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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => EQUIPMENT - Forming Cheese => Topic started by: awakephd on April 06, 2015, 06:31:32 PM
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I've been working on a design for a new cheese press. My old press, the first one I made, has served me well for the past 16 months, but it only allowed me to go up to 150 lbs. of press, which was plenty for the smaller, 2-gallon, 4.5" diameter cheeses I started out making, but has been a bit too little for some of the larger, 4-gallon-and-up, 8" diameter cheeses I've been making lately, especially in hard-to-press varieties such as cheddar.
I have a prototype of a press that John@perfect-cheese.com has been working on which allows for substantially greater force by way of a pulley system (approximately 6x mechanical advantage). It is a light, elegant design which can be assembled and disassembled easily without tools, and it works very well. Likewise, Smolt1 (http://sturdypress.com (http://sturdypress.com)) has two lovely designs, one that offers selectable 5x or 9x mechanical advantage, with a design max of 350 lbs (though it can go higher), and one that can fold up for storage, with a design max of 200 lbs (though again, it can go higher). All three of these presses are designed to accept weights that hang from the main lever, though either of Smolt's designs could be modified to accept weights affixed directly to the levers.
As elegant and useful as all three of these designs are, they are not ideal for my particular situation. I need my press to stay in place on top of my cheese "cave," both for storage and during use. That means the entire press cannot be wider than 18", it cannot be clamped down, and it does not lend itself to hanging the weight. (It also means there has to be enough height on the base that I can set a bowl to catch the whey that presses out, but that is a minor matter.) Ideally, therefore, I want something that can accept weights directly on the arm of the press (I use weights from my weight machine) and that can select from low to very high mechanical advantage without having a lever extending out beyond the footprint of the base of the press (and therefore does not need to be clamped down or have a counter-balancing weight extending behind).
Inspired in part by a picture seen here on the forum -- unfortunately I can't seem to find the thread to link to -- I have come up with my own version of a compound lever press, one which adds selectable mechanical advantage (2x, 8x, 13x, 24x). I've included pictures below. The first picture is the picture I copied from the forum of the press that started my thinking. Following are a couple of pictures of the assembled press. As shown it is in the 8x configuration; to increase the MA, the vertical "arm" that connects the main and secondary levers is moved to either of the holes closer to the upright. Following that are several pictures of the frame and the parts, including a couple of close-ups of the acme screw and nut -- the first time I've machined one of those, so I was quite pleased with how it came out. Finally there are a couple of shots of the press in the 2x configuration.
I've also attached the plans. I've put a copyright notice on them, just because, but frankly I don't think this press would be commercially viable to produce. As you can see from the plans and the pictures, there are a LOT of parts, including at least one metal part (the nut) that would have to be custom-made (the screw could be bought off-the-shelf for a reasonable price). Thus, the selling price would have to be many hundreds of $$ to make it worthwhile as a commercial enterprise ... and I just can't imagine there are enough people who would be willing to pay the high price for this press. But if any of you feel inspired to make your own, have at it!
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Very nice Andy but I doubt the average person on here has the means to cut an acme thread. Looks expensive! AC4U for excellence in designing and building! ;)
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Thanks! As I said, not a commercially viable design. :)
It is possible to get an acme screw and nut for not unreasonable money, e.g. here: http://www.leevalley.com/en/wood/page.aspx?p=31134&cat=1,41659. (http://www.leevalley.com/en/wood/page.aspx?p=31134&cat=1,41659.) Problem is that that is a bit short (only 13" long), and the nut would have to be modified somehow. (This one may also be a left-handed thread, which is good for its intended use in a shoulder vise, but not ideal for the cheese press.) Alternately, one can get any length of acme threaded rod from various sources for not unreasonable money ... but again, the problem is the nut.
So, bottom line: if you want to make one of these, and don't have a machine shop in your garage ... try to find a machinist who really, really likes cheese!
By the way, I looked at making the design using a wooden ram. It is doable ... but the problem is that in the highest MA, the ram only moves about 1/2" total for the full swing (approx. 12") of the main lever. Assuming holes in the ram spaced at 1" (any closer than that would probably not be strong enough), one would have to use some sort of stacking spacer. It just seemed like it would be too difficult to use in practice, so I went with the screw.
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That is a beauty. Did you know that thinking that hard can cause smoke to exhaust from your ears. ;D
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You know if you extended the length of the nut you could make both the nut and screw out of a good hardwood.
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Andy----have you considered forgetting about the acme thread and nut and using a standard threaded rod and a split nut----since the main purpose of acme thread is quick movement---and nothing quicker then a split nut. This is a real nice design----well thought out---well executed.
Qdog
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Al and Qdog, both good suggestions.
