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#1
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Odd cassette hub problem
Interesting and unusual failure.
The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
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#2
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Odd cassette hub problem
On 9/26/2019 9:58 PM, AMuzi wrote:
Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged.Â* The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) -- - Frank Krygowski |
#3
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Odd cassette hub problem
On 9/26/2019 9:11 PM, Frank Krygowski wrote:
On 9/26/2019 9:58 PM, AMuzi wrote: Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots in dark rooms, lights on for visitors. SARA were early versions of multiple-format robots (Shimano Automatic Robot Assembler or something like that) made by Panasonic to Shimano's design. That was several geological ages ago in robot time. I'm sure whatever they use now are more like FABNUC assembly robots. https://www.youtube.com/watch?v=h-3xz8RLJI8 https://www.youtube.com/watch?v=xoJ_L-KgdhY https://www.youtube.com/watch?v=Djla...79350D4AC4589A etc -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#4
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Odd cassette hub problem
On Thursday, September 26, 2019 at 10:43:34 PM UTC-4, AMuzi wrote:
On 9/26/2019 9:11 PM, Frank Krygowski wrote: On 9/26/2019 9:58 PM, AMuzi wrote: Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots in dark rooms, lights on for visitors. SARA were early versions of multiple-format robots (Shimano Automatic Robot Assembler or something like that) made by Panasonic to Shimano's design. I wonder if you were shown SCARA robots. That's a particular robot geometry optimized for top-down assembly operations. (The acronym stands for Selective Compliance Assembly Robotic Arm.) https://www.youtube.com/watch?v=vKD20BTkXhk The distinguishing characteristic is: the main pivoting axes of the robot arm are vertical. (There are usually two of those.) So the first two joints of the arms swing sort of like a door swings. There is another sliding axis that goes up and down, reminiscent of a vertical hydraulic cylinder. Assembly operations are set up so that vertical motion inserts the part, whatever it may be. The final trick is, the pivoting axes can unlock during vertical part insertion. It helps parts settle into position. SCARA robots are really good at assembly if the insertion of parts is a vertical motion. So if the hub was held open end up, a SCARA robot would be a good choice. (That's one type of robot I worked with.) Again, just wondering. - Frank Krygowski |
#5
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Odd cassette hub problem
On 9/26/2019 11:22 PM, Frank Krygowski wrote:
On Thursday, September 26, 2019 at 10:43:34 PM UTC-4, AMuzi wrote: On 9/26/2019 9:11 PM, Frank Krygowski wrote: On 9/26/2019 9:58 PM, AMuzi wrote: Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots in dark rooms, lights on for visitors. SARA were early versions of multiple-format robots (Shimano Automatic Robot Assembler or something like that) made by Panasonic to Shimano's design. I wonder if you were shown SCARA robots. That's a particular robot geometry optimized for top-down assembly operations. (The acronym stands for Selective Compliance Assembly Robotic Arm.) https://www.youtube.com/watch?v=vKD20BTkXhk The distinguishing characteristic is: the main pivoting axes of the robot arm are vertical. (There are usually two of those.) So the first two joints of the arms swing sort of like a door swings. There is another sliding axis that goes up and down, reminiscent of a vertical hydraulic cylinder. Assembly operations are set up so that vertical motion inserts the part, whatever it may be. The final trick is, the pivoting axes can unlock during vertical part insertion. It helps parts settle into position. SCARA robots are really good at assembly if the insertion of parts is a vertical motion. So if the hub was held open end up, a SCARA robot would be a good choice. (That's one type of robot I worked with.) Again, just wondering. - Frank Krygowski That's impressive but not what I saw then. The SARA units were uniform design, made of square channel and painted bright blue with SARA in white, each with different end tooling (punch, drill, press, grasp, etc) and very crude compared to modern units. Still amazing at that time. p.s. When I first saw those assembling cassette hubs, the hub shells were two pieces pressed together and the body was stamped to the right side. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#6
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Odd cassette hub problem
On Friday, 27 September 2019 08:36:49 UTC-4, AMuzi wrote:
On 9/26/2019 11:22 PM, Frank Krygowski wrote: On Thursday, September 26, 2019 at 10:43:34 PM UTC-4, AMuzi wrote: On 9/26/2019 9:11 PM, Frank Krygowski wrote: On 9/26/2019 9:58 PM, AMuzi wrote: Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots in dark rooms, lights on for visitors. SARA were early versions of multiple-format robots (Shimano Automatic Robot Assembler or something like that) made by Panasonic to Shimano's design. I wonder if you were shown SCARA robots. That's a particular robot geometry optimized for top-down assembly operations. (The acronym stands for Selective Compliance Assembly Robotic Arm.) https://www.youtube.com/watch?v=vKD20BTkXhk The distinguishing characteristic is: the main pivoting axes of the robot arm are vertical. (There are usually two of those.) So the first two joints of the arms swing sort of like a door swings. There is another sliding axis that goes up and down, reminiscent of a vertical hydraulic cylinder. Assembly operations are set up so that vertical motion inserts the part, whatever it may be. The final trick is, the pivoting axes can unlock during vertical part insertion. It helps parts settle into position. SCARA robots are really good at assembly if the insertion of parts is a vertical motion. So if the hub was held open end up, a SCARA robot would be a good choice. (That's one type of robot I worked with.) Again, just wondering. - Frank Krygowski That's impressive but not what I saw then. The SARA units were uniform design, made of square channel and painted bright blue with SARA in white, each with different end tooling (punch, drill, press, grasp, etc) and very crude compared to modern units. Still amazing at that time. p.s. When I first saw those assembling cassette hubs, the hub shells were two pieces pressed together and the body was stamped to the right side. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 Were the units you saw being assembled in 1982 the SHimano AX line of hubs and cassettes? Cheers |
