Talk:Pulley

message: This page seems to get an unusually high incidence of vandalism.  Normally, a page has to be either a featured article or a very public and controversial topic to be vandalized this regularly.  Any hypotheses about why this page is so regularly attacked?  Rossami (talk) 20:21, 28 February 2006 (UTC)
replies: text: Pretty sure "Pulley" is British slang for Handjob. I've heard it a few places across the web. I'm assuming that's it's consistently  vandalized. Restocking (talk) 18:59, 12 November 2012 (UTC)
thread_title: Vandalism question

message: I added a theory of operation section, and used two of the pulley system images from the original article. I have removed the simplest compound pulley image, because its practical implementation is not different from the diagram, which is the case for the other two - they are different from the diagrams. I also removed the "historical images of pulleys" because it didn't seem to add much, without an explanation. Maybe it could go back in under a history section? PAR 04:51, 5 March 2006 (UTC)
replies: text: Nope, nothing.  The forces on either side of the pulley are the same regardless of the radius of the wheel.  Okay, actually that's for a theoretical pulley.  A real pulley will suffer some slight amount of friction between the fibers of the rope as it goes around the pulley.  A larger diameter pulley will deform the rope less resulting in slightly less friction.  But that is a miniscule effect compared to the normal forces used on the pulley.  Rossami (talk) 00:24, 8 September 2007 (UTC)
thread_title: Theory of operation

message: I think information should be added to this article to recognize a "sheave" as a type of pulley.  I'm probably not the right person to add this, but I do know that they are commonly used in oceanic applications suspended from an A-frame on a ship and also for oil drilling.  65.165.72.203 17:17, 18 October 2006 (UTC)
thread_title:  Additional Information Needed 

message: Bad picture.  The pulleys shown are what are called belt pulleys.  A rubberized loop of belt  wraps around both pulleys.  One pulley is the source of power, the other receives power through the belt.  This was a common way to transfer rotational power prior to about 1940. Threshing machines received power through the belt and belt pulleys from the steam engines. 
A picture of the type of pulleys described in the article is needed.  Also the article should also mention belt pulleys as well. --69.5.156.155 06:22, 24 Sep 2004 (UTC)
thread_title:  Regarding Pictures 

message: Rossami: I am not quite sure how to use this system, but the Leavenworth Arrangement has not been known since Archimedes. It took me a year to discover, and I am an intelligent fellow. You will not find this knowledge in books, because this is the first time it has been published. If you are of the opinion that knowledge is never lost and rediscovered, or that such a thing could not be discovered in this day and age, I challenge you to find fault with the math, with the arrangement, and a previously published source describing the arrangement. Besides those objections, there can be no reasonable objection to the additions.--MarkLeavenworth 03:01, 19 October 2007 (UTC)
replies: text: @Mark: wikipedia has a very strict policy about original research: it is not accepted. See this page Wikipedia:No original research. VanBurenen 07:52, 19 October 2007 (UTC)

text: You have been asked several times now to go read the Wikipedia policy against original research.  It does not matter how obvious or self-evident you think this is.  Encyclopedias are, by definition, tertiary sources.  We synopsize the writings of others.  Until it is verifiably published in a reliable source, it has no place in the encyclopedia.  Either cite your sources or stop adding this content.  Rossami (talk) 21:47, 19 October 2007 (UTC)

text: Uhm, maybe this is just too obvious, but isn't this entire entry made up original research? There isn't a single source sited on it. If the Leavenworth arrangement works, then it is just a valid as all the other unsited information on this page. Siting sources is important but there isn't there some allowance for the duh factor? Should the number 10 entry and all its occurrences be removed from wikipedia because there are no references sited? Does someone need a reference to say the sky is Azure on a clear bright day? Come to think of it, there are no references to indicate user:VanBurenen even exits, or user:MarkLeavenworth, or myself for that matter. We need to all be deleted from wikipedia promptly.  —Preceding unsigned comment added by 76.191.180.179 (talk) 10:30, 29 February 2008 (UTC)
thread_title:  Re:Leavenworth Arrangement 

message: i see nothing on these fascinating pulleys. would anyone be willing to write anything?
Chris(talk) 18:03, 23 October 2008 (UTC)
replies: text: See differential pulley.  (I'm not familiar enough to know if the Weston design is significantly different from the generic "differential pulley" design.)  Note:  That article could probably use expansion if you have time and interest.  And this article should probably include a "see also" link.  Rossami (talk) 18:19, 23 October 2008 (UTC)
thread_title: Weston Differential Pulleys