I did give thought to a hardwood screw; a couple of reasons decided me against it. One is that I felt I would need at least a 1.5" diameter screw in hardwood, and correspondingly I thought I would probably need the nut to be at least 1" larger in width than the diameter, to give a minimum of 1/2" of "meat" in the side walls. To be honest, these figures are just based on TLAR engineering (TLAR = That Looks About Right :)) -- but if they are in the right ball park, that means the nut is going to be 2.5" wide. That then requires the two sides of the secondary lever to be spread that far apart, which means that the vertical "arms" that connect the secondary lever to the frame and to the main lever have to be 2.5" thick as well (or else have spacers). And then the upper part of the frame has to be spread that far apart, requiring more bulk to the uprights, and the sides of the main lever have to be spread. Plus, I think I would want the two "ears" on the nut (which allow the nut to pivot in the secondary lever) to be 1" in diameter (again, TLAR), so that means the width of the secondary lever would have to be increased from 2" to 3", and ... well, you get the picture. This is starting to get bulky, and I only have so much hard maple on hand, so I decided not to go with a hardwood screw.
I didn't give a lot of thought to a split nut, primarily because my initial musing didn't reveal any easy way to mount it or contain it as needed in the press. The key is the need for the nut to swivel in the secondary lever, or rather for the secondary lever to swivel around the nut as it moves through the range of motion. I may just not have thought of an obvious solution ...
Okay, those are the logical reasons. But the real reason? In addition to cheese making, I also count woodworking and metal working among my hobbies, and this gave me a chance to try out cutting an acme thread and nut. What more excuse could I possibly need? :)
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NOT the most fun of jobs but I see you point. BTW American white oak has a tensile strength of 770 PSI so it may surprise you. You could use a hardening agent on the wood to make the operation smooth. Did you cheat and use an acme insert for the threads or grind one up yourself?
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Insert? Heaven forbid -- we don't need no stinkin' inserts! :)
My old Cincinnati TrayTop is probably better suited to HSS than to carbide ... though since I hardly ever use carbide, I suppose I don't really know that!
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We have all of the acme thread inserts here for the CNCs but the apprentices are required to grind HSS to cut theirs. >:D Come to think of it, this may just make a good apprentice project. LOL
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Very elegant, Dr. Awake. A cheese from me! ;D
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Looking at IMG-4278, it looks like you glued the corners. That will make sure that your rectangular frame won't become a rhombus under the torque from the plunger pushing on the base. It's easy to think that when you only have 10 lbs hanging on the lever that the forces are not too great, but at your high MA that is 240 lbs trying to distort the frame.
Do you have much friction where the plunger goes through the 2 metal guides, because that seems to be my biggest problem in designing a smooth working press.
When you do a large Cheddar it will be interesting to see if the last high weight press will require a reset or if the small amount of compression remaining will make it at MA=24.
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Yes, glued and draw-bore pegged. I also pegged the ends of the base (where the ends are just in a rabbet rather than a dado). I am a bit concerned about how well the frame will handle higher pressures, not only these joints at the top, but also the joints where the uprights are joined to the base -- these are glued and also screwed from the inside. The first opportunity to test it on cheese will be this weekend, but I hope to do some accuracy testing tonight, and that may also give me a sense of how well it handles stress -- if I start to hear ominous cracking sounds, well ...
I spent a good bit of time thinking through the design of the guide. It actually consists of three pieces, not just two; in picture 4275 you can see the middle piece already joined to the bottom piece (lower right corner), with the top piece lying next to it. I machined these in such a way that they join together to form what is effectively a single metal guide that is 2.5" in length with only about .001" clearance in the bore. (And yes, as a home-shop/hobby machinist, I was quite proud of myself for machining this precisely enough to repeat the clearance of the bore even after disassembling and reassembling, though of course modesty prevents me from telling you this. :)) This provides a lovely, smooth sliding fit with almost no play -- at least in preliminary trials. Again, I'm anxious to see how it performs in actual use; this will be especially important since the screw threads offer an inherent opportunity for friction.
I finished all of the wood with plain mineral oil, standard practice for food-safe wooden articles. Conveniently, that also provides some lubrication and protection for the metal bits.
Hoping for cheddar on Saturday ...
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Andy ----if that's your first acme thread----your one heck of a hobby machinist!!!
Al----thought you were a Navy man? I would think Lignum Vitae would be your wood of choice? ;)
Qdog
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Although I work on the naval nuclear fleet now I retired from the Air Force in 1996. LOL
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Yes, first acme thread, but not my first machined part. And the pictures don't give you enough close-up to see the chatter marks down in the root of the threads. :)
I did some testing last night to see if the actual MA matches the calculated MA. I'm pleased to say that the match is quite good -- a small deviation from the predicted values, but since the scale I am using is not overly accurate, I felt that it was within the expected range.
