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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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Interesting slip rolls
Skip down to 3:00
http://www.youtube.com/watch?v=m_-iPpEuWRA I don't know if, technically, they are _slip_ rolls, since I don't see how any of the rolls would open. Still interesting, though, & much simpler than most. Especially using the cranks & link in place of gears or sprockets & chain. The action is somewhat different than the usual slip rolls in that the material is not pinched between drive rolls. Is there a specific name for this type of roll? Bob |
#2
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Interesting slip rolls
Bob Engelhardt fired this volley in
: Especially using the cranks & link in place of gears or sprockets & chain. Especially interesting is that it wouldn't work at all without some "work" pinched snugly between the rolls. Think what would happen if there were no workpiece. The non-driven roll would simply stall when the crank link hit dead-aft-center, and could not be reasonably expected to advance or retract, no matter which way the driven roll was turned. It _is_ interesting, because the workpiece is part of the mechanism. LLoyd |
#3
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Interesting slip rolls
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70: The non-driven roll would simply stall when the crank link hit dead-aft-center, and could not be reasonably expected to advance or retract, no matter which way the driven roll was turned. BTW... You might argue that there could be another crank link at the other end 90-degrees out of phase with the one we could see. That certainly would solve the "aft-dead-center" problem. OK... That would work if you turned the front roller with a gear from the crank, but how would that work with a hand crank arm on one end of either roller? And if there were a gear turning either, then why use a link? G Interesting mechanism, indeed! I think it's one of the few I've seen where the work is part of the machine. LLoyd |
#4
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Interesting slip rolls
On Dec 12, 6:29*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: "Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley 8.3.70: The non-driven roll would simply stall when the crank link hit dead-aft-center, and could not be reasonably expected to advance or retract, no matter which way the driven roll was turned. BTW... You might argue that there could be another crank link at the other end 90-degrees out of phase with the one we could see. *That certainly would solve the "aft-dead-center" problem. OK... That would work if you turned the front roller with a gear from the crank, but how would that work with a hand crank arm on one end of either roller? And if there were a gear turning either, then why use a link? G Interesting mechanism, indeed! *I think it's one of the few I've seen where the work is part of the machine. LLoyd Lloyd, look carefully! There is a link at both ends of the machine. One appears to be 90 degrees out of phase with the camera link. Just like the old steam locomotives! Ingenious! Paul |
#5
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Interesting slip rolls
On Dec 12, 3:52*pm, Bob Engelhardt wrote:
Skip down to 3:00http://www.youtube.com/watch?v=m_-iPpEuWRA I don't know if, technically, they are _slip_ rolls, since I don't see how any of the rolls would open. *Still interesting, though, & much simpler than most. *Especially using the cranks & link in place of gears or sprockets & chain. The action is somewhat different than the usual slip rolls in that the material is not pinched between drive rolls. Is there a specific name for this type of roll? Bob Would annealing the rim have helped? Karl |
#6
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Interesting slip rolls
KD7HB fired this volley in news:f31366a2-f42a-430a-
: Lloyd, look carefully! There is a link at both ends of the machine. One appears to be 90 degrees out of phase with the camera link. Just like the old steam locomotives! Ingenious! Ah... I see it now. I wondered how the other link could clear the crank arm, but I see that the handle turns the link, not the roller. Oh, well, my _idea_ was unique, anyway G. LLoyd |
#7
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Interesting slip rolls
On Dec 13, 8:38*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: Lloyd, look carefully! There is a link at both ends of the machine. One appears to be 90 degrees out of phase with the camera link. Just like the old steam locomotives! Ingenious! Ah... I see it now. *I wondered how the other link could clear the crank arm, but I see that the handle turns the link, not the roller. LLoyd I can not see well enough to tell, but I think the handle turns the roller. Dan |