message: Do timing belts, and other ribbed belts run on sprockets, notched pulleys, or something else by another name? What distinguishes a pully from a sprocket? The teeth, the flanges, or what runs on them, a belt or a chain? Does anyone have a definitive reference, or is this just a murky area?
: This is essentially the same question as was asked about bicycle chains above, I think.  So in the context of the six simple machines, yes, a timing belt arrangement would be considered a pully with a mechanical advantage of 1.  The Oxford English Dictionary (the only citation currently on the page) sets a different definition - one based on a perceived need to differentiate between specific kinds of things that act as a pulley.  OED requires a pulley to have flanges.  The simple-machine definition is based more on the transformation of forces.  Rossami (talk) 21:25, 4 June 2010 (UTC)
replies: text:  Similar, but that was asking about wheels over which a chain runs. This is asking about wheels over which a belt runs. I believe the context of simple machines is no help in this case, because pulley and sprocket appear to be the same simple machine. OED does not require pulleys to have flanges. See definition "c. A wheel or drum fixed on a shaft and turned by a belt, cable, etc., for the application or transmission of power, or to guide the belt." -AndrewDressel (talk) 21:38, 4 June 2010 (UTC)
replies: text:  I misspoke about OED requiring flanges.  Thank you for the correction.  Nevertheless, my point is that a pulley and a sprocket are the same simple machine.  Modern usage carries the connotation of ribs or chains for "sprockets" (fairly strictly) and relatively smooth ropes or belts for "pulleys" (more loosely) but they share exactly the same mechanical concept and can both be referred to as pulleys in the larger sense.  Rossami (talk) 21:52, 4 June 2010 (UTC)
thread_title:  Timing belts 

message: A very large section was recently added to this article focused on the "Methods of mounting" a pulley wheel to a shaft.  I have removed the section pending discussion here because
# It is not unique to pulleys.  Any structure fixed to a shaft would use the same techniques.
# The level of detail is disproportionate to the rest of the article
# The writing style encroaches on the WP:NOTHOWTO prohibitions
If anyone can recover useful content from the section, it can be found in the collapsed content immediately below.  Rossami (talk) 21:44, 4 June 2010 (UTC)
replies: text: I agree with point 1, disagree with point 2, and strongly disagree with point 3. As such, I think the above text should just be moved to drive shaft. Wizard191 (talk) 18:10, 6 June 2010 (UTC)
thread_title:  Mounting 

message: Pulleys are commonly mounted to shafts in the following ways:
* Interference fit 
** Variations: 
*** Interference fit alone 
*** Interference fit and key (key may fasten by press fit, taper, or both) 
*** Interference fit, key, and set screw above the key 
** Assembly: 
*** Application of heat expands the pulley, temporarily removing the interference long enough to ease the assembly. The heat can be supplied from heat guns or blow torches; the former are gentler to the paint and metal tempering. 
*** Pressing via shop press, arbor press, or hammer can also be used. Caution is required, because excessive axial pressing or hammering can damage the bearings of the shaft. Heating the pulley helps to avoid this by reducing the amount of axial force needed. 
** Disassembly: Bearing pullers are tools that grip the pulley (or bearing or gear) with jaws while a screwing action pulls it off the shaft. 
* Methods using screw threads 
** Advantages: These methods are advantageous (compared to press fit) because in the field, no heat or pressing are needed to do the assembly or disassembly. 
** Variations: 
*** Set screw alone (suitable for low-torque applications) 
*** Split taper bushings 
**** Principles: 
***** These work on the same basic principle as collets. The pulley's bore and the bushing's OD are both tapered. Threaded fasteners hold the pulley to the bushing, wedging the tapers to the point that they hold fast, and squeezing the bore of the bushing against the shaft, causing that interface also to hold fast. 
***** Typically keys are also used as further insurance against relative rotation. 
**** Variations: 
***** Custom (bespoke) bushings 
***** Quick-disconnect (QD) bushings, a standardized subset of split taper bushings, available off the shelf from industrial supply houses 
*** Bolted joints 
**** The face of the pulley may be bolted to a flange on the shaft. The flange may be an integral part of the shaft or be a separate part that is pressed, welded or otherwise fastened to the shaft. 
*** Threaded shaft 
**** The shaft end may be threaded, allowing a large nut to fasten the pulley directly against a shoulder behind it
|}
:I agree with point 1, disagree with point 2, and strongly disagree with point 3. As such, I think the above text should just be moved to drive shaft. Wizard191 (talk) 18:10, 6 June 2010 (UTC)
thread_title:  Methods of mounting

