hopefully some clarification

[jim81147]

I was hoping that someone could help me out with a question I cant seem to find the answer for . It has to do with Dutch press pressure figuring . I have read alot of threads that state how to measure MA from measurements of arm length , fulcrum point and such and all the formuls I have seen say to enter into the equation the weight of the arm and pressure rod ( vertical part ) to find finish pressure . I have weighed all the parts and come up with 8 1/2 pounds for my press . When I go to verify that weight with a scale under the pressure rod I get a weight that is much greater than 8 1/2 . Since I dont have a scale that reads more than 15 pounds ( and I may do cheeses that require less than that ) that I trust and can fit in the press is there a way to figure it mathmatically? I understand that the 8 1/2 is ( by design) increasing on a sliding scale due the the leverage of the beam itself . Maybe there is no way to figure this and that is why everyone says to just add in the weight of the arm ? or maybe i am not understanding something as well as I thought I was? Thanks for any help.

[smolt1]

  The easy way to measure the tare weight ( the pushing weight with no weights on the lever arm ) is to just put a scale where the mold would go and measure the pressing weight with no weights on the lever arm.

  To calculate it is a little harder. It is composed of two weights.

      1) The weight of the pusher is one component ( no leverage involved ).

        2)The other is the leveraged weight of the lever arm.  To find this you need to find the center of gravity of your lever arm. Set your lever arm on a table and balance it on a round dowel like a pencil. when it balances mark where the pencil is on the lever arm. This is the center of gravity of the lever arm. This is where the weight of the lever arm is concentrated. Now calculate the MA of a weight at this point and then the pressing weight component of your lever is the weight of the lever times this MA.
 
       Now add #1 and #2 and that is the tare weight of your press.