7 ms·
Wringing
- lqet 7y agoIf you (like me) read the entire article without really getting an intuition for these "gauge blocks", here they are in action: https://www.youtube.com/watch?v=gbsd2OpPOMw https://www.youtube.com/watch?v=gbsd2OpPOMw https://www.youtube.com/watch?v=2lOOl3VxOtE https://www.youtube.com/watch?v=2lOOl3VxOtE
- leetbulb 7y agoI knew AvE's video would show up :D
- linsomniac 7y agoThe first is an AvE video, the one that introduced me to Wringing. There's also a Cody's Lab video where he sees if they will wring in a vacuum: https://www.youtube.com/watch?v=jNEvS_bjKIo https://www.youtube.com/watch?v=jNEvS_bjKIo (using AvE's blocks)
- jcims 7y agoFun video from Sixty Symbols explaining the underlying forces at work - https://www.youtube.com/watch?v=mgL_qH70KAU https://www.youtube.com/watch?v=mgL_qH70KAU
- nas 7y agoThis is a really nice video if you are interested in measurement precision for manufacturing: Machine Thinking: Origins of Precision and first project introduction https://youtu.be/gNRnrn5DE58 https://youtu.be/gNRnrn5DE58
- dugditches 7y agoWhile a lot of analog measurement tools have been replaced by digital ones, Gauge Blocks are still often used as the de facto reference(Though CMM machines[1] are becoming more and more common). You have a 'Master Set' of expensive Gauge Blocks that you use as a definite reference. Stacks of which can be combined with various tools for various purposes. https://i.ytimg.com/vi/2d-hGd_kYLc/maxresdefault.jpg https://i.ytimg.com/vi/2d-hGd_kYLc/maxresdefault.jpg https://images-na.ssl-images-amazon.com/images/I/61RhwssKaBL._SX425_.jpg https://images-na.ssl-images-amazon.com/images/I/61RhwssKaBL... https://i.ytimg.com/vi/n572qMo3g0A/maxresdefault.jpg https://i.ytimg.com/vi/n572qMo3g0A/maxresdefault.jpg The 1 Inch block always seems to go missing. [1] https://en.wikipedia.org/wiki/Coordinate-measuring_machine https://en.wikipedia.org/wiki/Coordinate-measuring_machine
- GrapeFriedNiggr 7y agoI love this guy's units. 1/4 of a bee's dick is my favorite.
- leetbulb 7y agoAlso: https://en.wikipedia.org/wiki/Cold_welding https://en.wikipedia.org/wiki/Cold_welding https://en.wikipedia.org/wiki/Optical_contact_bonding https://en.wikipedia.org/wiki/Optical_contact_bonding Super interesting stuff.
- idlewords 7y agoThis reminds me of a phenomenon called cold welding, where if the surfaces are flat and clean enough, the blocks of metal will fuse. Just touching two sufficienly thin gold wires will weld them. https://en.wikipedia.org/wiki/Cold_welding https://en.wikipedia.org/wiki/Cold_welding
- applecrazy 7y agoWho knew intermolecular forces could be so strong? This blew my mind.
- cryptonector 7y agoJohannes Diderik van der Waals!
- AnthonBerg 7y agoThis is such a beautiful HN post :) thanks!!
- TeMPOraL 7y agoI wonder how stable is such a "wring joint" over time and over mechanical stresses like temperature change and vibrations. Could you use this feature to e.g. attach stuff as a product assembly technique, as a temporary/non-destructively modifiable alternative to gluing or welding?
- greenyoda 7y agoThe joined blocks can be pulled apart with you hands. See the first video posted in this comment: https://news.ycombinator.com/item?id=20366089 https://news.ycombinator.com/item?id=20366089 So the bond is not comparable in strength to gluing or welding.
- TeMPOraL 7y agoI watched both. I know it's not comparable, but it seems plenty strong. In the case of the video, I'd guess if you'd double the contact surface, you could easily hang a coat on it. My question is, how long would the join last.
- stan_rogers 7y agoFor about as long as the parts on both sides of the join stay flat. And therein lies the rub. Permanent cold welding works just fine on small contact areas, but on anything large you're at the mercy of thermal movement, etc. How much can that be? Quite a bit, actually [1]. That's just breathing on a braced precision straightedge, and the difference in temperature across the piece is easily measurable. [1]https://youtu.be/UG6LV8v8W-0?t=1922 https://youtu.be/UG6LV8v8W-0?t=1922
- jcims 7y agoFWIW the Starret tips on maintaining gauge blocks says not to leave them wrung overnight.
