I made my fifth cheddar, pressing it with my new compound-lever press. The make didn't go exactly right -- acidified too quickly, and I think the curds got too dry -- but the press worked wonders. The first two pictures below show the final pressing, at 300 lbs (6 psi) -- using a mere 12.5 lbs of weight on the lever! (24x mechanical advantage). This is twice the maximum pressure I could get with my old press, and it really made a difference -- in spite of the curds being very dry, it knitted together beautifully.
The last two pictures show the finished product ... and an unexpected problem caused by my new, more powerful press -- the follower I have used is a bit thin, and apparently it bowed under the pressure, giving the cheese an unsual shape. But no matter -- when I cut off and tasted the "flash" (where a bit of cheese squeezes past the follower), it was fabulous -- hopefully a promise of things to come. Now I just have to wait 8 months -- I am planning to open this at Christmas.
Oo, pretty! You get a cheese!
What can I say - Other than - ABSOLUTELY amazing. :)
And da daa da da daaaaa ( trumpet in text - or morse I'm not sure how to make a loud noise) a cheese !!
-- Mal
Thanks, Stinky and Mal!
Dr. Awake: I guess I'll chime in too! AC4U.
Kern
I'm still visualising it all made of wood.....
I'll give ya a cheese just for the mechanics involved!! LOL Beautiful cheese Andy!! AC4U!!
Quote from: OzzieCheese on April 13, 2015, 03:47:54 AM
I'm still visualising it all made of wood.....
The cheese, or the press? :)
I seriously considered going with all wood. The stumbling block for me was the ultra-high mechanical advantage I was after -- at MA=24, the ram only moves 1/2" or so across the full range of motion of the main lever. This seemed to necessitate a screw adjustment for the ram; for a ram that is adjusted by a pin through spaced holes, I wouldn't want to put holes any closer than 1" spacing to be sure of sufficient strength, especially when pressing > 300 lbs. (Maybe this is too conservative -- my engineering consists of TLAR [That Looks About Right].) Of course, a wooden screw would be possible, and I really, really thought about that. I decided against it for various reasons -- first, I have the tools to cut the metal screw and nut, and welcomed the chance to try out that challenge; second, I don't have the tooling to cut a wooden screw and nut (though I was seriously tempted to make the tooling -- maybe someday); third, even if I did make the tooling, the wooden screw would need to be bulkier* to have similar strength (again, maybe not necessary, but TLAR); and finally -- though this was not evident until I put it into use -- the ability to "spin" the metal screw (i.e., give it a good twirl and it keeps spinning a few revolutions) is really nice for quick adjustment up and down; I don't know that a wooden screw and nut would allow that sort of free motion.
All that said ... after using this press a grand total of one time, I think I will probably leave it in the 8x setting 90% or more of the time. At MA=8, I can easily go up to 400 lbs of press (I have two 25 lb weights that can go on the main lever) ... and more to the point, at MA=8, there is up to 2" of travel on the ram. If I redesigned the press for a fixed MA=8, the ram could simply be a length of 1.5x1.5" hard wood, with holes drilled at 1" intervals for pegging through the secondary lever, thus allowing adjustments of 1" at a time. I'm still not sure how well that would work -- I could envision a situation where the cheese springs up enough that one hole puts the main lever a bit too high, but the next hole puts it too low not to run out of room -- but maybe having a 1/2" spacer that can be inserted as well would solve that issue.
*The issue with bulk may not seem like a problem ... until you start to draw out the relationship of the various parts. If you look at the plans (in the first post in the thread about the press), you can see that in the current design, the pivot point for the secondary lever is 2" from the point through which the nut for the ram swivels. Attachment points for the secondary lever to the main lever are at 4", 5", and 6" from the pivot point; this allows the secondary lever to adjust from 2x, 2.5x, and 3x MA. (This is then multiplied by the MA on the main lever, which adjusts from 4x, 5.3x, and 8x, for total MA of 8x, 13.33x, and 24x.)
The vertical pivot arm on which the secondary lever pivots is a length of 1.5 x 1.5" maple to provide sufficient strength (TLAR!). The metal nut through which the screw passes is likewise 1.5 x 1.5". This means that there is .5" of clearance between the edge of the nut and the edge of the vertical pivot arm -- clearance which is necessary to prevent these parts from rubbing as the press goes through its full motion.
