My new press built by me

[IllinoisCheeseHead]

I built this press.  It should press upwards to 350 pounds and I spent a total of 55 dollars.  Will be using it today with my first cheese but did confirm the pressure and it is very easy to dial from 5 pounds to 350 pounds by the rate in which the springs compress.

Thanks

[smolt1]

Nice design. Where did you find those small diameter springs that go to 175 lbs when compressed?

[bratrules1]

Very nice!!! I also want to know where you got your parts? And are they stainless steel?

[IllinoisCheeseHead]

The springs in the photo can go to 125 lbs each (Maximum recommended) but I also have another set (4 inches) that go up to approx 220 each (maximum recommended).

The springs are chrome silicone alloy steel.  All the parts are stainless steel except for the rods.  They are zinc plated so should last a long time.  The springs are Raymond Die springs and can be purchased on multiple sites.  You will need a caliper or something to measure the rate of compression.  For example, with the springs in the picture, every 1/10 of an inch it will press  5.6 pounds.  It may sound too complicated but it is really simple to compute.  Every inch of compression will create 56 pounds of pressure.

[Kern]

It may sound too complicated but it is really simple to compute.  Every inch of compression will create 56 pounds of pressure.

Actually, each inch of spring compression will create 56 pounds of force - not pressure.  Pressure is force divided by the area the spring pushes on.  In this case the follower plate.  If your follower plate is six inches in diameter then each spring will put 2 pounds per square inch on on the cheese or 4 psi total.  While your work is elegant (and worth a cheese from me -  ) you can't escape a shortcoming of spring presses:  That is, as the spring pushes on the follower plate the pressure drops as the whey is expelled from the cheese (cheese gets shorter).  You'll have to compensate for this by re-tightening your press from time to time.  If you remember this and set your alarm clock for the midnight and three am tightenings you'll get years of service from your creation.   

[IllinoisCheeseHead]

That is correct.  One inch is 56 pounds putting pressure whatever is underneath.  You will then need to take into account the area of the item you are pressing.  For example, if the mold is 5 inches, the area is approx 19 inches.  To accomplish 2 PSI you will need to press at the rate of 19X2=38 pounds.

Indeed the pressure will relax also but should really not be that bad after the first 2 hours.  I based the design on models I saw on the internet that use the same concept.  I hope that after the two hours, the cheese would really not compress that much so we should not have to worry if we go from say 2.5 psi to 2.25 over 10 hours per se. 

Am I thinking this right?

[smolt1]

Yes you are thinking right, but on a 5 inch mold 2.5 psi to 2.25 psi is a reduction in height of the curds of .04 inch with your springs. I don't know if the shrinkage is actually that small on the last press.

[Kern]

Your thinking is correct.  However, I agree with Smolt1 who has build hundreds of lever presses.  (full disclosure:  I have his Sturdy Press).  Last Friday evening I put the press in full MA mode with almost 20 pounds on the end of the arm (~200 pounds of force).  I was using a slightly tapered 7-inch mold to do the overnight pressing on a 6-gallon cheddar batch.  The follower plate was made to fit the mold diameter at the bottom.  The cheese stood about six inches tall as I loaded it up.  It had already been pressed for three hours at increasing pressure to rid it of the final whey.  In the morning the cheese had compressed to about 5.5 inches high with about 3/4 of an inch of cheese extruded out between the gap between the follower plate and the inside of the mold.  This was trimmed off after demolding.  Had I been using a spring press the pressure might have dropped to nothing by morning.

I found that no liquid was expelled during this pressing and that the trimmings could not account alone for the loss of nearly 1/2 inch of height.  So, what explains the loss of volume?  Here is my theory:  During the last flip I thought the cheese was very springy.  It was still about 90F as I was pressing in a warm room.  In the morning the cheese was solid and had cooled to about 70F.  I submit that during the night any residual air in the cheese was slowly expelled by the high pressing force:  It simply migrated toward the low pressure area and was expelled when it reached the pressing cloth.

You'd never see this in most cheeses but a cheddar is a milled curd cheese and when cut into the small lumps that go into the press the little air pockets in the curd clumps are obvious.  Furthermore, you simply can't pack these lumps into the mold without creating voids in the process.  It takes constant high pressure to cause this entrapped air to diffuse out of the cheese.   A lever press can do this without attention.  A spring press cannot.   

[IllinoisCheeseHead]

Good information.

I am making a Gouda and so far the press has done 4 lbs (the weight of the top wood plus 2 pounds of water on top.  It did this for 30 minutes, then flipped and again for another 30 minutes with 4 pounds.  I flipped the cheese and when to 1.5 PSI for 30 minutes.  At the first 15 minute mark, I checked the compression rate and had lost less than 1/16 of an inch.  I re-tighten it to achieve 1.5 PSI again.  In 7 minutes I will need to flip and I will see how much I lost due to the cheese compounding.  I don't suspect it is going to be much.  The rind is fairly close now.

When I flip next time I will go to 2.25 PSI for 30 minutes.  That is a deflection of 7/8 of an inch and I will see where it is at after 30 minutes have passed.  I do agree that something with a constant pressure may be better but I wonder if the changes are small, unless you are making cheddar .  I don't care for Cheddar that much so perhaps I am good.  I think I will focus on making Gouda, Colby, Jacks and Havarty as well as the every once in a while blue

I will update this thread with my findings

[IllinoisCheeseHead]

Update -
I noticed that the caliper still would fit snugly at the end of the 1.5 PSI cycle.  I redressed the cheese and flipped it (rind is now basically closed) and took a PH reading.  Cheese is at 5.5 so I am almost at the end of the pressing face.

It is under 2.5 PSI now and will check the deflection at the 15 minute mark to see if I need to make any adjustments.  I am afraid that the next time I take the cheese out, I will be at the target PH. 

I don't know what the cheese will taste like but I did a lot of researched and was met all my targets.  Hopefully this is going to work out.  I am starting to feel brave enough to do this again next weekend

[smolt1]

It sounds like you have it under control. Since your springs increase the force by 56 lbs per inch, then 2 of them increase it 112 lbs per inch. So if your pressing at say 112 lbs and your height reduces by 1/4 inch, you lose 28 lbs. 28/112 is a loss of 25%. but if you are pressing at 224 lbs and lose 1/4 inch, you are pressing at 196 lbs, only a loss of 28/224 or 12 1/2 %.  It's above my pay grade to know if those percentages will result in  significant changes in the finished cheese.

[IllinoisCheeseHead]

Hi

On my last two presses, there was no loss of deflection from the beginning to the end of the press (At least that was measurable).  My last two presses were 2.5 and 3.25 PSI.  Although I only held it under 3.25 PSI for 15 minutes because the curd PH had already achieved my target PH.

So long as the cheeses don't shrink that much in a long pressure it should be fine.  I don't know how many cheeses lose that much height in the last press but I think I am safe with the types I want to make.  I was impressed how the press worked considering that it was done so inexpensively and compared to the ones I seen on the internet which were going close to 300.00.  Although mine looks more medieval (More like a torturing device than a press) 

[John@PC]

A very elegant design and I've really enjoyed reading the comments on this thread.  A cheese for you and I'm looking forward to hearing more  .