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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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Old Grob bandsaw.. no torque/ power
Hi all, our old bandsaw stopped working so well. It has no torque/ power
and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. George H. |
#2
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote:
Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. |
#3
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote:
On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH |
#4
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Ah, well, the running backwards strongly indicates it is running on single phase. Check the power switch/motor starter to make sure all 3 phases are connecting. Check any fuses. Look for loose/broken wires. Without knowing what sort of switch/motor starter it has, I can't get more detailed. It COULD be the motor, but could as likely be something external. Jon |
#5
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
wrote in message
... On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote: On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH You told us the symptoms, so what was the cause? We all started out clueless and had to learn somehow. |
#7
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
On 2019-07-31, wrote:
On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor Check the three voltages -- and check the three cartridge fuses. Good Luck, DoN. -- Remove oil spill source from e-mail Email: | (KV4PH) Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
#8
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
On Wednesday, July 31, 2019 at 3:44:32 PM UTC-4, Jim Wilkins wrote:
wrote in message ... On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote: On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH You told us the symptoms, so what was the cause? We all started out clueless and had to learn somehow. Oh sorry, one (or two) of the phases was missing. Someone had been abusing the power plug into the wall outlet... Five minutes with a screwdriver and all was good. George H. |
#9
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
wrote in message
... On Wednesday, July 31, 2019 at 3:44:32 PM UTC-4, Jim Wilkins wrote: wrote in message ... On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote: On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH You told us the symptoms, so what was the cause? We all started out clueless and had to learn somehow. Oh sorry, one (or two) of the phases was missing. Someone had been abusing the power plug into the wall outlet... Five minutes with a screwdriver and all was good. George H. I've been troubleshooting electronics since 1970. It's rare for the problem to be other than a bad connection. At the Fort Monmouth Army school the instructors heated and removed an end cap from glass tube fuses and inserted too-short heavy bus wire or paper tags with "good fuse" on them, to teach us to check the power first, and test fuses with an ohmmeter. |
#10
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
On Thursday, August 1, 2019 at 3:07:38 PM UTC-4, Jim Wilkins wrote:
wrote in message ... On Wednesday, July 31, 2019 at 3:44:32 PM UTC-4, Jim Wilkins wrote: wrote in message ... On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote: On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH You told us the symptoms, so what was the cause? We all started out clueless and had to learn somehow. Oh sorry, one (or two) of the phases was missing. Someone had been abusing the power plug into the wall outlet... Five minutes with a screwdriver and all was good. George H. I've been troubleshooting electronics since 1970. It's rare for the problem to be other than a bad connection. Grin... Well someone else here found the problem and 'assumed' a bad cap. after a day I was brought it to help... I sorta bought into to the 'bad cap' idea. At the Fort Monmouth Army school the instructors heated and removed an end cap from glass tube fuses and inserted too-short heavy bus wire or paper tags with "good fuse" on them, to teach us to check the power first, and test fuses with an ohmmeter. I've been thinking of some sort of trouble shooting guide for people. It seems like a common mistake is assuming the problem is the first thing you think of. And then you follow that idea down some rabbit hole. The first thing to do when trouble shooting is to think of all the things it could be. Make a list if you have to. Then start by checking all the simple things on the list. (simple as in simple to test.) Hmm, well and get lots of data on the problem, that's important. I do trouble shooting on the phone/ email every week or two... you learn to ask a lot of questions. George H. |
#11
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Old Grob bandsaw.. no torque/ power
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#12
Posted to rec.crafts.metalworking
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Old Grob bandsaw.. no torque/ power
wrote in message
... On Thursday, August 1, 2019 at 3:07:38 PM UTC-4, Jim Wilkins wrote: wrote in message ... On Wednesday, July 31, 2019 at 3:44:32 PM UTC-4, Jim Wilkins wrote: wrote in message ... On Wednesday, July 31, 2019 at 12:35:28 PM UTC-4, wrote: On Wednesday, July 31, 2019 at 12:29:28 PM UTC-4, wrote: Hi all, our old bandsaw stopped working so well. It has no torque/ power and when you turn on the unloaded motor it sometimes runs backwards. The thought here is that maybe a start or run capacitor had gone bad... but we are all mostly clueless when it comes to motors. Any ideas before I try and get the motor out. (Oh dear.. I think it's a three phase motor... (no cap)) Maybe check the three voltages? Or a bad motor George H. Never mind. problem fixed. (Sometimes all I need is a smart audience.) GH You told us the symptoms, so what was the cause? We all started out clueless and had to learn somehow. Oh sorry, one (or two) of the phases was missing. Someone had been abusing the power plug into the wall outlet... Five minutes with a screwdriver and all was good. George H. I've been troubleshooting electronics since 1970. It's rare for the problem to be other than a bad connection. Grin... Well someone else here found the problem and 'assumed' a bad cap. after a day I was brought it to help... I sorta bought into to the 'bad cap' idea. At the Fort Monmouth Army school the instructors heated and removed an end cap from glass tube fuses and inserted too-short heavy bus wire or paper tags with "good fuse" on them, to teach us to check the power first, and test fuses with an ohmmeter. I've been thinking of some sort of trouble shooting guide for people. It seems like a common mistake is assuming the problem is the first thing you think of. And then you follow that idea down some rabbit hole. The first thing to do when trouble shooting is to think of all the things it could be. Make a list if you have to. Then start by checking all the simple things on the list. (simple as in simple to test.) Hmm, well and get lots of data on the problem, that's important. I do trouble shooting on the phone/ email every week or two... you learn to ask a lot of questions. George H. When a student asked if there was a troubleshooting procedure the answer was yes, but since it covered every possibility it took far too long to run through. They said they'd found that teaching students how the circuits operated in detail resulted in much shorter downtimes of the communications links we supported. That worked for them as long as the Vietnam draft brought in science and engineering grads with the aptitude and (more importantly) the patience to learn complex systems. After it ended they had to downgrade to board-swapping. |
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