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| Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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What are these fittings called?
On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote:
.... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? .... About 8" (two feet / pi). Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? |
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#2
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 07:33:46 -0700 (PDT), rangerssuck
wrote: On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Uh, that's two feet *times* pi. g -- Ed Huntress Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? |
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#3
Posted to rec.crafts.metalworking
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What are these fittings called?
On 08/13/2014 9:33 AM, rangerssuck wrote:
On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). .... C2=pi*D2; C1=pi*D1 -- C2-C1=pi*(D2-D1) = 2*pi ft -- |
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#4
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wednesday, August 13, 2014 10:44:45 AM UTC-4, Ed Huntress wrote:
On Wed, 13 Aug 2014 07:33:46 -0700 (PDT), rangerssuck wrote: On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Uh, that's two feet *times* pi. g yeah, well, haven't finished the morning coffee yet. Besides, by the time they finished building all those little standoffs, I'd have been paid and spent the money. So sue me ;-) And it's all a trick question anyway: EVERYONE knows the earth is flat. -- Ed Huntress Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? |
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#5
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 07:54:08 -0700 (PDT), rangerssuck
wrote: On Wednesday, August 13, 2014 10:44:45 AM UTC-4, Ed Huntress wrote: On Wed, 13 Aug 2014 07:33:46 -0700 (PDT), rangerssuck wrote: On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Uh, that's two feet *times* pi. g yeah, well, haven't finished the morning coffee yet. Besides, by the time they finished building all those little standoffs, I'd have been paid and spent the money. So sue me ;-) And it's all a trick question anyway: EVERYONE knows the earth is flat. Don't forget that the string will stretch. And there is the catenary curve droop of the string *between* the standoffs. Those two factors work against each other. Are we having fun yet? d8-) -- Ed Huntress Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? |
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#6
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 07:33:46 -0700, rangerssuck wrote:
On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Let the height be h, and let x = 1 mile, and the length increase d = 1 inch. Apply the Pythagorean theorem to a right triangle with hypoteneuse x/2 + d/2, base x/2, and height h: h^2 + (x/2)^2 = (x/2 + d/2)^2, or 4*h^2 + x^2 = (x+d)^2 = x^2 + 2dx + d^2 from which 4*h^2 ~ 2dx so h^2 ~ dx/2, h ~ sqrt(dx/2) ~ 178 inches ~ 14' 10" -- jiw |
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#7
Posted to rec.crafts.metalworking
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What are these fittings called?
rangerssuck wrote in
: On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. |
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#8
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 16:38:19 +0000 (UTC), Doug Miller
wrote: rangerssuck wrote in : On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. Looking at it simplistically, it's around 17 feet (somebody did the math; I checked it, and it was right). However, in practice, what would it be? Probably less than a foot, because of the compressive elastic modulus of the rails, lifted up, and, once again, the catenary sag of the rails, which would consume almost all of the linear expansion in the curve. That's my story and I'm sticking with it. d8-) -- Ed Huntress |
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#9
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wednesday, August 13, 2014 12:38:19 PM UTC-4, Doug Miller wrote:
rangerssuck wrote in : On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. Makes a pretty good case for expansion joints. |
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#10
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wednesday, August 13, 2014 12:48:24 PM UTC-4, Ed Huntress wrote:
On Wed, 13 Aug 2014 16:38:19 +0000 (UTC), Doug Miller wrote: rangerssuck wrote in : On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. Looking at it simplistically, it's around 17 feet (somebody did the math; I checked it, and it was right). However, in practice, what would it be? Probably less than a foot, because of the compressive elastic modulus of the rails, lifted up, and, once again, the catenary sag of the rails, which would consume almost all of the linear expansion in the curve. That's my story and I'm sticking with it. d8-) -- Ed Huntress Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. |
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#11
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 09:55:52 -0700 (PDT), rangerssuck
wrote: On Wednesday, August 13, 2014 12:48:24 PM UTC-4, Ed Huntress wrote: On Wed, 13 Aug 2014 16:38:19 +0000 (UTC), Doug Miller wrote: rangerssuck wrote in : On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. Looking at it simplistically, it's around 17 feet (somebody did the math; I checked it, and it was right). However, in practice, what would it be? Probably less than a foot, because of the compressive elastic modulus of the rails, lifted up, and, once again, the catenary sag of the rails, which would consume almost all of the linear expansion in the curve. That's my story and I'm sticking with it. d8-) -- Ed Huntress Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. g True. But there have been alleged occassions of welded rail buckling from heat. I never checked this out, but I remember the question coming up when they converted much of the Northeast Corridor line to welded rail and concrete ties. 'Dunno. There are too many other things to check out. -- Ed Huntress |
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#12
Posted to rec.crafts.metalworking
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What are these fittings called?
On 08/13/2014 11:55 AM, rangerssuck wrote:
.... Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. The new continuous rail rely simply on sufficient hold-down force to restrain it -- I was wondering not terribly long ago as was watching Union Pacific replacing a bunch of the main line thru here as were having not uncommon KS summer days of 105F or on occasion quite a bit higher than that...so I looked up and as far as I could find that's the way it's done. No magic low-expansion alloys, or other tricks I could find... -- |
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#13
Posted to rec.crafts.metalworking
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What are these fittings called?
dpb wrote:
On 08/13/2014 11:55 AM, rangerssuck wrote: ... Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. The new continuous rail rely simply on sufficient hold-down force to restrain it -- I was wondering not terribly long ago as was watching Union Pacific replacing a bunch of the main line thru here as were having not uncommon KS summer days of 105F or on occasion quite a bit higher than that...so I looked up and as far as I could find that's the way it's done. No magic low-expansion alloys, or other tricks I could find... I was told that the new long rails that are used these days are installed under tension with some sort of winch like device to counteract expansion in hot weather. |
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#14
Posted to rec.crafts.metalworking
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What are these fittings called?