Let's say we make the wooden screw 1.5" in diameter, and correspondingly the wooden nut 2.5" wide to allow 1/2" of "meat" in the side walls (TLAR :)). Now, to get the .5" of clearance, the closest the pivot point can be to the point through which the nut swivels is 2.5" -- which doesn't seem like a lot of difference, but let's follow it out: the attachment points at the other end of the secondary lever would be at 5" and 6" (or could go 6.5") from the pivot point -- can't go any more than that without running into the upright part of the frame that supports the main lever. This means the MA of the secondary lever would be 2x and 2.4x (or 2.6x if we went with 6.5). Meanwhile, the MA of the main lever, assuming we keep the vertical arm vertical, would correspondingly be 4.57x and either 6.4x or 8x. Multiplying these out, the final MA would be 9.14x and either 15.36x or 20.8x. Messy -- I'd much rather have nice even numbers of MA to work with so that it is easy to calculate how much weight to add.
Of course, all of the above calculations are based on the current size of the overall frame. That could be adjusted to take into account the bulkier components ... but as you adjust the frame to allow the secondary lever to be longer, you also mess with the length of the main lever, keeping in mind the need to allow clearance for the weights as the lever moves to the bottom of its range. And the longer the main lever is, the greater the MA that it provides to the equation -- and one of the non-obvious issues is the need to have a bottom-end MA that is not too exorbitantly high, to allow simple weights to be used on the main lever. (Again, part of this is to make it easy to calculate the final press weight.) In fact, one of the key issues that drove my design was the possibility of configuring the secondary pivot in such a way that I can press with an MA of only 2, should I ever need to trade less total press weight for much finer control of the weight.
Well, all of this was way more than you wanted to know. :) As was said in the thread about the press, I'm afraid I'm a bit obsessed -- simply because I have been thinking about this, and drawing up ideas, and testing out the results in rough simulations, for way too long. Darn it, Jim, I'm a cheesemaker, not an engineer! (A little something for the Star Trek fans among us ...)
The cheese looks great, but I have to say:
I am in awe of that press, not to mention the mechanics behind it all - wow!
Definitely cheese-worthy!
Adam.
Andy-----just for the heck of it----you really should try some Lignum Vitae for your screw----probably the hardest, densest wood around-----it machines like metal using the same tooling you have-----it's self lubricating---it was used as bearings in hydro turbines on dams -----it can't be glued however. And it is so dense it sinks in water.
I have used it on various projects over the years, almost like machining some plastics. Of course I never tried an acme thread. The government had planted a bunch in Florida for the war effort, I used to get some from a friend down there.
Qdog
I'd love to give lignum vitae a try! I've never priced it ... I assume it is probably at least a little bit pricey?
I have to confess that the vast majority of the projects I do use recycled materials -- the wood in the press is from old discarded school desks (remember the kind that had a hard maple writing surface that curved in from one side?), and the metal is from various scavenging. Yes, I'll buy new when I really need to, but it hurts me deeply to pass by something that could be recycled into a new life -- thus the reason for all the, ahem, recyclables, in my garage.
I guess I should say that my wife has a different name for my "recycling" and "scavenging," but "junk" is such a hurtful word, don't you think? :)
As I consider my self " The Hyena of Junk" I too, hate to buy things, if I don't need too. I got my hard maple from old school bleachers. As far as lignum vitae goes, and the Argentine cousin---I believe they are both protected----so it would have to be old stock and probably pricey---if you can even find pieces big enough. That's why I mentioned Florida, back in the 80's, it was still growing there, and most people didn't have a clue what it was, my friend used to send pieces from trees in his back yard---so, know anyone in Florida?
Qdog
Not a soul, unfortunately. But my daughter is headed there for a school trip (choir) in the near future ... surely the director wouldn't mind if she stashed some wood in the bus??
Update on this cheddar -- here is a picture of it after a week of drying, just before I vac-sealed it. (I decided to go the easy route, since the next couple of months will limit my time for rind maintenance.)
I'm super pleased with the knit -- there are just a couple of little wrinkles as you can see in the picture, but easily it is the best knit I have achieved on a cheddar.
Still looking for the promised picture! :( Ah, there it is! :)
Oops! I added it to my previous post just now. I plead distraction for the best of reasons -- I was in the midst of making some cheese! (Lancashire this time)
Forgiven :) now where the Lanc make ?
-- Mal
Lignum Vitae is available but not cheap if you are looking for large pieces. http://www.bellforestproducts.com/lignum-vitae/wood-blanks/ (http://www.bellforestproducts.com/lignum-vitae/wood-blanks/)
I have turned a few crochet hooks from it and love the way it holds up.
Quote from: OzzieCheese on April 13, 2015, 03:47:54 AM
I'm still visualising it all made of wood.....
Mal, I've updated the thread on making this press to include a modified version of the plans for all-wood construction: https://cheeseforum.org/forum/index.php/topic,14493.30.html (https://cheeseforum.org/forum/index.php/topic,14493.30.html)
Thanks for the updated drawings. I just need to score some wood...
-- Mal