I also tried a bit of stress testing, putting a 25-lb. weight on the lever with it set to 24x MA, for a calculated press force of 600 lbs. I let the weight down slowly ... but there was no creaking or protesting. I thought about adding another 25 lbs for a total of 1200 lbs press force ... but I chickened out. :)
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Yeah Andy, I don't think you'll ever need any more unless you decide to press hams under it. LOL BTW CNC turning centers get those same chatter marks, usually on the trailing edge. Your machine work looks excellent to me. Did you gage the pitch diameter on the threads or just make them fit?
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And yes, as a home-shop/hobby machinist, ........
Then am I correct in assuming that you machined the acme threaded "swivel" bolt that really seems to be the critical part of your design?
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Andy, If you want to see all the forces in play, try "Autodesk forceeffect". It is a free android app that will work on the Chrome browser. If you have a PC, just enable the Chrome browser and click the APP icon in the top left corner to get started.
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Yeah Andy, I don't think you'll ever need any more unless you decide to press hams under it. LOL BTW CNC turning centers get those same chatter marks, usually on the trailing edge. Your machine work looks excellent to me. Did you gage the pitch diameter on the threads or just make them fit?
Coming from someone who works professionally in the field, that is high praise indeed! But as you know well, "looks good" does not mean that it actually is made correctly. As a case in point, I'm afraid I did not gage the PD -- I confess that I still need to acquire a set of thread gage wires; I've always "cheated" and just made my threads until they fit a desired reference (usually something highly sophisticated and accurate like a hardware store nut. :)) In this case, of course, I didn't have a 1-6 acme nut lying around to test against, so I made the screw just by advancing the distance that "should" be correct, and then made the nut to fit. I figured it would be adequate for this purpose. Interesting to hear, by the way, that you get chatter even on the CNC ... but if something is going to chatter, I'm not surprised that it is an acme thread form!
Then am I correct in assuming that you machined the acme threaded "swivel" bolt that really seems to be the critical part of your design?
Yes, I made the nut, and you are right -- that is the critical piece. Fortunately, there is plenty of "give" in the system, so it did not require super-high accuracy. Of course, accuracy in a machine shop is rather a different matter than it is in the woodworking shop -- in this case, I wasn't worried if the ears were, say, +/- .010" from being perfectly perpendicular to axis of the threads, which is a HUGE tolerance in the machine shop ... but pretty near exactly on the money in the woodworking shop! :)
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If I were you I wouldn't concern myself with acquiring thread wires for acme threads as they, like the inserts, only work for one pitch. You would have to buy them for each pitch you wanted to measure. There is however, a computer program that will allow you to change the wire size for any thread pitch as long as it is within a certain range. If you need some numbers I would be happy to give them to you. Wires for a 6 pitch acme are Ø .08608". Usually you can pick up a cheap set of wires from McMaster Carr. On those large sizes you'll want a disc mic to measure them though as they are spread too far for a standard mic. http://www.mcmaster.com/#thread-measuring-wire/=wnh6j2 (http://www.mcmaster.com/#thread-measuring-wire/=wnh6j2)
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Andy, If you want to see all the forces in play, try "Autodesk forceeffect". It is a free android app that will work on the Chrome browser. If you have a PC, just enable the Chrome browser and click the APP icon in the top left corner to get started.
Thanks for the pointer to the app -- I haven't had a chance to try it out yet, but look forward to seeing what it has to show!
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You've got some serious press building skills, Awakephd!!
AC4U!!!
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Thanks!
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Here are pictures of a couple of final details that I finished up last night.
The first two pictures show the press, including the final details, in its permanent home on top of my cheese "cave."
The next two pictures show a close up of the first of the final details, a "ship's wheel" adjuster, to make it easier to move the screw up or down as needed. I had debated whether to go with a socket in the top end of the screw, into which I could put a standard 1/2" drive socket extension, or whether to go with something like this. Originally I was thinking that the ship's wheel route would require cutting a keyway ... but then I decided that I don't necessarily want to use this while under weight; rather to adjust as needed between changing weights, or if needed to move the screw up and down when pulling the mold out for flipping. So it doesn't need a super-strong drive system (such as a keyway); instead, just a pressure pad will suffice. If you look at the peg in the lower right quadrant of the picture, you'll see that one picture shows it unscrewed part-way, and the other shows it screwed in to provide clamping force. (The screw does not bear directly on the acme screw -- I don't want to mess up my nice shiny finish! :) Instead it presses against a pad of hard maple, which then presses against the acme screw.)
The last three pictures show a close-up of a detail that I transferred from my previous press -- a flanged knob that will keep a weight from sliding off the end of the lever. (In actual use on my previous press, the weights never seemed to have an inclination to do this -- friction was sufficient to hold them in place -- but I am not comfortable not having some insurance to make sure I don't drop a 25 lb. weight onto the floor!) The last picture shows the brass threaded insert in the end of the lever, into which the knob threads -- I wound up making the insert, because a) I didn't have one of the right size on hand, and b) this is something that only takes a few minutes to make out of brass. Actually, I made two, one of which is used in the "ship's wheel."