#7
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Odd cassette hub problem
On 9/27/2019 8:43 AM, Sir Ridesalot wrote:
On Friday, 27 September 2019 08:36:49 UTC-4, AMuzi wrote: On 9/26/2019 11:22 PM, Frank Krygowski wrote: On Thursday, September 26, 2019 at 10:43:34 PM UTC-4, AMuzi wrote: On 9/26/2019 9:11 PM, Frank Krygowski wrote: On 9/26/2019 9:58 PM, AMuzi wrote: Interesting and unusual failure. The cassette had a dramatic 6!8mm runout, the sort of thing one usually associates with a steel freewheel hub collapse where the right hub half has crept inward. But this was a Shimano brand cassette hub, a product of notable dependability and longevity. Date code is October, 2005. http://www.yellowjersey.org/photosfr...st/cshub19.jpg The robot dropped the nice steel cassette body onto the hubshell but in this one-in-a-million incidence, the cassette body landed above the hub splines, not fully engaged. The robot dropped the cassette body bolt in and torqued it properly but the body was not where it should have been. Axle was not bent, bearing adjustment was normal, wheel centered correctly and true, and so on. Except the cassette sprockets wavered on the hub. I removed the raised material on the hub splines and remounted the cassette body with no further issues. Interesting. My guess is that the robot (if indeed it was a robot) went through its motions perfectly, to within a few thousandths of an inch. They very rarely fail in that task. But the mechanism that fed the part to the robot may have glitched and presented a part that was somehow out of position. Parts feeding can be tricky, and lots of robot assembly lines won't correct for a mis-fed part. They go through the motions as if the part were correctly oriented. If you're "lucky," so to speak, there may be a (hopefully minor) crash, and a safety sensor will stop operation, indicating something is wrong. Looks like in this case, the error wasn't enough to trigger any sensors. (If it was not a robot but a human worker, well, perhaps they had too much fun the night before.) As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots in dark rooms, lights on for visitors. SARA were early versions of multiple-format robots (Shimano Automatic Robot Assembler or something like that) made by Panasonic to Shimano's design. I wonder if you were shown SCARA robots. That's a particular robot geometry optimized for top-down assembly operations. (The acronym stands for Selective Compliance Assembly Robotic Arm.) https://www.youtube.com/watch?v=vKD20BTkXhk The distinguishing characteristic is: the main pivoting axes of the robot arm are vertical. (There are usually two of those.) So the first two joints of the arms swing sort of like a door swings. There is another sliding axis that goes up and down, reminiscent of a vertical hydraulic cylinder. Assembly operations are set up so that vertical motion inserts the part, whatever it may be. The final trick is, the pivoting axes can unlock during vertical part insertion. It helps parts settle into position. SCARA robots are really good at assembly if the insertion of parts is a vertical motion. So if the hub was held open end up, a SCARA robot would be a good choice. (That's one type of robot I worked with.) Again, just wondering. - Frank Krygowski That's impressive but not what I saw then. The SARA units were uniform design, made of square channel and painted bright blue with SARA in white, each with different end tooling (punch, drill, press, grasp, etc) and very crude compared to modern units. Still amazing at that time. p.s. When I first saw those assembling cassette hubs, the hub shells were two pieces pressed together and the body was stamped to the right side. Were the units you saw being assembled in 1982 the SHimano AX line of hubs and cassettes? Cheers Probably yes that year although they were making less expensive units the day I visited. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#8
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Odd cassette hub problem
On Thursday, September 26, 2019 at 9:43:34 PM UTC-5, AMuzi wrote:
As early as 1982 (the first time I visited a Shimano plant in Shin Osaka) cassette hub assembly was done by SARA robots -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 I was all ready to jump down your throat for lying to us about there being freehubs and cassettes in 1982. But I did a Google search and found Sheldon Brown has the 1982 Shimano catalog on his website and there are pictures of Shimano freehubs and cassettes. I sure thought cassettes did not come out until mid 1980s. Only freewheels before then. |
#9
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Odd cassette hub problem
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#10
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Odd cassette hub problem
On Fri, 27 Sep 2019 07:36:49 -0500, AMuzi wrote:
That's impressive but not what I saw then. The SARA units were uniform design, made of square channel and painted bright blue with SARA in white, each with different end tooling (punch, drill, press, grasp, etc) and very crude compared to modern units. Still amazing at that time. I guess that is relevant to anyones prior experience. The difference over time is accuracy and speed*. Their intial uses tends to be task by task; e,g replacing the person doing the spot welding or part bending. The amazing part of robots was outlined by an "engineer" whose experience included a car assembly line and whitegood production lines, when, in the early 70's, their new japanese overlords said "the assembly line will now change model production within two days and not the old 7-10 dys it previously took". *This same engineer said one of his first robot tasks was to show that the robot was acccurate and consistent and the assembly problem was the inconsistent hole puching in the parts to be assembled. Something about a scribe touching 20 points over and over again for 24 hours at full speed tended to counter all excuses that "robots are no good" |
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