On 08/13/2014 4:46 PM, Cydrome Leader wrote:
wrote: On 08/13/2014 11:55 AM, rangerssuck wrote: ... Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. The new continuous rail rely simply on sufficient hold-down force to restrain it -- I was wondering not terribly long ago as was watching Union Pacific replacing a bunch of the main line thru here as were having not uncommon KS summer days of 105F or on occasion quite a bit higher than that...so I looked up and as far as I could find that's the way it's done. No magic low-expansion alloys, or other tricks I could find... I was told that the new long rails that are used these days are installed under tension with some sort of winch like device to counteract expansion in hot weather. Don't recalling finding that in the looking I did, but it certainly wasn't exhaustive. I don't see anything looking like it would serve that purpose on the UP work train here at the moment; will have to look more closely. Would be nice if they'd let me close enough to talk but doubt will before they get antsy... -- |
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#15
Posted to rec.crafts.metalworking
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What are these fittings called?
On 8/13/2014 11:55 AM, rangerssuck wrote:
On Wednesday, August 13, 2014 12:48:24 PM UTC-4, Ed Huntress wrote: On Wed, 13 Aug 2014 16:38:19 +0000 (UTC), Doug Miller wrote: rangerssuck wrote in : On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Nope. Correct answer is 2 pi feet. Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Nearly fifteen feet. Looking at it simplistically, it's around 17 feet (somebody did the math; I checked it, and it was right). However, in practice, what would it be? Probably less than a foot, because of the compressive elastic modulus of the rails, lifted up, and, once again, the catenary sag of the rails, which would consume almost all of the linear expansion in the curve. That's my story and I'm sticking with it. d8-) -- Ed Huntress Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. Tracks are welded end to end to limit the wear and tear on the wheels. They have expansion spots that are switch joints and the long expansion runs down the spur. I talk to two different RR line members most every day. Martin |
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#16
Posted to rec.crafts.metalworking
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What are these fittings called?
dpb wrote:
On 08/13/2014 4:46 PM, Cydrome Leader wrote: wrote: On 08/13/2014 11:55 AM, rangerssuck wrote: ... Ed, in practice there'd be expansion joints or someone looking for a job. It would also probably make a hell of a noise. The new continuous rail rely simply on sufficient hold-down force to restrain it -- I was wondering not terribly long ago as was watching Union Pacific replacing a bunch of the main line thru here as were having not uncommon KS summer days of 105F or on occasion quite a bit higher than that...so I looked up and as far as I could find that's the way it's done. No magic low-expansion alloys, or other tricks I could find... I was told that the new long rails that are used these days are installed under tension with some sort of winch like device to counteract expansion in hot weather. Don't recalling finding that in the looking I did, but it certainly wasn't exhaustive. I don't see anything looking like it would serve that purpose on the UP work train here at the moment; will have to look more closely. Would be nice if they'd let me close enough to talk but doubt will before they get antsy... I came across this stuff while looking up rail pulling. http://www.pinterest.com/pin/425801339739519202/ http://www.minibooster.com/fileadmin.../rail-pull.jpg the hydraulic device looks like it makes the most sense. it's not like one could pull on a rail and stretch it out all that far anyways. |
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#17
Posted to rec.crafts.metalworking
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What are these fittings called?
On 08/14/2014 4:19 PM, Cydrome Leader wrote:
.... I came across this stuff while looking up rail pulling. http://www.pinterest.com/pin/425801339739519202/ EPA'll simply _love_ that one...  http://www.minibooster.com/fileadmin.../rail-pull.jpg the hydraulic device looks like it makes the most sense. it's not like one could pull on a rail and stretch it out all that far anyways. 'Pends on how hard you pull... -- |
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#18
Posted to rec.crafts.metalworking
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What are these fittings called?
On Wed, 13 Aug 2014 15:34:47 +0000 (UTC), James Waldby
wrote: On Wed, 13 Aug 2014 07:33:46 -0700, rangerssuck wrote: On Wednesday, August 13, 2014 6:43:55 AM UTC-4, Doug Miller wrote: ... Related thought experiment: suppose you have a string wrapped tightly around the surface of the earth. How much longer does that string need to be, if you want to put it on one-foot-high standoffs all around the planet? ... About 8" (two feet / pi). Related thought experiment: Suppose you have a mile of railroad track. Suppose it gets really hot and the track expands (in length) by one inch. Suppose that, due to the expansion, the track buckles in the middle, forming an isosceles triangle. How high will the bump in the middle be? Let the height be h, and let x = 1 mile, and the length increase d = 1 inch. Apply the Pythagorean theorem to a right triangle with hypoteneuse x/2 + d/2, base x/2, and height h: h^2 + (x/2)^2 = (x/2 + d/2)^2, or 4*h^2 + x^2 = (x+d)^2 = x^2 + 2dx + d^2 from which 4*h^2 ~ 2dx so h^2 ~ dx/2, h ~ sqrt(dx/2) ~ 178 inches ~ 14' 10" Its gonna be miles longer Gunner -- "Living in the United States now is like being a Tampon. We're in a great place, just at a bad time." |
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