It is possible I will decide the ship's wheel adjuster is not the way to go, after all -- I can see that I will have to move it up and down to get it out of the way, and I don't know how tedious that might get; I may still machine the 1/2" socket in the acme screw, so that I can choose between the systems. But for now, I think I'm done! So today I am planning to make some cheddar and put the press through its paces.
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Okay Andy, this is becoming an obsession! LOL Beautiful work!!!
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One thing comes to mind about your press... ;)
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Okay Andy, this is becoming an obsession! LOL Beautiful work!!!
:) Thanks! As for the obsession ... I hate to end a project without finishing up all of the details that I had in mind from the start. And the ship's wheel was a lot of fun to make -- not too hard, just a bit of lathe work to make the hub, and a lot of lathe work to make the pegs (including a couple of extras that didn't quite work for one reason or another). And it just looks cool ... okay, maybe I am obsessed. :)
Spoons, I blush. I also can't imagine what something like this would have to cost to make it commercially feasible -- there are "just a few" hours of work invested in it ... at least that's what I try to convince my wife. :)
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Not sure what woodworking goes for but machine shop time is about $150.00 an hour. Mind you if you built in bulk you could get the screws/nuts at a bulk discount. You would want stainless steel of course, or CRES as it's known in the defense industry. 303 would do just fine.
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Andy----you really should get an award for aesthetics-----but out of curiosity---how many inches of thrust do you get in each position----and the rest of you guys, get your minds out of the gutter ;) That really did sound a little Kama Sutra.
Qdog
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Now I'm really blushing! :)
The main lever has a range of motion of up to about 16 inches max. In the 8x position, the full range of main lever measures about 2" of change on the ram -- right on the money for the calculations. In the 24x position, the full range is a bit less (due to how some of the parts interact), but still more than 12"; moving the main lever through its full range resulted in a bit more than 1/2" of motion on the ram. I assume the 2x and 13x settings would likewise give the expected amounts.
Given the small total movement especially in the 24x setting, you can see why I decided to go to the trouble of making the ram as a screw mechanism. For comparison, my original press used a ram with holes spaced 1", allowing me to use a pin to move it up or down as needed to get the right placement -- but that press only has 3x MA. Obviously, 1" adjustments are not going to cut it when the ram is only moving a total of 1/2"!
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Amazing and a wonderful piece of engineering. The detail and workmanship is without a doubt some of the best I've seen. Having made 2 presses i can appeeciate the thought and planning that goes into a project of this scope.
Impressive and of course a cheese.
-- Mal
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Thanks, Mal!
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I put the press into service yesterday, pressing a cheddar. Wow -- it performed wonderfully. It is so amazing to have what feels like an unlimited amount of force available; I topped out at 300 lbs (6 psi), which gave me a great knit with some over-dry curds, and still had 300 more lbs that I could have added -- woohoo!
First picture: 40 lbs. (5 lb weight, 8x MA)
Second and third pictures: 140 lbs. (17.5 lb weight, 8x MA)
Fourth and fifth pictures: 300 lbs (12.5 lb weight, 24x MA)
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With a great design and today's glues no rhombus appears. Fantastic!
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Andy - That is an awesome looking press. The quality is amazing. I would love to have a fraction of the skills you've been able to put into it. Have a cheese from me.
Shane
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Many thanks!
It has lived up to my hopes. I did have to get used to the fact that, with the far greater MA, there is no way to avoid spinning the screw up and down to put the cheese mold in and out. (Doesn't help that this "mold" is a repurposed bucket that is really a bit too tall.) And as I was afraid would be the case, I find that I have to move the "ship's wheel" adjuster up and down on the screw each time to get the amount of motion I need -- again a problem exacerbated by the overly tall mold. (I think a new mold is in my future ...)
But in spite of these challenges,the "ship's wheel" adjuster allows me to spin the screw quite rapidly, so the process did not feel burdensome. And the pressure available -- wow. I think I might have to try a Cantal, just to give it a real workout. :)
I also need to make up a 1 lb. or 1.25 lb. weight to give me a bit more fine-tuning when I'm at 8x MA and above -- the smallest weight I currently have is 2.5 lbs, which translates to 20 lbs on the 8x setting (and 60 lbs on the 24x setting!).
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When you do a large Cheddar it will be interesting to see if the last high weight press will require a reset or if the small amount of compression remaining will make it at MA=24.
Smolt, I wanted to come back to this -- as it turned out, when I set it for 300 pounds for the final press of the cheddar I just made, the main lever dropped about 6" overnight -- which meant it still had another 6" available to go. Of course, that means the ram only moved 1/4" -- but if you look at the picture in the thread I started about the cheddar, you'll see that some of this 1/4" was in the form of bowing the follower and thus the cheese under it.
