Talk:Crank (mechanism)

Popular Culture
File:Square Steam Logo.png Has anyone considered adding a mention to the Steam logo (which is a crank) to this page? — Preceding unsigned comment added by 151.225.64.22 (talk) 01:44, 3 February 2014 (UTC)

Drawing a Crank
Okay, so a crank is a... what? How on EARTH can I draw that on a SIMPLE diagram? no no crank best crank

Train window
I've never seen a train window operated by a crank. What country does this refer to? Biscuittin (talk) 21:16, 28 December 2007 (UTC)

Earliest evidence for crank and connecting rod
I removed the inclusion of the alleged ancient Egyptian crank and connecting rod mechanism because it rests on erroneous interpretation of the cited reference and a lack of true understanding of the mechanism. In the context in which the crank and connecting rod mechanism appears, Robert Moores (p.146) does not speak of the ancient Egyptian saw, but of its "modern configuration as a slab-making machine". The entire absence of a crank and connecting rod mechanism in the ancient machine is corrobated by fig. 11 which shows the "operation of the 4th Dynasty drag saw". Gun Powder Ma (talk) 01:49, 4 October 2009 (UTC)

Great history section
Just wanted to congratulate Gun Powder Ma and Jagged 85 on an excellent expansion of the history section. It looks comprehensive, well written, and thoroughly sourced (how often do you find that in a WP article?). Another thing I like is that it's tightly and concisely written, without the bloat found in many articles. Kudos! -- Chetvorno TALK 02:48, 22 March 2010 (UTC)


 * Requests_for_comment/Jagged_85/Evidence shows that Jagged 85 had his own issue with this article.--Stone (talk) 15:30, 25 October 2010 (UTC)

Saw Mill Illustration
The perspective seems to off quite a bit. The water wheel appears to be an oval and the peg gear seems to have pegs going in different direction than the other pegs. I found it to be a quite confusing illustration. Cipherseed (talk) 22:42, 10 March 2011 (UTC)


 * Yes, the drawing isn't perfect, but it still illustrates the crank correctly. Wizard191 (talk) 17:50, 16 March 2011 (UTC)

patented by James Pickard
Sun and planet gear says the crank was patented by James Pickard (perhaps just its use with a flywheel) but it's not mentioned in this article. - Rod57 (talk) 00:45, 11 September 2012 (UTC)
 * As far as I know, James Pickard patented a particular application of the crank for use on steam engines, not the crank itself. A mention here would be appropriate as long as it doesn't imply that he invented the crank.--Roly (talk) 15:54, 21 February 2013 (UTC)

Crank Cart
It is now: "Around 1480, the early medieval rotary grindstone was improved with a treadle and crank mechanism. Cranks mounted on push-carts first appear in a German engraving of 1589." But the reference says:


 * "A. Schroeder, Die Entwicklung des Schleiftechniks (Haya-Weser, 1931), 31, fig. 8, holds that the first authentic rotary grindstone fitted with treadle and crank appears c. 1480 in a copper engraving by Israhel von Meckemen, while (60, fig. 58) the earliest mounted on a push-cart is found in a Cologne engraving of 1589." White (1962), p. 167

I read it the way that not the push-cart had a crank but it only transported the rotary grindstone. The first known hand driven crank cart was build c. 1655 by the 22 year old legless(?) clockmaker Stephan Farfler in Altdorf. Reported with image by J. G. Doppelmayr in Nuernberg 1730. -- Portolanero (talk) 19:10, 15 November 2012 (UTC)

Crank/windlass
Under Midle Ages, the text says "Medieval cranes were occasionally powered by cranks, although more often by windlasses". Surely the crank forms part of the windlass, doesn't it, or have I got my terminology wrong?--Roly (talk) 14:14, 11 April 2013 (UTC)

Compound Crank
Why does this article mention something, yet not explain what the hell it is? — Preceding unsigned comment added by 71.221.252.148 (talk) 14:39, 25 May 2013 (UTC)

Error in photograph description.
Current article begins :- "A crank is an arm attached at right angles to a rotating shaft" The text accompanying the 1939 Tibet photograph states :- "The perpendicular handle of such rotary handmills works as a crank" No it does not, the handle is parallel to the axis of rotation, not perpendicular.

The handle functions the same as the web in a crankshaft, it provides eccentricity. The crank in the photograph is the arm of the person. AnnaComnemna (talk) 18:48, 16 October 2015 (UTC)

Scope of "crank"? Is linear motion an essential part?
Re this image deletion

Does a "crank", as defines the scope of this article, require there to be both a crank and also a connecting rod or yoke to convert to or from purely linear motion?