- stan_rogers 7y agoSee "cold welding". As far as actual gauge blocks go, they're relatively easy to separate by sliding after you're done with your measurement or set-up. (Good Jo blocks are horrendously expensive. You wouldn't want them to be single-use items.)
- ndespres 7y agoIf you're interested in how gauge blocks fit into the history of precision engineering, a new book called "The Perfectionists: How Precision Engineers Created the Modern World" puts them into context, and presents a very interesting perspective on the events and developments that brought us into modernity. These blocks feature strongly into the industrial revolution. I strongly recommend the book! https://books.google.com/books?isbn=0062652575 https://books.google.com/books?isbn=0062652575
- war1025 7y agoI saw this book at the bookstore precisely one time. Made a note to look into it in the near future. And then was never able to find it again. Will have to look a bit harder maybe.
- russdill 7y agoOr for the lazy, here's Destin https://www.youtube.com/watch?v=T-xMCFOwllE https://www.youtube.com/watch?v=T-xMCFOwllE
- DonHopkins 7y agoFlat suction cups.
- newnewpdro 7y agoYep, that's what I always thought was the mechanism behind this action. Separating such precisely contacting surfaces creates vacuum, resisting the separating force.
- NickNameNick 7y agoThe Cody's lab video linked above demonstrates that they don't fall apart in a vacuum.
- Bizarro 7y agoGreat stuff. We need more of these types of science tidbits on HN. And good links by the commenters too. I love Feynman's classic style of "explaining to a 5 year old" on Cold Welding. The reason for this unexpected behavior is that when the atoms in contact are all of the same kind, there is no way for the atoms to “know” that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin surface layers of contaminants in between, the atoms “know” when they are not on the same part. — Richard Feynman, The Feynman Lectures, 12–2 Friction
- rkagerer 7y agoHere's one I posted today showing how tunnel boring machines work. More civil engineering than science, but I found it quite fascinating: https://news.ycombinator.com/item?id=20364474 https://news.ycombinator.com/item?id=20364474
- dang 7y agoWe've put that in the second-chance pool (described at https://news.ycombinator.com/item?id=11662380 https://news.ycombinator.com/item?id=11662380) so it will get a random placement on the front page.
- hwillis 7y agoNote that this is a big oversimplification- it doesn't apply to gage blocks. Cold welding and similar phenomenon can only truly happen with metallic bonds and very large grain sizes. Non-metallic bonds are structured and require precise orientations and conditions to reform. Metals are still structured -metals have crystal grains- and the microscale structure needs to line up in order to reform. In cold welding, you force that to happen with high pressures. This doesn't really apply to gage blocks because tool steel has passivated surface oxides and complex crystal structures. There are very few metallic bonds exposed on its surface. It also has very nasty, often needle-like grains. There's no chance that the metal atoms are being attracted to each other. Not to mention that wringing works with ceramic gage blocks as well. It is probably a complicated combination of effects. Adhesion (intermolecular forces) probably plays a minor effect at small regions where the surfaces are extremely close together. Casimir forces probably have an effect on most of the surface. Small amounts of grease probably form much stronger adhesions by "carrying" the forces between the surface oxides. Vacuum being trapped by grease probably plays a fairly large part in rougher blocks wringing in an atmosphere. Adhesion and Casimir forces are not well understood.
- kohtatsu 7y agoI feel like the article is missing a section on uses. Is it strictly measurement?
- jcims 7y agoYou can use them in concert with a Sine bar to create precise angles https://en.wikipedia.org/wiki/Sine_bar https://en.wikipedia.org/wiki/Sine_bar
- lightbulbjim 7y agoSine bar in action: https://www.youtube.com/watch?v=PO-Ab7YfBzY https://www.youtube.com/watch?v=PO-Ab7YfBzY
- jacobolus 7y agoCheck out this alternative version of a sine bar https://observablehq.com/@jrus/sinebar https://observablehq.com/@jrus/sinebar Also includes some nice youtube videos inline for context.
- scottlocklin 7y agoGuage blocks are for measuring things. The "wringing" thing has been used in optics for precision alignment for centuries, though nobody calls it that.