#8
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Interesting slip rolls
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#9
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Interesting slip rolls
On Dec 13, 9:33*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul |
#10
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Interesting slip rolls
On Dec 13, 1:31*pm, KD7HB wrote:
On Dec 13, 9:33*am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang |
#11
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Interesting slip rolls
On Dec 12, 7:52*pm, Bob Engelhardt wrote:
Skip down to 3:00http://www.youtube.com/watch?v=m_-iPpEuWRA I don't know if, technically, they are _slip_ rolls, since I don't see how any of the rolls would open. *Still interesting, though, & much simpler than most. *Especially using the cranks & link in place of gears or sprockets & chain. The action is somewhat different than the usual slip rolls in that the material is not pinched between drive rolls. Is there a specific name for this type of roll? Bob The roll arrangement that he has is similar to the one on my HF 3 in 1 shear/brake/roll except that the bending roll on mine can be quick- released. I thought that the "slip" in slip rolls meant that the bending roll was not gear-driven (like the feed rollers) and therefore allowed to slip with the workpiece. However I see that your use of the word is more proper. There's a reference to slip rolls in an old book on sheet-metal work by Joseph Rose: http://books.google.com/books?id=YDY...page&q&f=false Maybe the one in the video can be just called a "roll forming machine" (i.e. without the "slip" as a modifier.) |
#12
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Interesting slip rolls
wolfgang wrote:
This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. .... This type of bending roll arrangement is not suitable for sheet metal work. .... Thank you, thank you, thank you. You just saved me a pile of work. I was all set to build one of these for sheet metal. Boy, I would have been ****ed when I found that it didn't work! RCM: there is still a signal in all the noise, Bob |
#13
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Interesting slip rolls
Denis G. wrote:
... I thought that the "slip" in slip rolls meant that the bending roll was not gear-driven (like the feed rollers) and therefore allowed to slip with the workpiece. However I see that your use of the word is more proper. ... Don't put too much credence in my use - I probably just made it up G. |
#14
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Interesting slip rolls
On Dec 15, 12:58*pm, Bob Engelhardt wrote:
Denis G. wrote: *... * I thought that the "slip" in slip rolls meant that the bending roll was not gear-driven (like the feed rollers) and therefore allowed to slip with the workpiece. *However I see that your use of the word is more proper. *... Don't put too much credence in my use - I probably just made it up G. Bob E: Glad to be of service.;-)) BTW the "slip" part comes from the fact that the outside bearing of the top roll can EASILY be disengaged to allow a closed cylinder to be slipped from the roll former. For really large pressure vessels (oil refineries, etc.) where the perimeter requires several lengths of steel plate the "slip" part is not really necessary. But in power plant boiler work larger headers are rolled from a single plate per section. For this work the "slip" part is an economic necessity. Very good friend of mine was pressure vessel engineer at one of my employers and we used to kid him about his play with "tin cans". These cans had wall thicknesses varying from 3" to 6"! Serious fabrication work in anyone's book. Wolfgang |
#15
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Interesting slip rolls
On Dec 14, 5:15*pm, wolfgang wrote:
On Dec 13, 1:31*pm, KD7HB wrote: On Dec 13, 9:33*am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. |
#16
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Interesting slip rolls
Denis G. wrote:
On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. The link pin creates the offset, and carries the torque from the hand crank to the crank arm. 'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD. |
#17
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Interesting slip rolls
On Dec 16, 3:45*am, David Billington
wrote: Denis G. wrote: On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. *I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD.- Hide quoted text - - Show quoted text - Oops, you're right! What I was imagining would likely be impossible anyways, unless it was a forged piece. |
#18
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Interesting slip rolls