The two mechanisms are distinct and the development of one from the other is an interesting historical innovation that warrants coverage. But for an article at Crank, I think we have to take the inclusive view and cover both. The mechanism of crank alone is widespread for hand-operating machinery, with countless examples and at least two illustrations here. The linguistic description (English at least) includes both mechanisms under the same term. Andy Dingley (talk) 09:07, 3 May 2017 (UTC)

Medieval Near East
The article states, in sub section Medieval Near East:

"The crank appears in the mid-9th century in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices.[39] These devices, however, made only partial rotations and could not transmit much power,[40] although only a small modification would have been required to convert it to a crankshaft.[41]"

However, Lynn Townsend White Jr. in his Medieval Technology and Social Change (1962) argues (p. 111): "At the beginning of the 1400's, at least twelve centuries after it was known in China and six centuries after its first appearance in [Western] Europe, the crank was still a dormant element in technology. As for Islam and Byzantium, I find no firm evidence of even the simplest application of the crank until al-Jazari's book of A.D. 1206. " --Gerard1453 (talk) 18:14, 19 December 2017 (UTC)

Crank and Connecting Rod in China
There is an issue with the following sentence:


 * "However, the potential of the crank of converting circular motion into reciprocal one never seems to have been fully realized in China, and the crank was typically absent from such machines until the turn of the 20th century."

The use of a crank and connecting rod (for converting reciprocal motion to circular motion or vice versa) is certainly not 'typically absent from such machines until the turn of the 20th century'. In fact the first instance of a crank and connecting rod was dated to the Han dynasty, used to operate a quern. I had given the source, which says what I'm saying, so I'm not sure why it's being deleted in favor of a claim that's saying such contraptions didn't exist when we have evidence that they did exist in multiple forms prior to the 20th century and the evidence is pretty overwhelming.

Source title: International Symposium on History of Machines and Mechanisms, page 249

Publisher: Springer Science and Business Media

From the book, it says:
 * "From the above discussion, the crank and connecting-rod mechanism featured with eccentric lug was adopted for a long period of time in ancient Chinese blasting apparatus, textile machinery and agricultural machinery, and its appearance was no later than the Western Han Dynasty. It was first applied in manually operated quern and long, and the gradually evolved into different crank connecting-rod devices, used in the inter-conversion of rotary and reciprocating (rectilinear) motion in specific situations".

'--ArchimedesTheInventor (talk) 10:15, 4 April, 2020 (UTC)


 * White is aware of such examples as he himself cites the Han era bellow and the farmyard machine in his discussion (p. 104). Still, he arrives at the conclusion you want to remove, because the Chinese knew only these and very few more uses. Note that a single German technical book of the 16th century gives as much as 45 different machines that use cranks. So it is fair to say, as White does, that the potential of cranks wasn't fully realized in China. Gun Powder Ma (talk) 00:18, 3 April 2020 (UTC)