message: There was a subtle mistake in two of the figures. In diagrams 3 and 3a, horizontal bars are used to add two forces. In the original version of the figures, the weight was suspended below the midpoint of the bar. This would cause the bar not to be in equilibrium; it would twist clockwise. To make the system function as intended, it's necessary to slide the weight over to a position 1/3 of the way over from the left. I'm in the process of correcting the two diagrams.Fashionslide (talk) 18:58, 18 September 2011 (UTC)
thread_title: mistakes in two figures

message: This article is linked to the article simple machine as one of the six simple machines identified by Renaissance scientists.  It is therefore one of the articles used by elementary school teachers when they introduce technology and mechanical advantage.  I would like to make some revisions to this article that include this historical perspective while maintaining the spirit of modern machine theory.  I will work to avoid disrupting other content in this article. Prof McCarthy (talk) 16:46, 11 December 2011 (UTC)
replies: text: Support. Excellent suggestion; excellent plan. — ¾-10 16:55, 11 December 2011 (UTC)
thread_title:  Pulley as a simple machine 

message: A new section has been added to this article describing a method for the calculation of the mechanical advantage of a block and tackle system by using a count of the upward direction and downward directed rope.  As far as I can tell this assumes that an assembly of pulleys into a block and tackle lifts a load vertically by pulling downwards on a rope.  It is not clear how this is calculated if the pulley system is used to pull a load horizontally along the ground, particularly if the pulley system is configured to pulling the the same direction as the movement of the load. Prof McCarthy (talk) 23:37, 30 October 2012 (UTC)
thread_title:  Upward and downward direction of pulley rope 

message: Is a step pulley one of these types?  If so can we have a section on it?
IceDragon64 (talk) 22:27, 9 November 2014 (UTC)
replies: text: Yes—that's funny, I thought we had a mention already in this article, but I just hit ctrl-f for "step" and found nothing.  A step pulley is to V belts exactly what a cone pulley is to flat belts. (In fact, it is nothing more than idiomatic accident that the names are not interchangeable—the concept is identical). I will add a mention. — ¾-10 00:37, 10 November 2014 (UTC)
thread_title:  Step Pulley? 

message: There's nothing really on the history of this machine. I would've thought that would be significant given the fact that the pulley is one of 6 simple machines. Rayman60 (talk) 19:08, 27 November 2015 (UTC)
thread_title:  History 

message: Substituted at 03:33, 30 April 2016 (UTC)
thread_title: Assessment comment

message: All hoisting systems described use at least two independent pulleys, invariably housed in blocks. Obviously, something needs to support a pulley's axle, which can be a simple U-shaped piece, as in the accompanying picture. Does that qualify as a "block"?  And what about one-pulley systems? The picture shows one very common configuration of a rope and pulley system involving precisely one pulley, yet the article states that "rope and pulley system" means the same as "block and tackle", which the latter article defines as "a system of two or more pulleys". Also, the description here refers to "the set of pulleys that form the moving block", implying that there is always a pulley that moves with the load – which need not be the case, as shown in the picture.  --Lambiam 08:46, 6 June 2018 (UTC)
thread_title:  One-pulley hoisting systems 

message: http://www.ckit.co.za/secure/conveyor/troughed/pulleys/pulley_lagging.htm:
>>>Lagging is the term used to describe the application of a coating, cover or wearing surface which is sometimes applied to pulley shells.
>>>Lagging is often applied in order to extend the life of the shell by providing a replaceable wearing surface or to improve the friction between the belt and the pulley. Notably drive pulleys are often rubber lagged for exactly this reason.  — Preceding unsigned comment added by 46.166.187.95 (talk) 00:47, 27 June 2018 (UTC)
thread_title:  Add info on "pulley lagging"? 

message: I'm proposing that this article Sheave should be merged into Pulley, as the sheave is part of a pulley. Furthermore, the article hasn't had any change and lacks any inline citations. In my opinion, the merger would likely not cause any opposition, and wouldn't cause any harm to anyone's current plans to edit it.  Explodicator7331 (talk) 15:58, 18 February 2022 (UTC)
replies: text: Klbrain (talk) 10:05, 27 December 2022 (UTC)
thread_title:  Proposed merge of [[Sheave]] into [[Pulley]] 

message: What a 3 body of pulley 136.158.124.59 (talk) 12:23, 18 April 2022 (UTC)
thread_title:  Science 

message: What is  pulley 102.85.146.153 (talk) 20:45, 14 June 2023 (UTC)
thread_title:  Science