- Gracana 7y agoThey're most often used as measurement references. You inspect parts on a surface plate (table or block that's very flat) using a dial test indicator on a rigid base that can be slid around. The indicator has a very short range of measurement (say, 0.01" for an indicator with 0.0001" graduations), so to inspect a part surface that's supposed to be 1", you'd wring together a 1" stack of gauge blocks on the surface plate, adjust your indicator up or down on the base so that its probe is in the middle of its travel on top of the stack, and zero the indicator face. Now you can measure 0.9950-1.0050"... just slide the indicator stand to your part and sweep the indicator probe along its surface to measure.
- kashishhora 7y agoThere's a great Sixty Symbols video about gauge blocks and how they work: https://www.youtube.com/watch?v=mgL_qH70KAU https://www.youtube.com/watch?v=mgL_qH70KAU
- nateburke 7y agoThis is part of the reason why you commonly see cymbal players in orchestras use an oblique motion for a crash rather than a head-on direct motion. Bringing two symbols together directly along their axis of rotation risks getting them stuck together like suction cups--the crazy part is that even when holes are drilled to release the near vaccum between two stuck cymbals, they remain glued together by the forces described in this article.
- mrob 7y agoAre you sure that's not just the air pressure difference? Cymbals often have a shape with many concentric ripples, so you might need multiple holes to equalize the air pressure between each ripple. Wringing only works with extremely flat surfaces, and it works even in vacuum.
- defterGoose 7y agoYep, admit I was a little taken aback after the drilled holes explanation. This seems correct, as no practically priced cymbal could be so precisely made.
- emmelaich 7y agoI don't think they need to be precise; any reduction in the natural vibration can be detrimental to the sound. They never get "stuck" together, however, imnsho.
- defterGoose 7y agoYeah, I was saying that getting the surfaces to adhere sans vacuum seems unlikely for such an imprecise object
- cmroanirgo 7y agoI was wondering about (what I presume to be) this effect the other day with regard to things sticking to my bench top that I hadn't moved in a few weeks. One was a glass jar and the other a plastic lid. The bench is oiled hardwood. I was thinking that it seemed related to the two coefficients of friction (static vs moving). That is, the static part of friction could well be this phenomena on a less sticky scale. My thoughts led me to how it could be an electron transfer going on that bonded the two materials on some way... (This was all backyard conjecture of course) So, many thanks for this post: it shows how much better thought has gone into the problem.
- nmstoker 7y agoEdit: Oops - somehow missed the other post mentioning this book. Sorry! These are covered with a charming personal story by Simon Winchester in his book The Perfectionists: How Precision Engineers Created the Modern World It's reviewed here: https://bookmarks.reviews/reviews/the-perfectionists-how-precision-engineers-created-the-modern-world/ https://bookmarks.reviews/reviews/the-perfectionists-how-pre... and the audiobook as pretty good too.
- narrator 7y agoIs this the Casimir effect? https://en.wikipedia.org/wiki/Casimir_effect https://en.wikipedia.org/wiki/Casimir_effect
- hwillis 7y agoCasimir forces are probably involved- gage blocks work with flatness/separation (tens of nanometers) that is too high for intermolecular attraction (hundreds of picometers). Casimir attraction works at longer distances, but it's far from well understood. It's most likely a combination of all the common guesses, although the air pressure one is pretty weak.
- pard68 7y agoI grew up next to an abandoned granite quarry. You could, and still can --though they are beginning rarer as the quarry is a bit of a tourist attraction, find super smooth, polished rocks. We would do this wringing with them all the time as kids. Never over until now did I wonder if anyone else had ever done this or if it had a proper name.
- defterGoose 7y agoReally? It seems unlikely to find ones flat enough in such a non-precision environment to exhibit the same behavior. Maybe they were flat enough and cupped so that you could create a slight vacuum like you can with the palms of your hands? Would love a picture if you could get one.
- pard68 7y agoI believe that the difference is our stones were wet. But also, very smooth. The blocks ship with one side polished smooth. Still being wet probabny helped.