 * What you are saying pertains to White being aware that the Chinese used the generic crank, White is not saying that the Chinese lacked usage of the crank, but a very specific type of crank called the "Crank and Connecting Rod". White is unfortunately not much aware of all the uses that the Chinese had for the "Crank and Connecting Rod". His mention of the crank for Han era bellows and farmyard machinery is in regards to the generic crank, NOT the "crank and connecting rod". White came to the conclusion that the pre-20th century Chinese lacked the crank and connecting rod, his only example is his statement that "'a single crank with connecting-rod is found there [China] applied to a man-powered rice-hulling mill by 1462, if we may judge from the similar illustrations of a Japanese edition of 1676 and a Chinese edition of 1696, both independently derived from an edition of that date'" (pg 114), when in fact such hulling mills operated by the crank and connecting rod were in existence prior to 0 AD. So this means White was clearly unaware of them.
 * White's page 104 that you mentioned only says the following:
 * '"The earliest crank motion occurs in the previously mentioned water-powered bellows in A.D. 31 in China and the first crank is in a Han-dynasty model (Fig. 4) from north-western Honan, now in the William Rockhill Nelson Gallery in Kansas City, which dates from not later than the end of the second Christian century. It shows a farmyard machine for winnowing husked rice with a cranked rotary fan."'
 * Hence, he said not a single word about the crank and connecting rod, and his example about the cranked rotary fan would not have included a crank and connecting rod, the machine only utilizes a crank. It's surprising he mentions Han bellows utilizing the crank, when later Chinese bellows would utilize a "crank and connecting rod". He claims the Chinese "'had not reached that stage where continuous rotary motion is substituted for reciprocating motion'", even though the Chinese bellow did in fact use a crank and connecting rod for precisely that effect by at least the Song dynasty of around 1000 AD, but White only says that the Han dynasty bellow used a crank (with no mention of the crank and connecting rod for later Chinese bellows).
 * Now even if you want to keep White's quote, why delete all the usages for the Chinese crank and connecting rod? Those have been proven as provided by the source I gave, the other states listed in this article such as Rome gave even fewer examples of the crank and connecting rod (ie only one example in which they used it for sawmills). So I don't see how it's justified to edit out the obviously more-than-one different Chinese usages for the crank and connecting rod which includes multiple examples, and replacing it with White's quote which gives the incorrect impression that the Chinese didn't even have it until the 20th century, as not even White would agree with that. At the very least, let me add in all the usages that the Chinese had for the crank and connecting rod, as the article right now gives the incorrect impression that the Chinese didn't even have them until the 20th century, when in reality they found multiple uses for them. --ArchimedesTheInventor (talk) 20:17, 2 April, 2020 (UTC)
 * The following is a summary of the list of examples given for the usage of "crank-and-connecting-rod" (not just some generic crank) in Chinese history, from the book "International Symposium on the History of Machines and Mechanisms
 * Facsimile of long, Western Han era stone relief
 * Figurine of Man with long, Eastern Han
 * Long unearthed in a tomb of the Eastern Wu Dynasty
 * Longs in Treatise on Agriculture, Yuan Dynasty
 * Longs in Complete Treatise on Agriculture
 * Candle-making long, Exploitation of the Works of Nature, Ming Dynasty
 * Wooden-type long, Exploitation of the Works of Nature, Ming Dynasty
 * Soil-type(rattan) long, Exploitation of the Works of Nature, Ming Dynasty
 * water powered flour-sifter ,Zhakou Panche Tujuan, Song dynasty
 * water powered flour-sifter, in the Treatise on Agriculture, Yuan Dynasty
 * treadle spinning wheel, in Biographies of Famous Ladies, Eastern Jin Dynasty
 * treadle spinning wheel, in New Compiled Biographies of Ancient Famous Ladies
 * Three types of treadle spinning wheels recorded by Treatise on Agriculture, Yuan Dynasty
 * North-type treadle silk-reeling machine, Treatise on Agriculture (uses pedal attached to the connecting rod)
 * South-type pedeal silk-reeling machine, Treatise on Agriculture (uses a treadle which is the connecting rod)
 * treadle silk-reeling machine, Fundamental of Agriculture and Sericulture, early Yuan Dynasty
 * treadle silk-reeling machine, Can Sang He Bian, Qing dynasty
 * pedal silk-reeling machine, Cang Sang He Bian, Qing dynasty
 * water powered bellows, Treatise on Agriculture, Yuan dynasty
 * All the above examples either changes reciprocating motion into circular motion, or vice versa as that's what a crank-and-connecting rod does. Having read some of these sources myself, this author wasn't even giving a comprehensive list because Chinese usages for the crank-and-connecting-rod for things such as the single-man operated dragon's backbone as drawn in the Exploitation of the Works of Nature are missing. White, however, only mentions a single usage for the Chinese crank-and-connecting-rod dated to 1462 but no other examples. From this single example he concludes that: '"The crank in its simple rudimentary form we find in the [modern] Chinese windlass, which use of the device, however, has apparently not given the impulse to change reciprocating into circular motion in other contrivances"'. Compare that single example he mustered to those 21 examples listed above (and it's not even a comprehensive list), and it becomes clear White didn't have all the information at his disposal. In page 172 White stated that usage of the crank-and-connecting rod was "common" in the days of Leonardo and gave "8 examples already listed" (I actually count only three for the page he pointed to) as well as 4 other ones dating to periods prior to Leonardo's death, making a total of a dozen examples to prove that the crank-and-connecting rod was common. The number of Chinese examples given exceeds this. As far as the history of the Chinese crank-and-connecting rod is concerned, Lynn White's book is outdated and should be treated as such. --ArchimedesTheInventor (talk) 13:59, 2 April, 2020 (UTC)
 * I am counting three different applications only: bellows, spinning wheel and flour sifter. White already cited two of these three uses on p. 104 when he came to his conclusion that the potential of crank motion was not properly realized. So I don't see why he should not be considered still up to date. You are citing altogether only 20 instances of the use of the crank in machines for just as many centuries which is really not a lot. Gun Powder Ma (talk) 23:33, 6 April 2020 (UTC)
 * As I said before, White did not cite the usage of the crank-and-connecting rod for "two of these three uses" (it's actually five uses, so I don't know how you counted but the number isn't correct). I gave you the relevant quote directly from White regarding that, anyone can see White was citing the Chinese usage of the crank, NOT the "crank-and-connecting-rod" which is a more complicated invention than the crank. If White cited more than one example for the Chinese usage of the crank-and-connecting rod, NOT the crank, you should quote him regarding that. White only cited 1 instance for 1 application of the Chinese usage of the crank-and-connecting rod, I've also already shown you the quote for that too. Even in this one instance, he cited a 1462 AD example of a crank and connecting rod being used for a mill, and it seems this is the earliest Chinese example he knew of. However, in just the "International Symposium on the History of Machines" there's about 21 instances spread through 5 (not 3 ) different applications: Querns, bellows, treadle spinning wheel, flour sifter, and silk-reeling machines (and it's not even comprehensive), all of which point to Chinese usage of the crank-and-connecting-rod, with examples going back to the ancient period.
 * Why can't these five different Chinese applications for the crank-and-connecting rod be listed in the article simply for being "two few different applications" when:
 * the Roman examples in this article only shows 1 application for the crank-and-connecting rod: sawmill.
 * the Renaissance examples in this article only shows 1 application for the crank-and-connecting rod: water pump
 * the Middle Eastern examples in this article only shows 1 application for the crank-and-connecting rod: water lifting machines
 * Having five different applications is more than having 1 application. If five isn't enough diversity of applications to be put into the article, then none of these singular applications for Rome/Renaissance Europe/Middle East would be enough, and they should all be deleted if that is the standard you're using. As I said, if you want to re-introduce the quote from Lynn White about the Chinese lacking examples for converting rotary motion to reciprocal motion or vice versa(as that's what a crank-and-connecting rod does), fine, but it also needs to be said that Lynn White was only aware of one singular example for one singular application of the Chinese using the "crank and connecting rod" dating to 1462 when in fact the "international Symposium on the History of Machines" listed more than 20 examples spread over multiple usages of the crank-and-connecting rod dating back around 1500 years before that singular example. I already said you can leave the quote from White within the article, but the article also needs to show the evidence outside of White's book. Things that White didn't know of also needs to be presented. Lastly, the quote from White which I deleted was about how White believed the Chinese "'had not reached that stage where continuous rotary motion is substituted for reciprocating motion'". This is not about Chinese usage of a generic crank but the crank-and-connecting rod. The crank in and of itself do not convert rotary motion to reciprocating motion, so White's describing a crank-and-connecitng rod. ArchimedesTheInventor (talk) 20:09, 6 April, 2020 (UTC)


