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Oh, George, when im already having such an old hand with those Pumps reading my thread:How do you fix the water pump body to the cast iron base? The Stuart plans just "forget" about and I haven't seen any hints on how it was intended.Am I just blind...?Also on the internet, i wasn't able to find any hints.
No nay sayers Jerry....just a polite discussion of the attributes involved. The way is should be.Dave
Quote from: K.B.C on November 18, 2013, 12:55:45 AMI have great reservations that your pump will not work.Hi GeorgeWell, there could theoretically be a case where all the ports are closed. But the probability is very small because the auxiliary valve will have to get over the point where the ports are equally closed until the shuttle valve is going to move.To describe it with an analogy: It is like having a pendulum stopping with the mass above the bearing point. It is possible because of friction but the probability is very small and the stability at this state is very low. Here is a scheme for the principle of my pump:If you look at it carefully you will find out that it wouldn't work that way, the piston would drive the auxiliary valve to the wrong direction. But I have drawn the ports this way to make it clearer when looking at it. If it should happen, that I am really gonna have problems, I will see what I can do. Greetings Florian
I have great reservations that your pump will not work.
FlorianI'm with you on this one. Your modification does not change the way that the valve works. It only replaces two piston valves with two slide valves and I think your reasoning for that is valid and also interesting. Your doubters seem to forget that steam is supplied to the piston by the shuttle valve, which is not directly linked to the eccentric but is more of and either/or device controlled by the primary valve and as you state, is highly unlikely to come to rest between states. If you have any problems getting regular cycling, i would bet that fine tuning the primary valve will resolve them.Jerry
In your drawing it shows the piston in mid stroke and the Shuttle valve covering both ports, is this a small mistake, if not how does the steam get into the L/H. side to blow the piston to the bottom and as the shuttle is hard against the R/H side how are you to move it to get steam behind the piston to blow it to the top. ?
Quote from: K.B.C on November 18, 2013, 09:31:44 PMIn your drawing it shows the piston in mid stroke and the Shuttle valve covering both ports, is this a small mistake, if not how does the steam get into the L/H. side to blow the piston to the bottom and as the shuttle is hard against the R/H side how are you to move it to get steam behind the piston to blow it to the top. ?As I said, the drawing (made with paint) is not correct. I only made it for showing ports and valve arrangment. The auxiliary valve would of course have to be on the other side so the piston ram could move it to where it already is in my drawing. This would then cause the shuttle valve to switch position as well and the piston would go into the wrong direction. BUT: On my Pump, the ports between the auxiliary valve and the shuttle piston are crossed. And that would then make everything right. As you see, my drawing can not be drawn correctly but I did chose to draw it that way because crossed ports in that drawing might confuse someone. Cheers Florian