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Excellent response, FarmerJD, as always.

I agree about the size of the hole where the pivot pin is installed. A small miscalculation in my design put the hole directly in the center of the board rather than the final position which offsets it. Thus the larger than designed-for hole. Hey, future builders can benefit from my faux pas. 

So then...I shouldn't go ahead and max out the press by applying my 75 lbs of barbell weights to it? What's the integral strength of that piece of wood holding the pivot pin? Nah, better not, I have important cheese work to do.

-Boofer-

I never intended to suggest Boofer's machine wasn't perfect, but just in case I can't use the same materials and have to change the design slightly, I needed more data.  It sounds like a bit of reinforcing at the top will make everyone sleep easier at my house.   

I originally wanted to use the off-the-wall design but when I described the forces involved (and drilling a hole in a stud) that plan was vetoed. 

Boofer, I can tell you approach things kind of like I do: hands on. I hung 2 ceiling fans Saturday and the first one took an hour; the second one 7 minutes. Experience is priceless.
Marta, I wouldn't give up on the wall press because it is so much less work to build it. And the arm can be detached and put away much easier than a big press. Good luck.

I made this one for a couple dollars
http://www.cheesemaking.com/store/p/50-Off-the-Wall-Press-Plans.html

Quote from: Marta on March 02, 2011, 01:43:29 PM
Not being a physics adept, I wonder what amount of pressure is brough to bear on the fulcrum end?  I would think it would be considerable.   And is it upward pressure, or toward the pulleys, or what (i.e. where does it need reinforcing at that end)?  I'd like to build one of these but I don't want it to fling pieces of itself into orbit.   

Sorry if this is covered elsewhere but I can't find it.

Hi Marta.

I too would endorse JD's advice, whatever it might be. But since you are looking for more ideas here's a thread that might be useful:
RenaissanceM's Press

Quote from: Marta on March 02, 2011, 01:43:29 PM
Not being a physics adept, I wonder what amount of pressure is brough to bear on the fulcrum end?  I would think it would be considerable.   And is it upward pressure, or toward the pulleys, or what (i.e. where does it need reinforcing at that end)?  I'd like to build one of these but I don't want it to fling pieces of itself into orbit.   

Sorry if this is covered elsewhere but I can't find it.

it will be purely up provided that all the other forces on the arm are purely vertical and your arm is level.  The force will also be equal to the force your press is exerting on the cheese minus the weight at the other end.  It needs to be that way to balance the forces out and not have the arm in a condition it is accelerating.  So this is not as much force as the point it attaches to the ram, but it is a significant amount of force.

It becomes somewhat more complex if you are say using pullies and are not putting a purely vertical force on the arm, or the arm is at a significant angle.  Small angles are fairly ignorable for this unless you had some strange construction that small horizontal forces on the arm would induce failure in your design.

Quote from: Boofer on March 02, 2011, 03:05:21 PM
Excellent response, FarmerJD, as always.

I agree about the size of the hole where the pivot pin is installed. A small miscalculation in my design put the hole directly in the center of the board rather than the final position which offsets it. Thus the larger than designed-for hole. Hey, future builders can benefit from my faux pas. 

So then...I shouldn't go ahead and max out the press by applying my 75 lbs of barbell weights to it? What's the integral strength of that piece of wood holding the pivot pin? Nah, better not, I have important cheese work to do.

-Boofer-

It would probably be a good idea to test it with any weight outside for a moderate duration before using that weight to make cheese.  That way if you have a structural failure it will be in a better place for that to happen.

Quote from: FarmerJD on March 02, 2011, 03:41:01 PM
Boofer, I can tell you approach things kind of like I do: hands on. I hung 2 ceiling fans Saturday and the first one took an hour; the second one 7 minutes. Experience is priceless.
Marta, I wouldn't give up on the wall press because it is so much less work to build it. And the arm can be detached and put away much easier than a big press. Good luck.

But if she isn't permitted to tie it into the structure of the wall at a stud I would not trust the integrity of wallboard to deal with this.  The vetoed comment suggests to me that tying it into the structure of the wall the way it would need to be is unacceptable for some reason.

Quote from: Pondering Turtle on March 03, 2011, 01:24:53 PM
The vetoed comment suggests to me that tying it into the structure of the wall the way it would need to be is unacceptable for some reason.

Yeah, her husband (or S.O.) doesn't want her drilling holes in the studs.

-Boofer-

Since I put my studs in, and neglected to cover them with drywall, I had to ask nobody if I could drill into mine!
My only real concern was when I was trying to achieve 20PSI using an 8 inch mould, was the half ton upward force on my basement ceiling. (20x50.25=1005lbs)

My wife actually asked me if I would lift the house. And while I shrugged off her concern with a "Oh not a chance", I was secretly crossing my fingers.

The notion of tonnage upon a poor cheese had me stumped for a while. Thoughts of stuff like Wayne lifting his house did indeed cross my mind! Once I figured out the counter forces involved I realized it really isn't all that much if MA is used to best advantage. The Dutch Press and variations are by far the best. The idea of tying into a stud being the easiest way to do this, and you probably won't lift your house. In my case, I had a concrete wall where I wanted to build my press and wasn't going to drill into that, so I figured out that a long and sturdy base would be enough to counter a 70 lb weight, double pulley and MA of 5.5 gave me a sizable amount of weight on my cheese.

The press in the photo is sitting on a bench, not tied to any wall, the concrete cylinder is about 35 Kg so the weight upon the cheese is just over 350 Kg. I later added a second pulley to double this amount.

Quote from: Wayne Harris on March 03, 2011, 06:28:30 PM
My wife actually asked me if I would lift the house. And while I shrugged off her concern with a "Oh not a chance", I was secretly crossing my fingers.

That brought a smile to my face. 

-Boofer-

I can just see Wayne's next thread... "Using a house as the weight on a Dutch Press: best practices"

"but honey, I HAVE to get rid of these mechanical openings"

coffee joe, I like the way you think.  What is the base, and how is the upright attached to it?  Did you have these materials lying around the house or is there a road sign somewhere  in your town now standing on one leg?  (a serious question... I quick shop of the big box stores today did not find any material sturdy enough for this project.) 

I was considering finding a used engine hoist and taking out the lift piston, but your idea looks easier. 

Marta,

The engine hoist is the same principle. In my case the base is a 10" wide and 4" thick slab of hardwood. The riser is from a scrap yard that had angle iron from a power tower, but a pair of 2X4 would work just fine, the arm would work in between them. The length of the arm is  50" and the fulcrum is at 15" Need to fix the risers to the base well, I embedded the angle iron into the wood base and fixed with 4" X 3/16  wood screws.  Make the arm just a bit longer than the base you have and it won't tip over.