Understand 1,700 Mechanical Linkages with These Helpful Animations | Hacker News Reader

Understand 1,700 Mechanical Linkages with These Helpful Animations

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315 pointsadamnemecek65 comments

For those interested in these kind of mechanical things, Dover has republished some 19th and early 20th century public domain books that collected together mechanical movements. Some examples:

"507 Mechanical Movements: Mechanisms and Devices" by Henry T. Brown, from 1868: http://www.amazon.com/507-Mechanical-Movements-Mechanisms-De...

"1800 Mechanical Movements, Devices and Appliances" by Gardner D. Hiscox, first published in 1899. This is the 16th edition from 1921: http://www.amazon.com/Mechanical-Movements-Devices-Appliance...

There is also a website that has all the illustrations and text from the Brown book, and has added animated versions of many of them: http://507movements.com/about.html

Since both of these are in the public domain, you can legally print your own copy, which is more convenient for some people.

Google Books has scanned the 507 Mechanical Movements book, although their search engine is terrible at finding things like that on their own site; one copy is available from http://www.pdnotebook.com/wp-content/themes/thesis_16/custom.... The other, longer book is harder to find via HTTP, although Libgen has a scan of the 2007 reprint. Timothy Schmidt scanned the original 1899 edition in 2008 and uploaded it to The Pirate Bay, which seems to not have it now: http://builders.reprap.org/2008/12/1800-mechanical-movements....

US patents are also a wonderful source of public-domain diagrams of machinery, and they are generally better explained (especially before about the 1980s, at which point their writing quality took a nosedive and they descended into nearly-unreadable jargon) but I'm not aware of an easily downloadable repository of scanned patents.

Looks like you can get "1800 Mechanical Movements, Devices and Appliances" by Gardner D. Hiscox at:

http://www.pdfarchive.info/pdf/H/Hi/Hiscox_Gardner_Dexter_-_...

Thank you very much! What search engines do you use?

Just found it using Google. I think I had to end up quoting various parts of the title, adding "PDF" as part of the search, and going past the first couple of pages of search results.

Or, if you want, you can go straight to Prof. Nguyễn's youtube channel: https://www.youtube.com/user/thang010146/videos?sort=p&view=...

Amazing. Now I'm left to wonder what all these contraptions are good for. For example, why would one use something like this "Persian joint": https://www.youtube.com/watch?v=mFoiSRWdW5E ?

High intersection angle CV joints. Similar in purpose to the joints between the driven wheels and power plant (transmission/transaxle/rear diff/whatever) in your car, but Persian joints can tolerate much steeper angles.

Some time ago i talked with a machine designer - and he told me that the industry is moving away from complex mechanical contraptions , into microcontrolers coupled with smart motors(servo - either linear or rotary) which allow exact controlled positioning.

This is certainly true in general. I see a niche for the mechanical solution if reliability is a primary goal and there is a (not too complex) gear that can solve your problem.

About ten year ago I worked in project that designed a solar tracker. These trackers need to be cheap and reliable. Every hour an mechanic spends in a remote location is incredibly expensive and cuts into your yield very fast.

Interestingly there is a gear that can follow the path of the sun very well while being driven by motor with constant speed [1].

[1] https://www.youtube.com/watch?v=2NGSL--PmGY

Why are mechanical solutions more reliable than a servo ? Aren't mechanical and moving parts less reliable than electronics , in general ?

    Aren't mechanical and moving parts less reliable than 
    electronics, in general?

I don't dare to answer this in general, maybe someone more knowledgeable can offer his or her opinion. In our case the alternatives were:

  1. Simple gear and constant velocity three-phase motor[1]
  2. Two axis mounting and two stepper motors.

First option has less parts and should be more reliable in theory. That being said: I only know of commercially available solutions of the second kind. Maybe this has changed in the last ten years, but our solution never made it to market.

[1] Industrial three-phase motors are real workhorses, produced in large quantities since ages, relatively cheap and incredibly reliable.