 * And to re-emphasize that White did not say anything about a 'crank-and-connecting rod' being used for Chinese bellows, and hence didn't know about such an example even though they do exist, here is an author re-affirming exactly that:
 * Clerks and Craftsmen in China and the West, Joseph Needham, pg 195
 * '"Lynn White, p. 81, misinterprets the construction of the hydraulic blowing-machine of the Nung Shu in exactly the same sense. The water-wheel, he says, 'turned a vertical shaft carrying an upper wheel which, by means of an eccentric peg and a cord, worked the bellows of a furnace for smelting iron'. But no such system was used; text and drawing fully concur in making the connecting-rod a rigid bar."'
 * Now if you have a quote from Lynn White which can disprove this, a quote which shows he knew the Chinese used the "crank and connecting rod" to operate their bellows, I think this is the time to share it. As of far, from the quote I already shared, Lynn White only went as far as saying the Chinese used a crank to operate their bellows, but he did not say "crank and connecting rod" even though the Chinese did use it. As of far, I've shown Lynn White only knew the Chinese used the crank-and-connecting rod in 1 singular instance for 1 singular application dating to 1462, when in fact there are many instances of them using the crank-and-connecting rod spread through at least 5 different applications listed in "The International Symposium on the History of Machines" with the first instance dating to before 0 AD, and the book's not being comprehensive about all the instances/applications either. ArchimedesTheInventor (talk) 20:38, 6 April, 2020 (UTC)

Technology
I want to know about advantages of cranks Thandi Mgxaji (talk) 16:47, 2 March 2023 (UTC)

Technology
grade 8 advantages of cranks mechanism Thandi Mgxaji (talk) 16:54, 2 March 2023 (UTC)