Great vid Halligan. I rebuild these all the time. I get 20 or 30 given to me every year. Its fun to get them back into service and your vid is a great instructional tool for the inexperienced. I look forward to the next one.
Thanks so much for making this video. Today i got the motor on my 1951 Craftsman Table Saw working!!! This video, and others like it, helped me diagnose and fix my 3/4 single phase Ajax motor. Thanks Again! Great video!
Hi Greg. Exactly what I did about 3 weeks ago with a similar size motor for a wood lathe. In my case when I got to the rear bearing (enclosed like yours), I packed the void with grease and found a close tolerance sliding fit shaft. Entering into the hole in the bearing and hit with a hammer to 'hydraulically' press the bearing out from behind. Maybe refill with grease as some air will be trapped, but a couple of go's and it will come out without needing to drill the 2 holes. Mark in the UK
@ 5:30, use grease to fill the area behind the bearing and use either the shaft or a dowel through the center hole to rapidly compress (AKA smack with a hammer) the grease pushing the bearing out.
I did a rewind of a single phase coal heat distributor last summer, was really fun :P I did the standard repairs on 20+ other motors during the summers including switching capacitors and bearings, best job I have tried so far
ooops, forgot to mention. The 110VAC on your capacitor indicates a MAXIMUM WORKING voltage. So, when replacing always be sure to replace with a working voltage rating of AT LEAST the voltage that the motor will be running on. As a general rule, ANY capacitor, paper, ceramic, electrolytic, tantalum etc., will have a MAXIMUM WORKING VOLTAGE RATING. Keep these great videos coming. Mark in the UK
~RE: at 8:05 on the clip. The main reason for this gradual (dual) bearing failure is that a single seal bearing is being used (refered to on the bearing as a single 'Z'). Either use double seal ('ZZ') or rubber seal (2RS). Either of these double seal type bearings will prevent dust ingress to the bearings so replacing with a single seal bearing will just cause headaches down the line. ~Regarding the internal centrifugal starting switch... Other than cleaning the contacts, (good idea), over time the pressure ring will flatten slightly so it's always a good idea to bend the ring out slightly, this will ensure a solid contact when the switch drops back into circuit at low rpm. ~Regarding the discharge resistor... these aren't necessary with starting capacitors due to the low MDF rating, the residual voltage in the starting capacitor will be minimal at best but always use the resistor if it is a running capacitor as these WILL hold a kick (low MFD). The μ symbol you questioned is just the international symbol for 'micro' so the capacitors will either show for instance: 60MFD or 60μF, both just mean 60 micro Farads. The VAC you refered to is Volts AC or volts (alternating current). ~One last point, before you run test the motor you should megger test it to ensure that your windings don't have earthing problems, quite important as you generally would not know the integrity or condition of the coil slot liners (slot insulation) purely by visual inspection. You grabbed the motor whilst it was running without doing this basic pre-run test, this could prove fatal if there had of been an earth fault.
incorrect: the bearing almost always come with two seals, even though they put a single Z at each seal. this is what they do. and they don't do a single-seal bearings - you can always remove one seal and you get a 'single Z' bearing. and the whole process is still cheaper than having to construct two production lines, one for Z and the other for ZZ. I believe this guy has used bearings with seals on both sides. this is a standard.
Nice vid. Switch the 2 starting leads to rev rotation. 6202 is a common metric brng, it's said "sixty-two, O, two". It's a 6200 series brng. 6000, 6100, 6200, etc. I have lots of dual volt motors here wired for 220v that have 110v cap for starting in them. It's such a brief time they are energized it doesn't seem to bother them. Single voltage motors can be opened and rewired higher or lower by tracing the windings and can always put a HD DPDT 250V switch for reversing the starting leads.
Greg, thanks for helping me to understand how electric motors are wired and function. They have always been a big mystery to me. Electrically challenged. Michael
cont. from below: with a punch mark, 1 and 2 punches so it's easy to put back together. It sounds like you're handling it well, just some additional info. If you did have loose rotor bars, it would be hard starting the machine. You do great work, btw :)
They make a motor tester that ouputs a pulse for ringing to check for shorted turns for that stator, but it's an expensive machine better suited for large motors for industrial use. Generally, shorted turns on the stator causes localized heating, pretty subjective to test for. Use a growler to test for open rotor bars, and usually just burnish the starting switch contacts unless it's burnt bad. The color of the windings tell you a lot. BTW, we usually mark the end bells and the stator housing.