You can think of a mechanical solution as a straight line program with no conditionals. The servo solution has a feedback loop that will ultimately face an upset in the feedback loop, a broken sensor, worn brushes on the servo motor, over heated power transistors, etc. Both solutions will suffer from fatigue in the long term, but an active solution with electronics and a servo will suffer from a element failing and possibly causing the active solution to destroy itself.

I was hoping that footnote was a link to the gear, not a demo of its application. Would you happen to have that?

I'm sorry, here is the patent[1].

EDIT: I almost forgot that my old website had a page about a model I built back then. I never migrated it to the new site but it is still available[2].

[1] https://www.google.com/patents/US4585318?dq=inassignee:%22Di...

[2] http://weinzierl.name/2006/en/miniviax

Except for the mechanical watch industry; which might make a serious comeback? I mean it's still here, but interest has faded. I have weird feeling people will become interested, beyond a steampunk level, in finely machined/designed mechanical watch movements?

The Internet has made watchmaking/repair something a determined person can learn at home. I guarantee once you learn the basics, you will look at that old Seamaster sitting in the drawer in a whole new light. Taking apart an old watch, cleaning it, oiling it, and eventually wearing it on your wrist is a good feeling.

With me it went from an interest in automatic movements, to a hobby. Then it went to an obsession, but I'm weird? (I take things to far.) To maybe a building my own watch one day? I haven't lost money on the pursuit of this hobby though.

If you are young, their are a few watch repair schools still around. Rolex funds many of them because so many watch repairers are retiring, or died years ago. I would definetly go to one of these schools if I was younger, and could just pick up and move. That said, the right use of the Internet, and the right books can get someone pretty proficient in repair, and even design?

Think about all those rich dudes who wear complicated mechanical timepieces? All those watches will eventually need servicing? I've noticed rich poeple like a good deal, and take notice of watch servicing costs(cleaning, oiling, etc.) that are currently outrageous at the factory. I feel if a future watchmaker has the right tools, a portable clean room, and charged under $300 a service, he/she could make a good living?

It does seem like an uphill battle to get people interested in watches? When I was younger, I just liked what the watch looked like. My first watch was a Tag Formula 1 bought across from Macy's in San Francisco in the 90's. I like that Quartz watch. As I got older, I started to appreciate what's under the hood, and I really wanted to learn how to repair these mecanical complications. I can guarantee it's not as hard as some people make it out to be! I hope to have a few free instructional websites up in the future.

I used to be very interested in these. I really enjoyed learning about the various movements, servicing them, etc. When in college I worked to be able to buy a couple nice automatic watches and have always appreciated them. They're absolutely fascinating. But I kind of fell out of interest in favor of digital watches years ago. Love smart watches like the Basis and Pebble as they're like an extension of my phone. My old Tag and IWC have been sitting in a drawer for years and I'm torn between selling them for the thousands they're worth, or keeping them around in case I get interested again.

I think the age of passing down watches to your kids is over and generally they're simply status symbols,whereas before they were status symbols that served a useful function (that's now replaced with our phones).

One would be able to make a living learning to service expensive mechanical watches, but the industry seems to be dying and I'm reasonably confident it won't make a resurgence among the general population.

Obsolete technologies become forms of art.

(Art is also the earliest adopter of new tech.)

I think this is because manufacturing a copy of a software contraption is a lot easier than manufacturing a copy of a hardware contraption. But maybe automated fabrication can change that.

It's a constant velocity joint. Like the one that lets you turn the wheel on your front wheel drive car.

Agreed, a brief note on application would be great.

Transmission like this looks really good in a simulation, but I wonder how much lubrication would this require to operate in the real world.

this: https://www.youtube.com/watch?v=NdzSqc8pxVg

A lot of those solutions have been around for centuries but are quite impractical. The problems are often the required operational tolerances, wear rate, poor torque characteristics and other real life issues.

They are utterly fascinating to watch though.

