# Double-Acting Twin-Beam Engine done



## crueby (Apr 4, 2014)

Just finished this one - a double-acting twin-beam engine. The cylinders are 1" diameter, 2" stroke, and have a standard slide valve. The main beams ate 12" long, and are suspended by a single central post. It runs nice and slow on just a couple pounds of air (the guage on my regulator is just above 0 with it just ticking over, not sure what pressure it really runs down to). There is a needle valve to control the flow so I can leave the air tank at a higher setting and control it at the engine.

Here are a couple shots of it:







And a shot of it next to its little brother, a mini double acting beam engine that I built a couple months ago:



Here is a video of it in action. There is a slight sticky point at the top of the right hand piston that is causing it to hitch a little, but that is running in and going away. Just have to sit and watch it run some more! 
[ame]http://www.youtube.com/watch?v=pYgt7npWCMM[/ame]

There is a build thread for this engine over in the Work In Progress forum:
http://www.homemodelenginemachinist.com/f31/double-acting-twin-beam-engine-build-22713/


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## aonemarine (Apr 5, 2014)

Ok I admit it, im an addict.. i have watched the video five times now and want to watch it a few more.. Is there a cure that doesnt involve walking barefoot through a pile of ss swarf?


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## ShopShoe (Apr 5, 2014)

crueby,

Outstanding. Lots of moving parts to watch. I could see this driving Brian R's. marble machine.

Like the sound, too. I like engines like this running slow over manycylinder models high-revving. 

Thanks for a great post and build log.

--ShopShoe


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## cwelkie (Apr 5, 2014)

Absolutely gorgeous!  Beautifully executed piece of fine machinery done to the last detail.
Thanks for sharing.


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## BaronJ (Apr 5, 2014)

Hi Cruby,
I must add my congratulations !  That is an impressive engine.


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## crueby (Apr 5, 2014)

aonemarine said:


> Ok I admit it, im an addict.. i have watched the video five times now and want to watch it a few more.. Is there a cure that doesnt involve walking barefoot through a pile of ss swarf?



Dunno - I am still watching it myself...! ;D

I recently saw a picture of a beam engine driving a large orrery.... That could be a really fun build! I was hoping this one would run well slow, that is why I picked a large bore, long stroke, plus the needle valve, which lets me rhun a higher pressure but keep the flow down - seems to be a great combination.


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## aonemarine (Apr 5, 2014)

Im up over ten times now LOL,  I just can just picture that engine (scaled up a bit) in my 9' whitehall coupled up to a couple paddlewheels...


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## mirek111 (Apr 5, 2014)

Very impressive !


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## crueby (Apr 5, 2014)

aonemarine said:


> Im up over ten times now LOL,  I just can just picture that engine (scaled up a bit) in my 9' whitehall coupled up to a couple paddlewheels...



Great idea! My first boat was a whitehall i got in Maine. Then I learned boatbuilding and started a whole new hobby. Some friends of mine want me to put it in my kayak, but I think the boiler flame under the hatch might be an issue!


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## OrangeAlpine (Apr 7, 2014)

Love the layout, it allows a gearhead (especially a newly minted one) to see all the "action".

Bill


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## Lesmo (Apr 12, 2014)

Hi Crueby

that's an interesting, and beautifully made engine. Love engines that tick over slowly, and have a lot of moving parts. Mesmerizing

Les


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## nemoc (Apr 19, 2014)

What an elegant engine, I could watch it for hours.


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## ChooChooMike (Apr 25, 2014)

Just mesmerizing to watch and beautifully machined!:bow:

Mike


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