slow-poke
Ultra Member
I just read the entire Gearhead88 lathe wiring saga. Hats of to you for sticking with it and finding the problem.
I have a BB CX706 lathe and had issues with the wiring. The diagram was wrong so I corrected and posted it in the link below, just in case anyone has to troubleshoot a CX706.
www.hobby-machinist.com
I get the sense that the people that wire these things up at the factory know enough to make it work but use the diagram more as a conceptual guide and wire them up as they please probably no two the same way. They swap hot and neutral, change the sequence of series components etc. This is tricky enough if you understand electrical wiring and frustrating as hell for those that dabble as required.
I'm pretty good with troubleshooting electrical issues and a few comments in all the suggestions resonated with me so I'm going to summarize them for the benefit of the dablers.
1) With electromechanical stuff like this 75% of the problems are actually mechanical, see Susquatch comment connections connections connections. As well as the comments about the iffy relays/contactors/switches/poor terminations, etc. On my CX706 some of the wires were just falling out of the crimped connectors.
2) If motor related and the motor has capacitors and it's humming but not spinning and you can safely give the motor a little spin to get it going and it then starts, change the capacitor(s). When I encounter a non working ac motor with capacitors, first thought is it's probably the capacitors (or the centrifugal switch). Electrolytic capacitors have a relatively short expected life typically in the 2000-6000 hour range and that's for a quality capacitor and the odds of a quality capacitor being factory installed in these BB commodity type products is about zero.
3) Ask yourself what am I assuming that seems logical but is incorrect. For example the motors not turning must be a bad motor. The wiring diagram shows this, is the diagram accurate?
4) make sure your test equipment including your test leads are working properly again don't assume verify, a flaky intermittent set of leads can send you in circles not to mention be hazardous.
5) Be safe, unplug the thing, discharge the capacitors if required and use a quality meter preferably with a legitimate CAT rating. Many of the MIC meters are simply outright dangerous for use with hazardous voltages. A new or used Fluke meter on eBay or Kijiji are often affordable and if fitted with the correct fuse are safe.
Know your limitations if this is not your area of expertise, get help don't assume that because you fixed a 120/240V circuit a few times you should be fine poking around in a 600V circuit. If someone offered me $10k to simply measure for the presence of 600V with one of those fake CAT rated meters I would pass, that's how dangerous they can be.
6) The divide and conquer technique can speed things up. Hmmm....The motor won't turn, do I have the correct voltage at the motor?
- yes, okay then I can probably ignore all the circuitry leading up to the motor and focus on the motor
- no, okay motor is probably okay, do I have the correct voltage at the output of the contactor? etc etc...
I have a BB CX706 lathe and had issues with the wiring. The diagram was wrong so I corrected and posted it in the link below, just in case anyone has to troubleshoot a CX706.
CX706 Wiring Diagram
Recently I had to play with the wiring in my CX706 lathe and found that the provided wiring diagram was very misleading. I don't know if they simply wired my particular unit in a significantly different fashion than the provided wiring diagram or they are all like this. I have provided the...
www.hobby-machinist.com
I get the sense that the people that wire these things up at the factory know enough to make it work but use the diagram more as a conceptual guide and wire them up as they please probably no two the same way. They swap hot and neutral, change the sequence of series components etc. This is tricky enough if you understand electrical wiring and frustrating as hell for those that dabble as required.
I'm pretty good with troubleshooting electrical issues and a few comments in all the suggestions resonated with me so I'm going to summarize them for the benefit of the dablers.
1) With electromechanical stuff like this 75% of the problems are actually mechanical, see Susquatch comment connections connections connections. As well as the comments about the iffy relays/contactors/switches/poor terminations, etc. On my CX706 some of the wires were just falling out of the crimped connectors.
2) If motor related and the motor has capacitors and it's humming but not spinning and you can safely give the motor a little spin to get it going and it then starts, change the capacitor(s). When I encounter a non working ac motor with capacitors, first thought is it's probably the capacitors (or the centrifugal switch). Electrolytic capacitors have a relatively short expected life typically in the 2000-6000 hour range and that's for a quality capacitor and the odds of a quality capacitor being factory installed in these BB commodity type products is about zero.
3) Ask yourself what am I assuming that seems logical but is incorrect. For example the motors not turning must be a bad motor. The wiring diagram shows this, is the diagram accurate?
4) make sure your test equipment including your test leads are working properly again don't assume verify, a flaky intermittent set of leads can send you in circles not to mention be hazardous.
5) Be safe, unplug the thing, discharge the capacitors if required and use a quality meter preferably with a legitimate CAT rating. Many of the MIC meters are simply outright dangerous for use with hazardous voltages. A new or used Fluke meter on eBay or Kijiji are often affordable and if fitted with the correct fuse are safe.
Know your limitations if this is not your area of expertise, get help don't assume that because you fixed a 120/240V circuit a few times you should be fine poking around in a 600V circuit. If someone offered me $10k to simply measure for the presence of 600V with one of those fake CAT rated meters I would pass, that's how dangerous they can be.
6) The divide and conquer technique can speed things up. Hmmm....The motor won't turn, do I have the correct voltage at the motor?
- yes, okay then I can probably ignore all the circuitry leading up to the motor and focus on the motor
- no, okay motor is probably okay, do I have the correct voltage at the output of the contactor? etc etc...
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