Someone else made an animation of this in r/mechanicalgifs not long ago, and people brought up the same objection. It turns out, though, that you can buy angled screwdrivers using this mechanism, and they work pretty well.

Mechanical linkages are fun. There's a nice collection of them at the Museum of Science and Industry in Chicago, left over from the 1933 Century of Progress Exhibition. I used to have a Russian textbook on mechanism design with over a thousand of them. It was all drawings; you didn't really need a translation.

This guy must really like spending time in Autodesk Inventor. (I just spent an evening getting some robot parts to fit in there. I'll machine them on a CNC mill on Monday, and they will fit. Which is the whole point of Inventor.)

Do you remember the name of the Russian book?

Is there a name for the field of computer science that classifies these linkages by their topological proporties other than just general CAD stuff? It would be awesome to say I have linkage A and linkage C, what kind of linkage B can I put in the middle?

Yes, there is: "kinematic synthesis." It is not typically considered a "computer science" topic; it is instead taught in various forms in mechanical engineering curriculums.

Can you recommend any good books on kinematic synthesis?

These are amazing !

I already have a use for the limited space door at home, and I want to build the Archimedian Drive just because it is beautiful.

This also says something to me about the value of human determination - a retired professor in Vietnam must be old enough to have been an adult during the American involvement in their wars, and crushing poverty their state was left in, still a professorship and a desire to teach the world is left.

Hats off indeed

I really don't want this comment to go somewhere weird, but... I think the experience of war sharpens the desire to see the world made a better place. Most people come out of the darkness of war and see the value of life, and this often permeates their attitude in how they want to leave the world. I think war brings out the altruism in people.

Let's hope education about previous wars can have the same effect. War docos make me feel very fortunate and grateful and not at all complacent. A good war doco takes you to a dark place, some have left me shaking my head in disbelief and reflecting a lot.

But anyway, how about that rack and pinion animation! Finally I get why it's so effective at safely pulling an old steam train up a steep slope. I honestly was foggy on how the continuous engine motion translated into alternating cycles of locking and linear motion. So simple though.

> Let's hope education about previous wars can have the same effect. War docos make me feel very fortunate and grateful and not at all complacent. A good war doco takes you to a dark place, some have left me shaking my head in disbelief and reflecting a lot.

Not a war docu, but still eye opening. A 1969 documentary about a boy leaving his hair-dressing apprenticeship to join the British army.

http://www.bbc.co.uk/programmes/p00jrhv0

> First transmitted in 1968, documentary following Martin May, an apprentice ladies hairdresser, who decides to join 'a man's world' - the Junior Leaders Regiment of the Royal Armoured Corps. The programme follows him as he begins his training with a group of recruits.

This boy, Martin May, is only 15 when he joins.

(I have no idea if BBC iPlayer programmes are viewable outside the UK. There's probably some method to do so).

Thx for link. Yes anyone who gives in to geo-blocking these days is a bit behind the times!

Loosely relevant, my deskmate and his family escaped Vietnam at about 16 or 17 around '76 or so, on a crowded fishing boat to Thailand. He and his siblings and cousins all made good lives in America.

I was in the Navy when my ship picked up some refugees in a scary boat, around '77. After the rescue we sunk the boat (navigation hazard) with the forward gun.

The American company I work for now does business in Vietnam (and the rest of the world).

The world turns. Today I hope for good things to come for the people of Iran and Cuba, and at least a peaceful working relationship between those countries and America.

Very cool. I have been building animatronics and mechanisms for years until the last 5 years or so. Typically I relied on old classics of mechanisms, and then I would model it in Inventor (now Fusion 360 or FreeCAD lately), to see how it worked. These are brilliant and so numerous! My hat off to Prof. Nguyễn!

This is amazing, like a code repo for mechanical programming. You have a number of common libraries here such as planetary clutches, along with a variety of solutions to common problems like how to convert between straight and circular motion.

In fact just like in coding where you have common issues like how to do an associative array, you have common issues in mech like how do I keep something pointing the same direction.