On Dec 16, 8:56*am, "Denis G." wrote:
On Dec 16, 3:45*am, David Billington wrote: Denis G. wrote: On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled.. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. *I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD.- Hide quoted text - - Show quoted text - Oops, you're right! *What I was imagining would likely be impossible anyways, unless it was a forged piece. 6ft was the drum's nominal dia; I don't recall whether ID or OD. It wasn't my project. I got involved when my friend complained about the number of plates that had been broken trying to roll the steam drum cylindrical cans. It was customer-supplied material and we had the material specs for welding purposes. I advised my friend to subject the plates to a stress relief at 50 deg F. below the quenching temp. of the plates. This was done and all went well. These were Wilhelmsburger bending rolls from Germany and cost $CDN4.5 million in the late '70's. The 3 rolls were about 36 to 42 inches in dia. The upper roll was fixed in position with its outboard bearing movable for "slip" purposes. The lower 2 rolls were driven from a large gear box via massive universal joints since the bottom rolls moved up and down under hydraulic pressure. This machine was mounted in a pit so that the bottom of the top roll was a foot or so above floor level. The financial argument for its acquisition is quite a tale in itself. My boss made the argument before I joined the corp. In essence the contract couldn't absorb the entire cost so management was going to decline the contract! We bought the rolls based on this argument, executed the contract and many others, and made $$$ doing it. If you are interested I can repeat this tale here. Wolfgang |
#19
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Interesting slip rolls
On Wed, 15 Dec 2010 12:40:09 -0500, Bob Engelhardt
wrote: wolfgang wrote: This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. ... This type of bending roll arrangement is not suitable for sheet metal work. ... Thank you, thank you, thank you. You just saved me a pile of work. I was all set to build one of these for sheet metal. Boy, I would have been ****ed when I found that it didn't work! RCM: there is still a signal in all the noise, Bob I have used pyramid rolls to bend 28 gauge sheet. It just depends whether they were designed to cope with thin work or not. Mark Rand RTFM |
#20
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Interesting slip rolls
On Dec 16, 5:40*pm, Mark Rand wrote:
On Wed, 15 Dec 2010 12:40:09 -0500, Bob Engelhardt wrote: wolfgang wrote: This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. * ... This type of bending roll arrangement is not suitable for sheet metal work. * ... Thank you, thank you, thank you. *You just saved me a pile of work. *I was all set to build one of these for sheet metal. *Boy, I would have been ****ed when I found that it didn't work! RCM: there is still a signal in all the noise, Bob I have used pyramid rolls to bend 28 gauge sheet. It just depends whether they were designed to cope with thin work or not. Mark Rand RTFM Mark, here is the question: Did these rolls look like the one as posted by the OP? Or were your rolls able to pinch the thin sheet so as to propel it through the rolls? Wolfgang |
#21
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Interesting slip rolls
On Dec 16, 3:14*pm, wolfgang wrote:
On Dec 16, 8:56*am, "Denis G." wrote: On Dec 16, 3:45*am, David Billington wrote: Denis G. wrote: On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up.. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. *I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD.- Hide quoted text - - Show quoted text - Oops, you're right! *What I was imagining would likely be impossible anyways, unless it was a forged piece. 6ft was the drum's nominal dia; *I don't recall whether ID or OD. *It wasn't my project. *I got involved when my friend complained about the number of plates that had been broken trying to roll the steam drum cylindrical cans. *It was customer-supplied material and we had the material specs for welding purposes. *I advised my friend to subject the plates to a stress relief at 50 deg F. below the quenching temp. of the plates. *This was done and all went well. These were Wilhelmsburger bending rolls from Germany and cost $CDN4.5 million in the late '70's. *The 3 rolls were about 36 to 42 inches in dia. *The upper roll was fixed in position with its outboard bearing movable for "slip" purposes. The lower 2 rolls were driven from a large gear box via massive universal joints since the bottom rolls moved up and down under hydraulic pressure. *This machine was mounted in a pit so that the bottom of the top roll was a foot or so above floor level. The financial argument for its acquisition is quite a tale in itself. My boss made the argument before I joined the corp. *In essence the contract couldn't absorb the entire cost so management was going to decline the contract! *We bought the rolls based on this argument, executed the contract and many others, and made $$$ doing it. If you are interested I can repeat this tale here. Wolfgang- Hide quoted text - - Show quoted text - Yes, I'm curious to hear the story. It sounds like the company took a bit of a risk with the investment. I can only guess that there was no one willing or able to do this job. |
