Talk:Watt's linkage

Merge proposal
I propose that the main portion of Parallel motion should be merged into Watt's linkage. The Parallel motion is entirely about Watt's linkage which essentially duplicates what is in the acticle Watt's linkage. However, there is more than one way of achieving parallel motion and it would be appropriate for the Parallel motion article to discuss the matter in general, citing Watt's linkage as a particular example. Gaius Cornelius (talk) 12:02, 6 August 2008 (UTC)
 * Parallel motion is a more generic term, Watt's linkage is specific example. The parallel motion article does have duplicated material, but there is material that could be added to that article that does not belong here.--RDBury (talk) 15:25, 19 March 2010 (UTC)

I think the two articles should be merged--the overlap is very great.DonSiano (talk) 22:53, 3 June 2010 (UTC)

There's a lot of overlap, but the concepts are still distinct and do, IMHO, support separate articles. There are two distinctions: We should always bear the reader community in mind, not just a strict taxonomy. The goal here isn't to "store knowledge", it's to "offer encyclopedia articles" (the two aren't quite the same). Even though there's an argument that a Watt's Linkage is a Watt's Linkage wherever, the readers coming to this article are probably coming from the direction of either steam engines or car suspension, rarely both. Separate, focussed articles with linkage gives those readers a better answer. Andy Dingley (talk) 09:04, 4 June 2010 (UTC)
 * Linkages, vs. Watt's specific invention. If there are other parallel linkages of note, the linkage article can expand.
 * Uses made of them. Beam engines vs. rear axles.


 * Oppose, I think Andrew's explanation is good. Greglocock (talk) 01:02, 5 June 2010 (UTC)

Broken animation
Animated GIF images in Wikipedia currently only work if they are inserted into an article at 100% scale. The Watt's linkage animation was rescaled from 454 pixels to 350 pixels, to make it "look nice", and it turned into a static image, even though the caption said it was animated. If there's a compelling reason to have it 350 pixels wide in the article, the original creator needs to regenerate the image from the source material as a 350 pixel GIF animation. Perhaps sometime in the future the Wiki software will be fixed to rescale every layer in a multilayer GIF image and preserve the animation timing information.&mdash;QuicksilverT @ 20:58, 26 January 2011 (UTC)

Watt's 'Grasshopper' parallel motion
James Watt installed a completely different parallel motion on the engines that he supplied for the Crossness Pumping Station's engines, which is known as the 'grasshopper' parallel motion. There is no reference to it here (and perhaps there should be). 109.156.49.202 (talk) 18:54, 22 November 2011 (UTC)

Is this correct?
In the lead paragraph, the following doesn't make sense to me and doesn't look right: "Its applications include doubling the power of a piston engine by allowing two pistons to connect to a single beam" This is certainly not the prime purpose of the linkage and I can't see how it would work this way. If it is correct, then an example would be appropriate. Roly (talk) 11:47, 22 January 2013 (UTC)
 * It's poorly worded, but it's important. The goal was less about "two pistons" and more about "one double-acting piston". Before this date and this mechanism, beam engines had been single-acting, using chains over arch heads. Andy Dingley (talk) 12:24, 22 January 2013 (UTC)
 * That's what I thought. Double acting makes more sense. If that's what was intended then I'll reword it. Roly (talk) 12:41, 22 January 2013 (UTC)

Parallel motion revisited
The parallel motion article explains the pantograph addition to Watt's parallel linkage. It seems that the addition gives a more convenient overall design which looks to have been of practical importance at the time. However both articles give an interesting reference which quotes Watt writing to his son in 1808 "I am more proud of the parallel motion than of any other invention I have ever made." Watt's description of what he is calling "parallel motion" is describing what WP is calling the "parallel linkage". Reading further Watt had previously written to Boulton in 1784 "about 5 feet in the height of the [engine] house may be saved ... I think it ... one of the most ingenious simple pieces of mechanism I have contrived". To me (WP:OR} this seems to be describing the linkage incorporating the pantograph addition.

Now, I suppose Watt's terminology at the time may not be critical now (even Franz Reuleaux says "even a thinker like Watt was at fault in the essential elucidation of the matter") but I am interested in how current reliable sources name these two linkages. At the moment the two articles, while they may both be technically correct, are confusing in their naming and fail to explain the historical relationship between the two inventions. Thincat (talk) 10:39, 12 May 2013 (UTC)
 * I think I have sorted this our so I'll do some editing. Thincat (talk) 18:56, 12 May 2013 (UTC)

Ackermann steering geometry
Currently there is no mention of (link to) Ackermann steering geometry in Watt's linkage. Peter Horn User talk 02:46, 13 July 2021 (UTC)

And what reliable source says there should be? Greglocock (talk) 05:14, 13 July 2021 (UTC)