gil
I've seen that single cylinder, opposed piston concept used in old gas engines before, running on natural gas if I recall correctly, but this is the first time I've seen it done in a steam engine, that I can remember.
Nice engine, with a unique and complex engineering design, very well executed!
I'm sure you will work your magic on that Tony!
Could be a commercial design but it is hard to tell, it could well be a prototype. Regardless it is a very interesting design!!
What an interesting engine that is Tony.
Thanks for posting the video Tony and nice work on getting it running again.
I had not seen this design previously.
And I was surprised no other Forum Members had any information on it.