Thank you so much to those who answered my question about whether there is such a thing as a "one cow milk machine". Ok, I am going to make up my own as suggested from parts on Ebay. The surge tank I understand (I think..LOL!) but I have a couple of questions, on the pump however. I see you only need 12 to 15 lbs of pressure and I like the idea of using a medical pump. How much psi is that? Also, I am assuming that too little pressure equals no milk, but if I get too much pressure won't that hurt the cow and how do I know what is enough?? Can you adjust the medical pumps or the correct pressure?? Thanks again!

-- Karen (db0421@yahoo.com), August 28, 2001

Answers

Karen, yes, too high a vacuum level hurts the cow over time. 12-15 pounds vacuum is the range you want to milk in. Too low means the machine will keep falling off the cow and no milk. :) Any pump ought to have a gauge on it that shows the level the pump is working at, and there should also be an air regulator somewhere in the system that will allow you to fiddle with the amount of air entering the lines. This regulator could be on the pump or on the line running to your milking machine from the pump. It can be nothing more than a series of weights hanging from the line that lets more or less air into the system depending on how much weight you have added. It sounds confusing, but once you get the system in front of you it is easy to figure out. I don't know anything about medical pumps, so someone else will have to address that one for you. :)

-- Jennifer L. (Northern NYS) (jlance@nospammail.com), August 28, 2001.

I think we should check the vacuum values. Vacuum is just some pressure less than atmospheric pressure which is about 15 pounds per sq inch or around about 30 inches of mercury. Vacuum is often expressed in inches of mercury and always has to be greater than zero and less than atmosperhic! '15lb of vacuum' would be a very fine vacuum indeed and attainable only in a laboratory.

My guess us that the correct terms is 12 to 15 inches of mercury.

-- john hill (john@cnd.co.nz), August 29, 2001.