Unfortunately this isn't the code repo, or even a compiled executable, just screenshots of the executables.

Incredible timing. Just yesterday while looking at a door opening mechanism, I was just wondering where I could find something like this.

Also of potential interest is Chebyshev's "paradoxical" 6-bar linkage:

http://www.etudes.ru/en/etudes/paradox/

If I remember the catalog correctly, there are a number of Chebyshev linkages among Prof. Nguyen's videos, such as https://www.youtube.com/watch?v=xPVcL0fMBCk. I haven't found the paradoxical 6-bar linkage, though.

My guess is that basic linkages like this are not patentable, even if you invent a "new" one. That could be an argument in support of not allowing patents for at least the fundamentals of computer science and programming.

Do you have any evidence to support this or is it just your reckons?

Just my reckons.

I would have preferred if these were looping GIFs, or if there was a way to watch these videos on loop without interruptions. There was a similar site that had looped animation for a lot of these.

On the youtube page if you're using the HTML5 player, you can make them loop at least in chrome. Just right click the video, which should bring up the youtube menu. Just right-click again in the video area (not on their popup menu, but while it's still up), and "Loop" should be an option.

You can use gfycat for this. I converted the first one to demo: https://gfycat.com/CornyHonorableFrillneckedlizard.

Should be very easy to do, although you'll lose metadata and potential credits, of course.

I wonder how much time he spent on these. Incredible dedication!

Very cool, no Theo Jansen linkage in it however.

Pay attention. If you ever get sent back in time, this information will be important. You can make a fortune with this and the ability to create a solar oven to boil sea salt for salt (that's the seed money right there).

Wouldn't it be easier to make the fortune with the time machine I already have in this hypothetical scenario :-)?

Not all time travel scenarios leave you with a time machine. The machine might itself be trapped in a closed time-like loop, could have a fixed end-point.

A Connecticut Yankee in King Arthur's Court is a classic example.

It would actually be a time-space machine if you didn't plan on suffocating.

http://i.imgur.com/o4CJS2w.png

The Sun is the center of the Universe. Interesting.

Everywhere is the center of the Universe.

That doesn't make much sense. There's no absolute "space" coordinates. Why would a time machine pick some random frame of reference instead of yours? I suppose you're correct, in a tautological sense.

I prefer to remember "75% saltpeter, 12.5% charcoal, 12.5% sulfur" for those pesky traveled-back-to-Medieval-Times situations.

Have you learned to identify saltpeter or corn gunpowder? I understand that those two are problems of their own.

Ok...That's pretty cool. Thx :)

Seeing this leaves me incredibly dissatisfied with the state of Wikipedia. This is what it should be about. Using rich media to explain and fascinate. Instead we get 10.000 words on the history of Anime.

You mean like these? https://commons.wikimedia.org/wiki/Category:Animations_of_ma...

You have to remember that anyone can write (maybe not write well, but can write). Not too many people can use AutoCAD and ever fewer have enough knowledge to be pumping out one a day like this guy.

Imagine if wiki spent their money on building tools to allow people to create multimedia content for the site.

AutoCAD models are an extreme case, but how about a tool to make quick vector drawings, or a tool to make flow charts to explain complex concepts. All right there in the wiki interface. All super easy to use. 10x-ing content creation.

Your Anime example presents a problem. Anime can't be whipped up quickly with such tools, or it would be low quality.

And to get past the rights issues with including fine examples of Anime on Wikipedia, would be an uphill battle.

I sort of understand what you're saying, but Wikipedia is only part of the puzzle of information. That's why we have the "Internet"!

It's perfectly fine to link out to Youtube videos or channels from a Wikipedia page about mechanical systems or CAD specific topics.

I, too, would like to see Wikipedia expand its abilities to present animations of mechanical machinery. We need to recruit and retain awesome contributors like Prof. Nguyen, and we have social problems that currently make that difficult. However, I don't think that reducing our anime coverage would help us toward that goal.

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