So, short answer -- it looks like it can go without a reset by the time I get up to the 24x range. (And actually, I can go up to 400 lbs on the 8x range by putting 50 lbs on the lever -- it is designed to accept that much -- so honestly I may never need to put it in the 24x range. Though I did that anyway, this time, just to try it out and see if it would run out of room.)
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I'm a hobby woodworker as well but, I had to look up what a "Drawerbore" joint was, makes sense now :). Wish I knew that a few years ago... something learnt so today wasn't a total waste of time. I think that also the 'pegs' used when the technique was devised would have been had turned or whittled. Alas today the dowels we use today swell in the the presence of water (in the glue) a fill keep the joint tight. One thing though the modern dowels don't do and that is draw the tenon into the joint.
Thanks for the lesson :)
-- Mal
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Mal, I first learned of the draw bore technique from a TV show on PBS (our Public TV) called the Woodwright's Shop, featuring ways of working with wood from yesteryear, and have been using it on various projects for several years now. One thing -- I find that it is a bit tricky to get the offset just right. Especially in this hard maple, it only needed 1/32" or even less of offset. (A softer wood and/or a larger joint might need as much as 1/16"; if you are building a timber frame, maybe even 1/8".) Normally I use this on a mortise and tenon joint; for the press, however, the sides are not joined until they are joined to the uprights of the frame ... so in addition to using the draw bore to achieve a good tight fit against the shoulders, I also had to use clamps to make sure the sides were snugged up.
For the dowels ... I actually made those out of some of the maple from which the project was built. I used a simple but effective technique also learned from the Woodrwright's Shop -- I drilled a piece of 1/4" thick steel with a series of holes, each 1/32" larger than the next. Cut the maple to a square just a tiny bit larger than the desired final diameter, and pound it through the holes from larger to smaller until in reaches the desired size. The finish is a bit rough, but entirely serviceable. It is also important to put a slight bevel on one side of one end to help it engage the draw bore; I made the dowel long enough that this beveled part is fully extended beyond the joint, so that when I cut it off and sand it, the dowel fully fills the hole. (I hope that made sense ...)
Incidentally, if you are interested in the Woodwright's Shop, the host, Roy Underhill, has produced several books. I don't recall the publisher, and don't know if they are still in print ... but these days, you can find anything, including used books, via the internet. :) I've used a variety of useful techniques from these books / this show, even though I do most of my wood working with power tools.
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For those of you who would be interested in something like this, but all made of wood -- here are plans and some solid-model mock-ups of a version that is limited to 8x MA -- which can still easily to get 400 lbs, or even 600, with 50 or 75 lbs of weight on the arm.
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What wood would you recommend?
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Something strong. :) I used hard maple in mine.
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Based on the well known engineering principal of Close enough.... I would even contemplate an all wood version even going out to the 24 times design.. The individual parts can remade easily enough if I break one..
Thanks for this wonderful design -A cheese a day isn't enough..
-- Mal
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Nice work Andy. Thanks for sharing. Have a cheese from me.
Shane
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I have it converted to metric already - now I just need to find the wood.. Bunnings is rubbish and everywhere else is soooo expensive. Might try a recycling place
-- Mal
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I look forward to seeing your rendition! Since I made mine from recycled school desks, I think recycled wood is a great idea. :)
As for going to 24x -- I wouldn't be as concerned about the wood breaking as I am about the limited range of motion. At 24x, my screw-based press moves the ram a total of 1/2" or less across the full range of motion of the main lever. If you go this route, make yourself a series of 1/4" and/or 1/2" spacers to help adjust as the cheese compresses.
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Started collecting the wood and have found a good recyclers as well - though I think mine will turn out a bit chunky - but functional. I'll post progress shot :)
-- Mal
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I look forward to seeing it!
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On the weekend I got busy firming up the the now Ex-collapseable cheese press. I gave it an extra backbone on the base plate and screwed and glued extra blocks around the Base pivot point - not going anywhere now. But, would you believe it, there is still sufficient and noticable bending torqe applied at the bottom that I'm probably still going to produce 'Wedgies'. This has nothing to do with the design, it's more on my interpretation of the images I 'deduced' the dimensions from. Totally my fault. !! Should leave engineering to the Engineers :)
-- Mal
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Hi Andy
Well here is the 'Blocky' version of your wonderful design.
http://cheeseforum.org/forum/index.php?topic=14874 (http://cheeseforum.org/forum/index.php?topic=14874)
Had a lot of fun. I measure the handle and the fulcrum point and only came up with a MA of 3.5 so I increased the length of the main lever. Unless I've got more than I thought.
From the main upright to the secondary pivot is 10 cm
from the Secondary pivot to the first weigh hanging loop is 40 and to the Second loop 50 Cms. So am I correct that the MA is 4 to the first and 5 to the Second ?
-- Mal
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Mal, I am delighted to see this!