#22
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Interesting slip rolls
On Dec 16, 8:29*pm, "Denis G." wrote:
On Dec 16, 3:14*pm, wolfgang wrote: On Dec 16, 8:56*am, "Denis G." wrote: On Dec 16, 3:45*am, David Billington wrote: Denis G. wrote: On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter.. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. *I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD.- Hide quoted text - - Show quoted text - Oops, you're right! *What I was imagining would likely be impossible anyways, unless it was a forged piece. 6ft was the drum's nominal dia; *I don't recall whether ID or OD. *It wasn't my project. *I got involved when my friend complained about the number of plates that had been broken trying to roll the steam drum cylindrical cans. *It was customer-supplied material and we had the material specs for welding purposes. *I advised my friend to subject the plates to a stress relief at 50 deg F. below the quenching temp. of the plates. *This was done and all went well. These were Wilhelmsburger bending rolls from Germany and cost $CDN4.5 million in the late '70's. *The 3 rolls were about 36 to 42 inches in dia. *The upper roll was fixed in position with its outboard bearing movable for "slip" purposes. The lower 2 rolls were driven from a large gear box via massive universal joints since the bottom rolls moved up and down under hydraulic pressure. *This machine was mounted in a pit so that the bottom of the top roll was a foot or so above floor level. The financial argument for its acquisition is quite a tale in itself. My boss made the argument before I joined the corp. *In essence the contract couldn't absorb the entire cost so management was going to decline the contract! *We bought the rolls based on this argument, executed the contract and many others, and made $$$ doing it. If you are interested I can repeat this tale here. Wolfgang- Hide quoted text - - Show quoted text - Yes, I'm curious to hear the story. *It sounds like the company took a bit of a risk with the investment. *I can only guess that there was no one willing or able to do this job. There were only a few companies in Canada that were able to execute this job. This was 35 years ago but here is the story from memory. The contract was to design, construct, and erect the heavy water plant separating towers for the heavy water plant in the Canadian province of Quebec, near the town of Gentilly, on the south side of the St. Lawrence River. About 100 miles east of Montreal. The 3 big towers were on the order of 30ft dia x 300ft tall with a wall thickness of roughly 3.5in. There were two somewhat smaller towers, for a total of 5. The price for the bending rolls was $4.5 million Canadian dollars and without this machine these plates could not be formed in-house. Subletting the forming was out of the question for quality, contract, and corporate political reasons. The competitive price quoted for this contract could only absorb $2 million Canadian dollars for this capital equipment, any higher and the price would have been non-competitive. The corporate brass was not willing to stick its neck out for the additional $2.5 million, and was on the verge of turning down this job. My boss-to-be was at this final decision-making meeting; he was a really sharp cookie and I learned one hell of a lot from him and he from me. We were to make a dynamite project team that could handle anything and make a buck. Anyway, my boss-to-be asked at this meeting: "Anyone here know what a set of USED bending rolls of this size would cost right now?" A few phone calls later got the answer: $2.5 million Canadian dollars. None were available but that was the going price for the most recent sales. Well, said boss-to-be, let the contract absorb $2 million dollars, and when the job is done we'll pull the machine out and sell it on the used machinery market for $2.5 million. The stunned management agreed with this impeccable logic! And guess what? 3 years or so later when the forming work was completed NOBODY dared talk about selling these rolls because we got so much work for them subsequently. I'd joined the corp early through this contract and did some large piping nozzle stress analysis work on it. When I discussed this with my boss he allowed that he knew full-and- well at the time of this decision that this subsequent additional work could very well happen but upper management would not entertain that risk. But these guys were not dummies either and they probably suspected too what would happen. But my boss' proposal allowed them to make that decision based on corporate policy and not sticking their collective necks out. Anyway as a young engineer I was duly impressed by this tale. Perhaps some of you reading this can make use of it? Wolfgang |
