pressing weight question

Started by steffb503, May 10, 2014, 10:43:13 AM

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steffb503

I am trying to figure this out and drawing a blank, Yes it happens after a certain age.
Typically I press 4 wheels ,8" diameter at a time. 2 on each press. My press is a version of Saliors.
What do I need to do to press 3 on each.
I can place a board on top of the two and then the third on top of that but at what weight do I press. What do I go by, the total area, just the area of the top wheel, or none of the above?

jwalker

You can't press them like that and get equal pressure on each , the top one will get almost twice the psi as the two bottom ones.

The top one would get the full weight of the press , the bottom two would get the full weight of the press , plus the weight of the top cheese , divided by two.

So if top cheese weighs 4 pounds , and press weight is 10 pounds , top cheese gets 10 pounds pressure , bottom two get 14 pounds divided by two , which is 7 pounds each , or 30% less than the top one.

You need a board that will span all three at once without too much flex , a piece of 2 x 12 maybe.

steffb503

So how do they do it in this pic?

Alpkäserei

Alpine cheesemakers often will stack 3 or 4 cheeses on top of each other from the same batch and press them. THis has worked well for centuries. Just place a board between each two cheeses.

smolt1

In the picture, lets say each of the 3 cheeses weighs 5 lbs and the press is pressing with 100 lbs.

The cheese on top is getting the full 100 lbs from the press.

The 2 cheeses on the bottom are dividing the weight ( if you position the top cheese exactly in the middle ) from the press.
They also have the additional weight of the top cheese, so the total weight on them is 100 lbs plus 5 lbs. but each is only getting 1/2 of that weight.

The result is 100 lbs on the top cheese and (100 + 5)/2 or 52 1/2 lbs on each of the bottom cheeses.

To get the pressure, divide the weight on any one of the cheeses by the area of the top of that cheese.

jwalker

Quote from: steffb503 on May 10, 2014, 01:57:28 PM
So how do they do it in this pic?

They could just be sitting there temporarily while the lady in the pic is setting up the press , in the very back , there is two cheeses on top of the two bottom ones , that would be fairly equal pressure , not accounting for the weight of the top cheeses.

In her hands she has a metal plate like the one at the top on the back two , she could be getting ready to add two more cheeses to the front ones and put the plates between the press and the top cheeses , just a guess tho.

But the front two are still unequal as they are currently positioned , with the top ones getting nearly twice the pressure of the bottom ones , even a skilled cheese maker can't change the laws of physics. ;D

You could probably get away with the "one on top-two on two bottom system" if you rotated the cheeses on a regular schedule , it would take some timing and experience to get it right tho.

John@PC

Quote from: jwalker on May 11, 2014, 12:19:58 PM
They could just be sitting there temporarily while the lady in the pic is setting up the press , in the very back , there is two cheeses on top of the two bottom ones , that would be fairly equal pressure , not accounting for the weight of the top cheeses.
But it appears that the front two presses are already loaded.  Also, it looks like there are 8 large (Kadova, I assume) molds (12 kg?) and the two molds on top at the back are smaller (8-10 kg?). Anyway, it's a beautifully made press (enlarge the picture and you'll see what I mean).

jwalker

Quote from: John@PC on May 13, 2014, 12:54:51 PM
But it appears that the front two presses are already loaded.
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It sure does , with a setup like that , I imagine they have a system and have done it many times before.

The middle one has an extremely long arm , a lot of leverage there.