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Thats a clever way to do it! Looking good.What is the purpose of the air pump in the engine?Ok the "Air pump" is used to drain the "condenser" (bit of pipe below the engine where the exhaust steam goes) of the water that is squirted into the exhaust steam to cause a vacuum to help the engine be more efficient. this water that accumulates has to be got rid of, so, there is a water pump that pulls it up out of the way and sends it to the boiler via another pump that is connected by a shaft on the other side of the beam. Sometime in the past someone has decided to call this the Air Pump as it does have some air in it. some pics of the arraignment.......
Interesting to see that even the builders of the real thing had the occasional "whoops" moment!I think the reason for the beam needing this quick fix is that it was possibly an already made pattern that was not meant to be used with an air pump rod. To get perfect parallel motion the centres of the crossheads have to be in a straight line drawn from the centre of the beam bearing to the bottom centre of the beam end crosshead. that is why the HP strap has the piston rod crosshead slightly higher that the coupling rod link. The HP and the LP links are to be made next then the engine is basically finished apart from the condenser and air pump.
Saw this paragraph from an 1872 book about steam.................................!!!
Quote from: steam guy willy on February 13, 2017, 03:54:53 PMSaw this paragraph from an 1872 book about steam.................................!!!Well, I'M not going to test it! I shan't either ,,,,,,,,,,!!I am now making the LP strap , this is quite a complicated looking part and i shall explain it bit by bit. this drawing was made over 2 years ago so i have had sometime to work out how to do it. I have started with a piece of 1" x 1" x1/8" angle it has been marked out and two holes drilled at each end. The slot is then milled out and the bottom hole is filed square to allow the brass bearing to be filed to fit the aperture and then slid up to the top of the strap and the curves filed to fit The angle is then milled to thickness and............more later.........