# So you wanna play Guess huh???



## 4R8 (Nov 15, 2011)

pm sent
:biggrin:


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## Tony Wells (Nov 15, 2011)

Comes with its own supply of grease,  I believe.


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## Old Iron (Nov 16, 2011)

Old Style rotary Airplane engine:thinking:


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## Tony Wells (Nov 16, 2011)

No, it has only seven moving parts.


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## 4R8 (Nov 16, 2011)

I did believe this thing was a myth when i was told about it.

Hopefully Bill can give a rundown on how they work after


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## Tony Wells (Nov 16, 2011)

It is said that they are difficult to build, and not for a budding engine builder. I can see why. Pretty cool design though,


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## 4R8 (Nov 16, 2011)

Ok, after reading the article for a second time and thinking for a while, I finally believe i understand the process in which these work.

I'd only heard about these in a riddle years ago like yours for the same reason, less moving parts then there is pistons.

What i can come up with is air/steam enters the ports on the drum and crank at a set point. Probably at a point where the piston pair receiving the pressure is at or just past the base of it's stroke (the article mentions 90 degrees of rotation, could't each one give nearly 180 deg?) . Once the piston pair reaches it's longest point (top of the crank and furthest from crank on the drum) the pressure is released. 

Another thought was in the design you could have the pistons either hollow or solid. It would probably work either way with no measurable difference. 
Although a hollow piston may not be quite as efficient due to the larger volume which would need to be compressed and released?

I want to see one run. Unfortunately, using works remote area satellite communication system means youtube is out (along with most pics on the forum too ) I'll have to wait.

Jason


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## Tony Wells (Nov 16, 2011)

Bill, I didn't mean to sound discouraging to anyone. I don't thing they are super difficult, but I have seen some drawings, and it would be challenging for the less experienced. In order to get the engine to run, things have to be very perpendicular, and closely held to size. Not impossible, but not much room for error.


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## ScrapMetal (Nov 17, 2011)

Bill,

Thanks for saying where you got the plans.  I looked it up on Google Books: http://books.google.com/books?id=P-...page&q=popular mechanics elbow engine&f=false (starts on page 166)

Looks like a neat little engine, good article too.  While I was reading through it I also found an interesting article on "Lathe Inlaying". (page 170)  Both articles are worth reading.

-Ron


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## 4R8 (Nov 17, 2011)

Bill Gruby said:


> 4R8 -- The hollow piston would give you mucho trouble. The air to run this engine pushes from the bottom.
> 
> "Bill Gruby"  :thumbzup:



The air is fed from the base _and _the crank drum, giving the 10 pistons from 5 pieces. 
I still believe a hollow piston set would work. Then you would only need the one inlet and exhaust port instead of the two entries.


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## 4R8 (Nov 17, 2011)

Ah, when one end is taking in air the other is doing the same thing. When one end is moving upwards, the other end is moving outwards.


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## 4R8 (Nov 17, 2011)

yep, and shows both ends of the piston doing the same task. :biggrin:


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