If I understand your measurements, it is a total distance of 50 cm from the fulcrum to the first weight loop (10 to the pivot + 40 more to the weight = 50), and 60 cm to the second -- is that right? If so, you actually have 5x MA at the first point and 6x at the second. The calculation is (distance from fulcrum to weight) / (distance from fulcrum to pivot). But keep in mind that the secondary lever multiplies the MA of the primary lever by 2, so your total MA would be 10x or 12x.
Can't weight (:)) to hear the report on its maiden voyage!
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Dry run today - Ohhh I'm excited
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Greetings Andy, Yes, I know this is an old thread, that's part of my reason for posting. Wondering why you haven't followed up. I was hoping to see a working model of you newest design.
What you've shown impressed me, that's isn't easy done. I'll go back and look over your model A, I do need a bigger press and I'm a maker of tools.
Thanks for posting
Richard
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Richard,
Mal (OzzieCheese) has a post somewhere showing his version of the wood-only design. I think it worked well for him - Mal?
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I have been talking to Andy about his design for a month or so and decided to make my own all wooden version of his press. I have about 6 man hours involed in the build, using my table saw, drill presse, 9" band saw and an orbital sander. I have secured the pivots with standard bolts, washers, and nuts (I am going to use clevis pins soon for quicker changes). So far I have been able to get an MA range of 7x to 14x. Since the pictures were taken I have corrected the short horizontal brace and rounded some edges for a softer look. I also used dowels to hold the main vertical support braces rather than screws. Holding the base to the vertical supports is probably the most critical aspect of this design (or any press for that matter) as the base wants to separate from the rest of the press under all the force (I found this out the hard way! screws will not hold it alone).
I have successfully measured 434 lbs (31 lbs x 14 MA) on a test for over 12 hours. I have since glued it together permanently and used the dowels as mentioned above and will be testing tonight with 49lbs. I also added an eye hook to the end to hang my weights. Thanks to Andy and his design. I truly believe this is the best homemade cheese press design.
Edit: I have about $26 in material invested into the entire press, it's just pine.
Chris
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At the risk of being just a bit self-serving ... a cheese for you for your build of this press!
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Nice press and great build! Press many great cheeses!!
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Maybe a quick release pin for the non-screw type ram could be used?
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Yes, it would be a handy way to adjust. The only thing I would caution is to be sure of the crush strength of the pin - this sort of pin is actually hollow, to accommodate the release mechanism. As long as the walls aren't too thin, the pin should be able to tolerate more than enough pressure ... I think ... but worth checking to be sure.
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Sorry for the late update, but I have successfully held 49lbs on the end of the new press I made. This gives me a theoretical 686 lbs of force.
I have since glued the press together, doweled the main vertical supports and rounded most of the edges. I also added the hooks on the end for the weights.
Here is the final pics of my new press.
I also added a pic of the first cheese I pressed, Piora (3.89lbs) straight from the press
Chris
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Great work -- imPRESSive! :)
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Nice little beast...
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Yes, it would be a handy way to adjust. The only thing I would caution is to be sure of the crush strength of the pin - this sort of pin is actually hollow, to accommodate the release mechanism. As long as the walls aren't too thin, the pin should be able to tolerate more than enough pressure ... I think ... but worth checking to be sure.
They do make these for quick-release wheel chair wheels so some of them should be rated fairly high.
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Yes, it would be a handy way to adjust. The only thing I would caution is to be sure of the crush strength of the pin - this sort of pin is actually hollow, to accommodate the release mechanism. As long as the walls aren't too thin, the pin should be able to tolerate more than enough pressure ... I think ... but worth checking to be sure.
They do make these for quick-release wheel chair wheels so some of them should be rated fairly high.
I plan on using 3" Clevis Pins for quick changing the ram and the adjustable slots for MA changes.
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Andy, this is a gorgeous press! Was it by chance inspired by this one (http://cheeseforum.org/forum/index.php/topic,8421.msg59142.html)? I go away for a mere five years and compound lever presses become all the rage!
I've often considered ways of compacting "my" design*, but ended up getting distracted from cheese-making before I got the chance. I've grabbed your plans and look forward to making some sawdust this season. It's good to see another woodworker here, too.
Cheers!
*Not my design, but as soon as I saw it I knew it was a great idea for a cheese press.
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Hi NW, and thanks for the compliment. No, not inspired by that press, but rather by an old-fashioned press that looks like it was made of cast iron. That said, I have looked many times at the press you linked to (and looks like you made), and there are a couple of big pluses and a couple of possible minuses that I see. The big pluses are 1) ease of construction / simplicity of design - far simpler than mine, and 2) potentially infinite adjustment of the MA. I have thought long and hard about whether I could make a press along these lines, with a built-in weight, that could be adjusted from, say, 10 to 1000 pounds by moving the weight, the points of attachment between the levers, and the point of attachment for the ram. In theory, I think something like this could be accomplished.
