Dutch Cheese Press Prototype Wallace1

[KosherBaker]

First off, apologies for such a long post.
OK so here are my plans for a Dutch style cheese press. Please excuse the child like appearance of the drawings as I'm clearly not much of an artist. The goal was simplicity of design that can be reproduced by anyone, and also be flexible and powerful. The measurements are in our crazy American Imperial system. My apologies to the folks enjoying the more advanced Metric system, it's a lot easier to convert to Metric from Imperial.
I initially was going to buy the wood at Lowes, but surfing their site I found nothing but "Green" Douglas Fir, which is sold as I understand it with quite a bit of moisture still in it. This moisture then leads to the wood warping as it drys. Navigating over to the Home Depot site I noticed that not only do they sell the same "Green" Douglass Fir for less, but also sell the "White" Douglass Fir, which they tell me is the same wood but dried. It also has a much better finish to it. They also sell redwood in the 2"x4" category, although it appears to be 3 times the price. I'm curious to hear from the you, what you think about using redwood instead of fir. Their Janks Hardness scale appears to be identical, however, the Home Depot clerk that I telephoned insisted that redwood is a superior wood and is less prone to warping.
Anyway without further ado, here's the shopping list:
1. One 2in x 4in x 8ft ($2.12 Fir, $7.47 Redwood) - Cut in half to form the bottom sides of the press.
2. One 2in x 4in x 8ft ($2.12 Fir, $7.47 Redwood) - Cut in half to form the lever.
3. One 2in x 4in x 8ft ($2.12 Fir, $7.47 Redwood) - Cut into 6 equal 16 inch pieces for the bottom.
4. One 2in x 4in x 8ft ($2.12 Fir, $7.47 Redwood) - Cut into 5 pieces. One 32 inch piece for the plunger and four 16 inch pieces for the bottom.
5. One 2in x 8in x 8ft ($4.18 - Fir, ) - Cut into 4 pieces. One 33 inch piece for the back panel of the press that will contain the 2 fulcrum openings. Two identical 20 inch pieces to form the plunger guide/stabilizer. And one 23 inch piece to form the front panel of the press. I'm thinking that 2x8x8 may be too much for this application and 1x8x8 may actually work better so I will probably go with that, even though they appear to be more expensive, unless you guys think otherwise.
 
Total (from $12.66 for Fir to close to $50 for Redwood). BTW Home Depot offers a cutting service. Straight cuts only. First 2 cuts are free after that it is $.50 a cut. Since there are 14 straight cuts here that can be an additional $6.00. And even though I have the tools to make the cuts I will probably do it at the store since I live in an apartment now and want to make as little noise as possible.

Last point. I'm hoping to get feedback on the overall design, and especially the (old school) connection style of fulcrum. I decided not to use a bolt since it is difficult to tell what kind of weight it will withstand. With this connection I have 2 inches of wood for support.

[DeejayDebi]

I don't know if it's me or what but I see 3 of the same pciture Rudy? I can't see what you are going to do with thee cuts.

[KosherBaker]

I don't know if it's me or what but I see 3 of the same pciture Rudy? I can't see what you are going to do with thee cuts.

Hi Deb.

I included the JPEG so that it can be seen here in the thread, and I also included the PDF because it scales/enlarges the images much more gracefully than the JPEG.
If you make the drawing a bit larger you'll see that each block has a label, italicized, that forecasts what its job is going to be. Like the top most shape says Press Bottom and the shape just below it says Back Board and so on.
Here's my idea for construction. Going down the shopping list.
The 2x4 in item 1 will be cut in half and will form the 2 long 48in sides of the bottom of the press, as you see in the top picture.
The 2x4 in item 3 gets cut into 6 identical 16in pieces. Those pieces will form part of the bottom of the press. 3 of them will be perpendicular to the 2 long side legs, thereby bracing them. and the other three will begin to form an eventual bottom for the mould. That is the left side of the top most picture.
The 2x4 in item 4 is cut into 5 pieces. 4 of them will be of equal 16in length and will complete the bottom of the press where the mould goes. The 5th cut will be 32in long and will be used as the plunger.
I plan on placing the 2x4 with the long 4in side standing and the short 2in side being on the ground. That should give me maximum stability and extra space to join the back board to.
The last 2x4 in item 2 is also cut into 2 equal parts and will make up the lever to which the plunger will be attached. There are two fulcrum openings in the backboard to receive these two boards. The two openings are 2in apart which is the width of the plunger.
So the back board and the front board will be perpendicular to the press bottom and the Plunger Aligners will be fastened to them.
The plunger aligners are identical in size and have holes in the middle of them for the 2x4 plunger.

So for example. My lever arm will be 48 in - 2 in inside the fulcrum = 46in. My plunger should be about 8 in from the fulcrum point. So 46 / 8 = 5.75 Mechanical Advantage.