- microcolonel 7y agoI suspect OP was brought here by this excellent video which enjoyed some success over the past couple days on the topic of flatness. https://youtu.be/OWa3F4bKJsE https://youtu.be/OWa3F4bKJsE
- ryansmccoy 7y agohttps://www.youtube.com/watch?v=2lOOl3VxOtE https://www.youtube.com/watch?v=2lOOl3VxOtE <- Video Explanation
- robocat 7y agoTo play with this effect yourself: 1. pull apart an old multi-platter hard drive 2. Take the platters out The platters are very flat, and they stick together remarkably well without any liquid between the surfaces. Specks of dust will stop them sticking together so well. Be careful not to breath in any dust (or eat anything!) from the drive, as they do contain some exciting elements.
- mietek 7y ago> Be careful not to breath in any dust (or eat anything!) from the drive, as they do contain some exciting elements. Can you expand on this? Which elements?
- sgnelson 7y agoAlmost all you'll ever need to know about gauge blocks [1]. It's also a fairly decent introduction to the uncertainties of measurements, and other factors of taking measurements of objects. Of course it also includes a section on wringing. (and other sources on papers about the wringing phenomenon) [1] https://www.nist.gov/sites/default/files/documents/calibrations/mono180.pdf https://www.nist.gov/sites/default/files/documents/calibrati... Further more, if you're really interested in how modern precision engineering/industrial manufacturing came to be; I highly highly recommend you look into Foundations of Mechanical Accuracy by Moore. (it's a $150 book, pdf easily found by googling.) (I'm a flatness/metrology nerd. I recently lapped three cast iron plates together just because I wanted to create as flat a surface as I could. Just because. )
- ChainOfFools 7y agowhat would you consider to be the flattest off the shelf metal commodity component available today, would it be a typical hard drive platter or something else?
- userbinator 7y agoYou can see a similar effect with ordinary glass plates --- the production process[1] is such that it normally has a flat enough surface that two pieces will naturally "stick" together if placed upon each other and there's nothing else between. [1] https://en.wikipedia.org/wiki/Float_glass https://en.wikipedia.org/wiki/Float_glass
- dredmorbius 7y agoThe manufacture process is fascinating: https://youtube.com/watch?v=ig4G5WbOMLc https://youtube.com/watch?v=ig4G5WbOMLc
- emmelaich 7y agoAt our physics school we had some super flat metal blocks. Much flatter than gage blocks. We were warned never to put them together or we'd never get them apart. These blocks were used for measurement, but I can't remember exactly how.
- mveety 7y agoThey’re probably surface plates. They’re used as a flat reference for measurement.
- Waterluvian 7y agoThis got me wondering, (and I know it's probably not a physics question). If I scrape two fingers and press them together for a week. How do the skin cells know which other cells to attach to when healing? Or will I have one super finger?
- jacobsimon 7y agoTry it and let us know!
- graphpapa 7y agoThis is the origin of the concept of a skin graft, surely.
- benj111 7y agoThat's how it works basically yes. https://www.royalfree.nhs.uk/services/services-a-z/plastic-surgery/facial-reconstruction-and-face-transplants/history-of-plastic-surgery/ https://www.royalfree.nhs.uk/services/services-a-z/plastic-s...
- hanniabu 7y agoThey can grow together but will take longer than a week. There's a man the had his hand degloved and they sewed it into his stomach to heal, after which they cut his hand back out and used his stomach skin to wrap around and reshape some resemblance of a hand. Example 1: https://www.thesun.co.uk/news/4303135/surgeons-save-hand-sewing-into-stomach/ https://www.thesun.co.uk/news/4303135/surgeons-save-hand-sew... Example 2: https://www.menshealth.com/health/a19517212/carlos-mariotti-mitten-hand-surgery-mangled/ https://www.menshealth.com/health/a19517212/carlos-mariotti-...
- winrid 7y agoWow. Can you imagine how that would feel, to have your hand inside of you? I'd worry about accidentally breaking something inside me. Amazing though.
- JackFr 7y agoThis takes me back to a summer job I had 35 years ago, calibrating a set of gauge pins. I think it was a couple hundred of them. Visually inspect them for corrosion or scratches, wipe them down with WD-40, measure each end and the middle with digital calipers, and log the measurements and any comment on their appearance. Honestly it probably to0k 2.5 days but it felt like forever.
- someexgamedev 7y agoIs this what makes clear plastic card sleeves stick together? I always figured it was static electricity but maybe it's this?
- superjan 7y agoIsn’t this the same effect as the screen protectors we all have on our phones?