But here's the possible minus - the design as shown puts a pretty significant limit on the amount of travel for the lower lever, even when the MA is low. This in turn could mean needing to use either an adjustable ram (which the current design does not lend itself to) or shim blocks as the cheese settles. One way to resolve this might be to offset the levers so that they can pass by each other, rather than one directly over the top of the other.
The other possible minus, at least with the designs I've kicked around in my head, would be how to simplify the setting up a particular desired weight. There are three variables that would control the force applied: The placement of the weight along the top lever (perhaps dropping into pre-set slots); the placement of the connection between the levers; and the placement of the ram on the lower level. Might have to have a chart to show where to set each part to get the desired outcome, but it starts to feel rather complicated ...
One of these days, I hope to come up with something that will "do it all" with a single weight, but so far I'm still pondering!
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It is a bit of a challenge to find that sweet spot between simplicity and effectiveness. My addition to the original design includes an two-way-adjustable piston that increases variability, but I never put it in because simply changing weights, adding followers, and moving the cheese horizontally has given me everything I need fairly conveniently. Adding notches to move the weight would increase variability even more. But my goal is to get the thing smaller for easy storage, and your plans do that admirably.
I'd love to see the cast iron press if you have a link. I have an antique French cast iron corker that's beautiful, and I was actually thinking of designing an "antique look" cheese press, based on its design.
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Actually, the picture that inspired my design is in the very first post in this thread. :)
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Too easy. ;)
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Found photos of a similar antique. This is beautiful!
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That's a very fine piece of machinery.
Parts of me are fizzing......
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Very sexy, indeed. But there is a catch (isn't there always?) - the press shown in the picture has a fixed and extremely high mechanical advantage (MA). As best I can tell, measuring from the picture, the upper lever has an MA of around 11. The lower lever has an MA of around 4. And the pulley will add an MA of 2. Multiplied together, and you get an MA of 88x - and again, this would be fixed, not adjustable. This has some very important implications:
On the positive side, it would be simple to put a great deal of force of weight on the cheese - 5 lbs applied to the end of the chain would produce 440 lbs of force.
On the negative side, it would be much more fiddly to put small amounts of weights on the cheese To follow a regimen of, say, 5, 10, 20, 40 lbs of pressing for an alpine style, you will need weights of .059, .11, .23, and .45 lbs. No, not too hard for a machinist to make, but not something you can easily do with a jug of water. To put this in perspective, with an 88x mechanical advantage, a change in just about 5 grams applied - a teaspoon of water - would produce a change in force of 1 lb. (Yes, I know - mixing my measurements - but for the metric folks, the relationship is easier to understand, and most of us who use pounds and pints still have some sense of what 5 grams "feels" like.) You may be thinking, "no problem - just hang a jug and put in a teaspoon of water for every pound desired." Yes, but first you need to weight the jug, very precisely, and factor that in, and you need to make sure you are using exactly a teaspoon of water each time, and above all, even after you've done all of this, you need to take into account the friction in the mechanism, which will throw all of your calculations out the window. IOW, you'll need to do some very careful calibration ...
But here's the real negative: with a fixed 88x MA, your weight on the pulley will have to move 88" in order for the cheese to compress by 1" - even when you are only pressing lightly. Since the first pressing of a cheese can easily compress by 2-3", that means a LOT of adjusting with the screw mechanism, every few minutes, to keep the weight from hitting the floor. Even once the cheese begins to compact, a movement of only .10" on the ram will require nearly 9" of movement on the weight - so even at the end of the process, you may be having to watch out that your mechanism has not "bottomed out."
All of the above is why I wanted a design that had adjustable MA, so that I could use high MA only when I really need a lot of force, and lower MA when I need more control.
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AMEN!
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I love the mechanical aspect of the old one and the obvious workmanship gone into the castings. That said I've tried several designs
1. Screw press with a spring
2. Basic dutch press
3. smolt1s collapsible and
4. Andy dual pivot - wooden version
While they all pressed cheese to one degree or another my all time fav is the dual pivot design. I have put some awful pressures on the cheese in this press and it just keeps on cranking out cheese. I don't think I've even considered making another - I'm not even sure I could break this one (under cheese pressing conditions). I've even considered making an extra ram with cupped adapter to press apples (for Cider making) - its just that good.
just my 10 cents worth.
-- Mal
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If and when you start making apple cider with the press, we want to see pictures! :)
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Will be during the apple season. Later in the year.
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Hi guys - Mark here... recently into cheesemaking and thinking about building a new press. Realise this thread is a few years old - but wondering if you had any more thoughts since your last post OzzieCheese on this all wood version? I too am in Australia - so might need to score some Tassie oak from Bunnings as well. This style looks great and fun to make - all you guys have done a great job with it. Very inspiring. :D
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This is an old thread but it inspired my design for a compound lever press. I to used tassie oak but from Mitre10 not bunnings. I ended up with an 11 times mechanical advantage so it works quite well. The good thing about this deign is that it is stable and compact. Mine is also designed to come apart but it looks good just as an item.
