6 ms·
How a differential gear works (1937) [video]
- analog31 12y agoExcellent use of graphics, created in the age before computer graphics.
- hughlomas 12y agoA World War 2 training video for evading flak cannon fire is one of the best examples of graphical information presentation that I've seen. https://www.youtube.com/watch?v=qP_-WUMi-nw https://www.youtube.com/watch?v=qP_-WUMi-nw It features smoothly animated and highly functional designs as well as overlaying graphics on real footage to achieve a fashion of "augmented reality". The production quality is astounding and it is amazing to think that it was produced in the 40s. The entire video is an inspiring example of conveying information.
- joshontheweb 12y agoThat was really interesting. I never knew there was this kind of strategy behind flak evasion. Man, must have taken some stones to do a bomber mission. I knew an old timer that flew bombers in WW2 and he said towards the end of the war the germans were running out of metal and all sorts of things were used as flak. He said nuts and bolts were pretty common. He'd find them embedded inside the cabin after close flak fire. Pretty scary to think that your end might come from a washer.
- DanBC 12y agoRAF Bomber Command had appalling rates of attrition through WWII. http://en.m.wikipedia.org/wiki/RAF_Bomber_Command http://en.m.wikipedia.org/wiki/RAF_Bomber_Command The wiki article gives good explanation of how bombing developed during WWII - starting as a weapon to terrible to be used (based on poor quality data); with general agreements not to kill civilians; realising that bombers were hopelessly inaccurate; changing tactics to allow bombing of civillian populations, including the (to my mind) war crimes of fire bombing. > Bomber Command crews also suffered an extremely high casualty rate: 55,573 killed out of a total of 125,000 aircrew (a 44.4% death rate), a further 8,403 were wounded in action and 9,838 became prisoners of war. That's pretty much "toss a coin".
- jonesdc 12y agoThank you for posting this.
- Animats 12y agoWe know. I put a link to that video (to the Internet Archive, not YouTube) on Wikipedia years ago. There's a whole series of Chevrolet films from the Jam Handy organization at the Internet Archive. "Take it Easy", "Spring Harmony" and "Shockproof" cover how auto suspensions work. "Facts on Friction", "Hydraulics" and "What stops them" explain brakes. "Head on" and "No Ghosts" - auto frames. "Water Boy" - cooling. "Free Air" - carburetor. There's more.
- cipherzero 12y agoI had never seen this, so i appreciate the link. Is there any similar video for a limited slip differential?
- function_seven 12y agoHere's a good start. Alter search query to taste. https://archive.org/search.php?query=creator%3A%22Handy%20%28Jam%29%20Organization%22%20suspension https://archive.org/search.php?query=creator%3A%22Handy%20%2...
- spiritplumber 12y agoIf you like videos like this, check out Retrotechtacular on Hackaday. They have a series on mechanical firing computers on navy ship that is nothing short of mech-eng porn, and I mean the classy kind.
- k2enemy 12y agoThat was amazing, thanks. I found the integrator and multiplier especially simple and clever. Here is a link to a youtube playlist: https://www.youtube.com/user/navyreviewer/videos?query=mechanical+computer https://www.youtube.com/user/navyreviewer/videos?query=mecha...
- rootbear 12y agoI watched that whole series a year ago and was fascinated. I believe it has been posted here before but it's worth repeating.
- leeoniya 12y agosome may also enjoy a 3d-printed triple gear https://www.youtube.com/watch?v=I9IBQVHFeQs https://www.youtube.com/watch?v=I9IBQVHFeQs
- wmeredith 12y agoDoes this have any possible practical applications? Or is it just cool?
- nopar8 12y agoThe way the teaching was sequential really made it an understandable to a layman like myself.
- joeblau 12y agoDifferential -- the most misused word in sports. The video is a great explanation about the automobile version.
- franciscop 12y agoIt is just too awkward that I learned how they work with the same video last year, still better than my University's current presentations
- sreejithr 12y agoI'd have loved it if these guys had made a video on fly wheels. Dying to know more about those.