Now I'm not sure if I made things more clear or if I confused people even more. 
Either way thank you for your feedback Deb and let me know.

[DeejayDebi]

Should be extremely stable and functional. The two guide will keep the plunger from sliding giving you lopsided cheeses. That will be nice also. 5.75 MA will do a big cheddar for sure. Looks good to me hon! Can't wait to see it.

[RenaissanceM]

Very nice KosherBaker. What type of max pressure/weight are you hoping to apply? A tip from my experience building my Dutch press was that every material has a psi rating. If you use 18/8 stainless steel bolts then you can be certain they can handle ridiculous amounts of pressure (I believe s.s. has a tensile strength of 120,000 psi). I would give you a heads up though for the wood and where you intend to use it in parallel capacity as they can't take lots of shear (parallel to the grain) pressure regardless of the type of wood. That was one item I had to consider, which led me to reinforce those points (i.e. fulcrum). Keep us updated.

[KosherBaker]

Bravo to you two for having actually understood my lengthy ramblings above.

A tip from my experience building my Dutch press was that every material has a psi rating. If you use 18/8 stainless steel bolts then you can be certain they can handle ridiculous amounts of pressure (I believe s.s. has a tensile strength of 120,000 psi). I would give you a heads up though for the wood and where you intend to use it in parallel capacity as they can't take lots of shear (parallel to the grain) pressure regardless of the type of wood. That was one item I had to consider, which led me to reinforce those points (i.e. fulcrum). Keep us updated.

That's interesting to hear. So are you saying using a SS bolt through say a 4x4 would tolerate greater PSI than using the fulcrum design I specified? The pressure point will indeed be parallel to the grain.  I specifically used this design thinking it would have greater weight tolerance over the steel bolt design.  The wood I'd have to use for the back board would be a 2"x8"x8' Douglass Fir. As I don't seem to have anything else available here in Los Angeles to me in those dimensions.
Aside from the Janka Wood Hardness scale where could I get more info on this?

[Alex]

Janka Wood Hardness scale is secondary for the press design. Just google for wood strength and/or  properties, lots of info.

[Spoons]

Nice work KosherBaker! your plans should be quite helpful! Think you can post some pics when your press is done?

[RenaissanceM]

If I had to pick a readily available material then I would pick 18/8 stainless steel hands down over wood (off course for the size it will be much more expensive). S.S. has a yield strength of 30,000 psi, so don't hesitate to use it as a pivot point. I would be more concerned about the wood ripping apart from the pressure. That is why I reinforced my pivot point with metal decking material do transfer the pressure from the drilled wood.

[KosherBaker]

If I had to pick a readily available material then I would pick 18/8 stainless steel hands down over wood (off course for the size it will be much more expensive). S.S. has a yield strength of 30,000 psi, so don't hesitate to use it as a pivot point. I would be more concerned about the wood ripping apart from the pressure. That is why I reinforced my pivot point with metal decking material do transfer the pressure from the drilled wood.

OK I guess I have some reworking of plans to do. I'll replace the 2"x8"x8' with a 4"x4"x8' and the pivot point will utilize the metal bolt. A few questions.
1. Are there any untreated 4"x4" out there? Is it OK to use something treated in the press application?
2. Even using the bolt as the pivot point there's still pressure on the wood. Even if I go with the 4"x4" which I guess is what you are saying in the post quoted. So if using wood possible reinforcement should be considered. Is this correct?
3. In the current design. What if I were to reinforce the fulcrum points by attaching a piece of 2"x4" perpendicular to the back board just above the fulcrum openings? Would this still be weaker than using a 4"x4" and a metal bolt?

Nice work KosherBaker! your plans should be quite helpful! Think you can post some pics when your press is done?

Thanks you spoons, absolutely will do.

[DeejayDebi]

You could just use 2 2x4's

[KosherBaker]

You could just use 2 2x4's

Hmmm that's a great idea, although it would be a little tougher to mount them to the base. I knew there was a reason I cheesed you last week.

[RenaissanceM]

In answer to your questions:

1) there may be untreated wood out there, however as long as the wood or any water from the wood does not come into contact with the cheese/equipment, then you should be ok.
2) you're absolutely right. You can't go wrong by using the principle of "the chain is as strong as it's weakest link". I posted few pics below just to give you an idea how I reinforced by pivot point as the pressure was going to be at maximum at that point. Even though my metal attachment is still screwed to the wood, however the force is distributed over a greater area (that part is actually more of a security net in case the wood failed).
3) Regardless which orientation you use the wood, it will all depend where and how you're attaching it. If you attach it perpendicular however if the force at any other attachment points is parallel to the grain, then the wood will not be as strong at those points.
I hope I was clear enough.