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Beautiful job.... AC4U....
Bob
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This is an old thread but it inspired my design for a compound lever press. I to used tassie oak but from Mitre10 not bunnings. I ended up with an 11 times mechanical advantage so it works quite well. The good thing about this deign is that it is stable and compact. Mine is also designed to come apart but it looks good just as an item.
Please share some pictures. I always wanted to build this press, but put together a quick one and it works well enough, so it's still in the "holiday project queue" :)
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I made the press using a plastic mitre cutting box, a hand held circular saw and a drill press. It turned out ok but I was aiming more for function over looks. The tolerances could be better so I had to add a little bit of slack into the system. I think this press will last a while. I have also made a new pressing piece with smaller distances between the holes. The others were a bit far apart.
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Wow and WOW ! That looks familiar. Well done. I've been using mine for years and haven't had the need to alter the design apart from the weight application points. I have a 10 times and 12 times eyelet to get some knarly pressing weights. I also migrated away from milk cartons full of water to a series of gym disk weights.
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I just want to say thank you for this wonderful design. I finally built a prototype with cheap wood and it easily went under 810lbs theoretical force for 24h while pressing a cheddar.
Short story long I got in love with Andy's/awakephd's beautiful craftmanship and decided to build this press a long time ago. Sadly at some point I needed a press under short notice and put together a simple one with PVC that withstood 280 lbs which was enough for the cheeses I like to make, and is still going strong years later, so there was no reason to build this one.
Finally I found an excuse, as I am experimenting with Koji in cheese and wanted to make a cheddar subbing shio koji for dry salt... but that would take at least 600 lbs for the 6G make I do. At last I had a valid reason to build it! I made my plans, but was waiting to get a good bargain on hard maple or white oak, when I found myself with a "free weekend"... I didn't have the wood so I settled for going into Home Depot and getting whatever was available there (pine) to build a "prototype" that I would break but at least would get me ready to do the real thing later. I just used a coping handsaw, a hand sander, and a drill press, and honestly went through quickly as I was expecting to break it (e.g., I just sanded the joints I was going to glue not the whole thing). I built it with wood glue and dowels. It worked fine but the secondary lever burst open at 300 lbs... I built another one and the press went to 810lbs, which was enough for my needs. I've got them under that kind of pressure three times already with no issue.
So long story short, this design is GREAT. And I have a Frankenstein press that works so fine I don't know when I will find an excuse to finally build the "real" one and make it pretty :)
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Now I'm really blushing! :)
I build one of those presses and wondered about the 2 vertical spacers holding the pressing plunger in the middle.
In my logic they should amplify the horizontal movement of the plunger because they are very much at the top.
So I built it and did some testing without them and simulated them with 2 clamps holding wood in place.
As I thought it has way more wobble at the bottom with those spacers.
Basically now I will leave them away and have drilled way bigger holes in the plunger to allow movement in the holes and avoid even more wobble.
My pin holding it is 5.5mm and my holes in the plunger are 8mm.tested pressing a Kitchen towel roll and there's no noticeable wobble.
So my question is why are they even there? Majes no sense at all if the amplify wobble of the plunger.
Could it be nobody even thought about that since it has been posted? Or am I missing a point somehow?
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Ok, here's my finished Version of this press:
I built the press from Oak simce a woodworker told me thats the best to use. The bottom os Beech.
I bougt 22mm thick Oak planks and let them cut into 30mm strips.
Then I cut them in lengths and connected 3 of then for the maim frame stands using wood glue and dowels.
I tested it using the 5kg weight only and got 37kg to 50kg pressing power on low amplification setting depending on where on the arm I put it. So about 10times amplification.
On the highest amplification setting I got 137kg pressing power out of the 5kg when i put the weight close th the press. Didn't test the highest amplification at the outermost lever but should come close to 200kg there.
As weights I bought 0,5 / 1 / 2 / 5kg fitness weights. All combined it schon give me up tp about 300-350kg which I probably never need anyways.
Before this my first press was done using 2 wooden round kitchen boards where I drilled 3 holesand glued round wood poles in the bottom one so I could slide the top one which had bigger holes on top and put water buckets on it as weight.
But there I was pretty much limited to 2 water buckets so about 20-30kg.
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Good Morning,
I saw the compond-lever cheese press on Youtube. I was impressed with the design.
I would like to find the plans for the press. I have not found any on the internet.
My search brought me to this forum.
Are there plans available for the cheesepress?
In the older posts the pictures are no longer available.
Any help or advice would be appreciated.
Thanks
Neil
necron1@gmail.com
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Did these plans and pictures get posted anywhere? I’d also like to see them as I’d like to build a press with compound mechanical advantage.
Also is there a way that this forum could retain the photos and files uploaded?
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Email me at rwoodshop@hotmail.com and I will send you the plans.
Cheers
Bob Samuelson