- mutagen 12y agoNice to follow that with this short video illustrating how one type of locking differential works to eliminate some of the disadvantages of an open differential. https://www.youtube.com/watch?v=MCxqUJCZGNU https://www.youtube.com/watch?v=MCxqUJCZGNU
- pkulak 12y agoSo, one wheel starts spinning, and then, at a certain speed, it gets immediately locked into the other wheel which isn't moving at all? How does that not blow up the entire differential?
- draker 12y agoFor manually operated lockers the axle shafts have to be moving at the same speed or with very little difference in speed to be engaged. >Only engage the Eaton ELocker™ differential while the vehicle is stationary or operating at speeds of 3 mph or less with minimal wheel slippage. This specific locker (Eaton G80) is self-engaging up to a set speed which is intended to prevent this from happening, though it has been known to occur. >The G80 can be very effective when used within its limitations. However its very design can lead it to failure. It requires a certain amount of speed difference between both rear wheels to operate. Basically more slip than you would ever encounter going around a turn, but it will not lock at speeds above roughly 20-30mph. This it where it earned the name "gov-lock". It has a speed governor that operates off centrifugal force inside to govern locking. When it locks, it locks hard. Imagine one tire sitting still, and suddenly being launched to a speed of 20-25mph. That takes a great deal of force and puts a lot of strain on internals. They have a tendency to break with no warning. Page also has photos of one that has failed. http://www.ar15.com/forums/t_1_134/1250761_g80_differential__tell_me_about_them.html http://www.ar15.com/forums/t_1_134/1250761_g80_differential_...
- bri3d 12y agoWith a hard-locking differential ("lockers", generally used off-road), engagement while one wheel is spinning is ill-advised. They're generally toggled on at low/zero speed by the operator in anticipation of a traction-loss situation. The variety of differential which does not immediately lock one wheel into another is http://en.wikipedia.org/wiki/Limited-slip_differential http://en.wikipedia.org/wiki/Limited-slip_differential .
- journeeman 12y agoWow, that was a fantastic video. I could understand it easily only because they iteratively added complexity to the models. It's amazing how well they have made the tutorial for the layman. Thanks a lot for sharing.
- wickawic 12y agoIf you liked that, you might like this similar video about how a mechanical watch works: http://www.youtube.com/watch?feature=player_detailpage&v=508-rmdY4jQ#t=315 http://www.youtube.com/watch?feature=player_detailpage&v=508...
- journeeman 12y agoEnjoyed watching it. Thanks. :-)
- hsshah 12y agoI remember seeing this a while back and realizing I learned more from this video than I learned in class during my college course. Amazing production value. We should properly catalog such gems so that students and even professors can use these to teach (instead of attempting to reinvent the wheel)
- charlysisto 12y agoI was generally not bad at physics but I remember not getting my head around this one... What a great lesson for decoupling systems. I wonder what's the software equivalent in design pattern land. The facade maybe ?
- noblethrasher 12y agoNot sure about a corresponding design pattern, but the content neatly maps (no pun intended) to function composition.
- tapatio 12y agoI never really got my head around electricity and magnetism. That stuff is very abstract.
- thebladerunner 12y agoInteresting
- thebladerunner 12y agoInteresting
- thebladerunner 12y agoInteresting
- reckoner13 12y agoMy favorite: Wave Behavior from Bell Labs: https://www.youtube.com/watch?v=DovunOxlY1k https://www.youtube.com/watch?v=DovunOxlY1k
- bithush 12y agoI use this video quite often to show an example of one of the best educational videos I have ever seen. The language, presentation, use of graphics (impressive for the time) and demonstrations is just superb.
- JasuM 12y agoAn interesting mechanism using differential gears, doubling the speed while only using gears of the same size: http://507movements.com/mm_226.html http://507movements.com/mm_226.html
- rahulmax 12y agoWow! Amazing. There's another video from 1949 about 'How a Watch Works' — http://www.youtube.com/watch?v=508-rmdY4jQ http://www.youtube.com/watch?v=508-rmdY4jQ
- gradstudent 12y ago@edferda: props for posting this; the pedagogy here is just terrific!