#23
Posted to rec.crafts.metalworking
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Interesting slip rolls
On Dec 17, 1:21*am, wolfgang wrote:
On Dec 16, 8:29*pm, "Denis G." wrote: On Dec 16, 3:14*pm, wolfgang wrote: On Dec 16, 8:56*am, "Denis G." wrote: On Dec 16, 3:45*am, David Billington wrote: Denis G. wrote: On Dec 14, 5:15 pm, wolfgang wrote: On Dec 13, 1:31 pm, KD7HB wrote: On Dec 13, 9:33 am, "Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote: " fired this volley in news:cc5a1ba4- : I can not see well enough to tell, but I think the handle turns the roller. The hand crank turns an offset crank arm on the roller. *The link pin creates the offset, and carries the torque from the hand crank to the crank arm. *'Tis a weak point of possible failure, methinks; but it allows the mechanism to work, which it could not if the link were attached directly to one side or the other of the hand crank.. *If the pin is stout enough, it would be strong enough -- it just doesn't look very big. LLoyd The top roller looks a lot like one of the commercial rollers I have in my junk pile(shop!). The two powered rollers are of similar size, but must be made by the operator. The rest appear to be welded up. I wonder if I have enough junk to make one? Might be an interesting way of recycling metal. Anyone else see the old steam tractor in the background? Watch the roller sequence and look at the back wall. Paul This bending roll arrangement as shown above is called 3-roll pyramid, and is typically used to roll heavy plate for large pipe, pressure vessels, and steam drums. *Bar stock, as shown, can also be rolled. For round rod a groove is helpful. For it to function it is necessary that the work piece be stout enough so as to carry a substantial force so as to drive the work piece through the rolls via friction. A former employer of mine had a German made machine that would roll 6" thick plate into a 6' dia. cylinder cold. *It would also break that plate if it was too hard! This type of bending roll arrangement is not suitable for sheet metal work. *For sheet metal the top roll and one bottom roll must be able to securely pinch the sheet metal in order to drive it past the bending roll, which is offset and is adjustable so as to determine the work diameter to be rolled. To recapitulate: *For thick material only the top roll requires adjustment for driving force and work diameter. For sheet metal work the top roll is adjustable to pinch the sheet metal against one of the bottom rolls, and the second bottom roll is adjustable separately to determine the final work piece diameter. There is a 4 roll pyramid arrangement to do thinnish plate work; *top and middle bottom roll to pinch the sheet, outside bottom rolls adjustable to bend the sheet and determine work diameter. Wolfgang- Hide quoted text - - Show quoted text - I'm not sure how the roll arrangement would be to bend a 6" thick plate into a 6" ID cylinder cold. *I imagine that it must have taken many passes through the rolling machine and maybe with multiple bending rolls probably all hydraulically driven. If you read the post again it said 6" thick plate into 6' diameter, that's 6 foot diameter and it didn't specify whether that was ID or OD.- Hide quoted text - - Show quoted text - Oops, you're right! *What I was imagining would likely be impossible anyways, unless it was a forged piece. 6ft was the drum's nominal dia; *I don't recall whether ID or OD. *It wasn't my project. *I got involved when my friend complained about the number of plates that had been broken trying to roll the steam drum cylindrical cans. *It was customer-supplied material and we had the material specs for welding purposes. *I advised my friend to subject the plates to a stress relief at 50 deg F. below the quenching temp. of the plates. *This was done and all went well. These were Wilhelmsburger bending rolls from Germany and cost $CDN4.5 million in the late '70's. *The 3 rolls were about 36 to 42 inches in dia. *The upper roll was fixed in position with its outboard bearing movable for "slip" purposes. The lower 2 rolls were driven from a large gear box via massive universal joints since the bottom rolls moved up and