- deleted 12y ago[deleted]
- spacefight 12y agoBest spent 8minutes today, thanks!
- petercooper 12y agoThere's a chap who collects tons of videos like this on YouTube. He was mentioned on MetaFilter the other day: http://www.metafilter.com/143903/Do-you-like-vintage-training-educational-fims-Meet-Jeff-Quitney http://www.metafilter.com/143903/Do-you-like-vintage-trainin... Or you can find his channel direct on https://www.youtube.com/user/webdev17/videos https://www.youtube.com/user/webdev17/videos
- __database__ 12y agoAmazing!
- mxfh 12y agoAround the Corner (1937) Producer: Handy (Jam) Organization ☞ Sponsor: Chevrolet Division, General Motors Corporation Probably the source of this re-encode, with significantly less artifacts, on archive.org: https://archive.org/details/Aroundth1937 https://archive.org/details/Aroundth1937 ☞ Named after Jam Handy: https://en.wikipedia.org/wiki/Jam_Handy https://en.wikipedia.org/wiki/Jam_Handy
- haphazardeous 12y agoBrilliant video. It's definitely a lot better to see the basic principles and evolution of those principles in action.
- VLM 12y agoI'd like to see a Torsen gearcase. Strange little things, they look like pepper grinders.
- smilefreak 12y agoI guessed some of the next steps, and considering I have the automobilic knowledge of the ancient greeks, that was pretty impressive. An education in how to present to a lay audience.
- draker 12y agoI had not seen this particular video but have seen the "How a manual transmission works" from the same series. https://www.youtube.com/watch?v=aAWxZRuBXtw https://www.youtube.com/watch?v=aAWxZRuBXtw
- jonmrodriguez 12y agoIs it possible to create a "negative differential gear" that puts more torque into the wheel that is stuck? (in the hopes of forcing it unstuck)
- birdmanjeremy 12y agoYes. You are referring to a locking differential, of which there are several types. Some use clutch plates, and will work even if one wheel has no traction at all, others use more complex gearing and can transfer torque from one to another at some multiple (called a Torsen Differential) and cannot drive when one wheel is completely unloaded.
- jonmrodriguez 12y agoAwesome, thank you!
- clebio 12y agoThe actual explanation doesn't start until about 2 minutes in: https://www.youtube.com/watch?v=K4JhruinbWc#t=110 https://www.youtube.com/watch?v=K4JhruinbWc#t=110
- Yahivin 12y agoI like how they start ghost riding the whip at 8:45 https://www.youtube.com/watch?v=K4JhruinbWc#t=519 https://www.youtube.com/watch?v=K4JhruinbWc#t=519
- amenghra 12y agoI remember building lego cars which had a differential: http://groups.csail.mit.edu/drl/courses/cs54-2001s/images/legodiff.jpg http://groups.csail.mit.edu/drl/courses/cs54-2001s/images/le...
- charlieok 12y agoI remember reading through David Macaulay's “The Way Things Work” as a kid, soaking up the illustrations until I understood each one. It was life-changing. However, I remember having trouble with one page in particular -- the one describing differential gears. Of course, video would probably have helped a lot :)
- blt 12y agoThis is the best technical education video I've ever seen. If all information were available in such an easy to understand form, the world would be full of geniuses. The level of effort is astounding. The "support" part holding the spokes looks cast. They couldn't have possibly cast that part specifically for this video... could they?
- niels_olson 12y agocasting one-offs with a disposable form (wax, styrofoam) isn't particularly difficult or expensive. They use big basins full of super-fine sand: a great insulator and the grains are too tightly packed for the liquid metal to flow into the tiny spaces between them. We used to do it in high school shop class.
- mickcartwright 12y agolove the clarity, simplicity and enunciation
- nikant 12y agoGreat Video:)
- sisar 12y agoAny idea for what purpose was this video originally made?