down under hydraulic pressure. *This machine was mounted in a pit so that the bottom of the top roll was a foot or so above floor level. The financial argument for its acquisition is quite a tale in itself. My boss made the argument before I joined the corp. *In essence the contract couldn't absorb the entire cost so management was going to decline the contract! *We bought the rolls based on this argument, executed the contract and many others, and made $$$ doing it. If you are interested I can repeat this tale here. Wolfgang- Hide quoted text - - Show quoted text - Yes, I'm curious to hear the story. *It sounds like the company took a bit of a risk with the investment. *I can only guess that there was no one willing or able to do this job. There were only a few companies in Canada that were able to execute this job. This was 35 years ago but here is the story from memory. The contract was to design, construct, and erect the heavy water plant separating towers for the heavy water plant in the Canadian province of Quebec, near the town of Gentilly, on the south side of the St. Lawrence River. *About 100 miles east of Montreal. The 3 big towers were on the order of 30ft dia x 300ft tall with a wall thickness of roughly 3.5in. There were two somewhat smaller towers, for a total of 5. The price for the bending rolls was $4.5 million Canadian dollars and without this machine these plates could not be formed in-house. Subletting the forming was out of the question for quality, contract, and corporate political reasons. The competitive price quoted for this contract could only absorb $2 million Canadian dollars for this capital equipment, any higher and the price would have been non-competitive. The corporate brass was not willing to stick its neck out for the additional $2.5 million, and was on the verge of turning down this job. My boss-to-be was at this final decision-making meeting; he was a really sharp cookie and I learned one hell of a lot from him and he from me. *We were to make a dynamite project team that could handle anything and make a buck. Anyway, my boss-to-be asked at this meeting: "Anyone here know what a set of USED bending rolls of this size would cost right now?" *A few phone calls later got the answer: $2.5 million Canadian dollars. *None were available but that was the going price for the most recent sales. Well, said boss-to-be, *let the contract absorb $2 million dollars, and when the job is done we'll pull the machine out and sell it on the used machinery market for $2.5 million. The stunned management agreed with this impeccable logic! And guess what? 3 years or so later when the forming work was completed NOBODY dared talk about selling these rolls because we got so much work for them subsequently. *I'd joined the corp early through this contract and did some large piping nozzle stress analysis work on it. When I discussed this with my boss he allowed that he knew full-and- well at the time of this decision that this subsequent additional work could very well happen but upper management would not entertain that risk. *But these guys were not dummies either and they probably suspected too what would happen. *But my boss' proposal allowed them to make that decision based on corporate policy and not sticking their collective necks out. Anyway as a young engineer I was duly impressed by this tale. Perhaps some of you reading this can make use of it? Wolfgang- Hide quoted text - - Show quoted text - Interesting story! Shortly after college I worked for a constuction management firm in Boston working on a nuclear project in Shippingport, PA. I was in the pipe stress group and mostly reviewed construction drawings and did nomographs to see whether any changes required more extenisive FEA. That was the early 80s and I think that the analysis was being done on IBM 370s. I was finishing my BSME nights and got swepted up in company layoffs shortly thereafter. Unfortunately, this country is still skittish about nuclear power and I'm afraid that this has had political consequences that we are still feeling today. |
#24
Posted to rec.crafts.metalworking
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Interesting slip rolls
On Thu, 16 Dec 2010 16:08:06 -0800 (PST), wolfgang
wrote: I have used pyramid rolls to bend 28 gauge sheet. It just depends whether they were designed to cope with thin work or not. Mark Rand RTFM Mark, here is the question: Did these rolls look like the one as posted by the OP? Or were your rolls able to pinch the thin sheet so as to propel it through the rolls? Wolfgang They were pyramid rolls, with the lower two rolls driven and the upper, central, slip roll free. Needs a nice, free-running slip roll. Ball or roller bearings are a must. Mark Rand RTFM |
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