The squiggly letter on the meter you showed us is , i believe, the greek letter omega designating ohms or resistance. In electricity it indicates current flow. Nice video, by the way. Resistors limit the flow of current.
The next time you have to get a blind bearing out, fill it with grease and use a tight fitting punch. It's messy, but they will usually come right out. I agree with the guys about marking the end bells, like to do it before I even remove any bolts.
Nice video . again! :) Just a tip - capacitor could be made longer by gluing a chopped off piece of the old - onto the new one. With Tec7, or similar..
Awesome vid, quick point on removing the bearing inside the housing. I use a small dremel cut wheel to saw a small slice in the bearing, this will reduce the tension and allow the bearing to fall out of the housing.
Great channel, most enjoyable!! On the 1/2 dual voltage motor: Either you got lucky, or you did not show the phasing of the main windings. If they are out of phase the motor will not start, and you will probably blow a breaker. To test, connect only one of the main windings at a time, and try starting. If there is enough torque to start, do the same to the other winding and check rotation. If it is reverse rotating, just reverse the leads to that main. On 208/220, it is harder because they are in series and you need both connected. If they are not in phase, you will not start or the breaker will blow. Reverse one of the main series windings. Lot of words, but, in fact, that is what you have to do on a dual voltage motor. Thanks again!!
That's a cool old motor! I'm curious what keeps the stator in center, inside the shell? It looks like it's loose when the motor is disassembled. One more point, with the capacitor discharge resistors. They also help prolong the life of the centrifugal switch contacts. Motors in an application with very short run cycles can start, stop and close the switch with a charge still on the capacitor. Making sure the caps are discharged before the motor stops (and the centrifugal switch closes) will help with the pitting.
I don't believe there's any evidence that proves bleed resistors "help prolong the life of the centrifugal switch contacts". In some applications, they're put in place to stop something known as regeneration; where the capacitor discharges while winding down as the motor passes from the run winding to the start winding creating a shuddering effect as the motor tries to restart.
jrmym2 Sure there is. I (c) = c dv/dt. R makes sure you don't change v in 0 time. Z= 1/CS parallel with R, where S = J w, w=2pi f, if memory is correct.
Nice demo! One thing I learned was you mentioned "Motor cleaner" and I saw how clean you got those windings.. I think the copper windings are still coated with shellac and that shellac will dissolve with alcohol so I never knew how to clean windings until seeing your video. So do you use something like the CRC electronic cleaner or do you have another product? I saw an "Electric Motor Cleaner" (spray) but that was for RC motors...
Great video, very informative!! Wish the grime was wiped off the table haha But seriously, I've learned as much from this as I have with any other vid I've watched on dual voltage motors!! Thanks!
I buy my small bearings from Accurate Bearing Company in chicago they have great prices, also I usually always get the sealed bearings instead of the shielded type.
Hey Greg something occurred to me that could be a valued addition to this video for clarification. It is crucial that the main windings be phased correctly! Perhaps you could add some text to this video indicating the relevance to a 6 wire capacitor start motor.
Great video! It would have been nice to see more of the wiring connections. When you said "all you have to do to reverse the motor direction was to switch the capacitor leads". Does that apply to all motors with a centrifugal switch? Also if I connect the wiring to a double pole double throw DPDT switch can it reverse on demand? Of course the central switch wiring will be crossing over to change polarity direction. thanks
It applies to most motors. Each one can be slightly different in the wiring numbers especially if you have one made before NEMA standards. Also most motors are not instant reverse. My lathe is an exception, but it contains an extra relay for this purpose. For a regular motor you would have to wait for the motor to slow down and the centrifugal switch to close before it can be reversed otherwise it will continue in the same direction.
"VAC" stands for Volts AC, basically meaning the maximum voltage a capacitor can handle. So any "VAC" equal or higher than your application will do nicely. The Greek letter "μ" is used as a symbol for 'micro' meaning divided by a 1000 000. So, 341 MFD or 341 μF stands for 341 micro Farad or 341/1000 000 Farad.
ok good video . When you were testin to see which wires go together did you check for ohms thru the 2 wires?? I am trying to rewire a single phase 110v and 220v ac motor on a Grizzly milling machine. I am not ready to install 220v line to my gagrage yet so Imtrying to use the 110v configuration. Can you give me some advice. Thanks Manny PS get back to machining :))
Manny Monroy If it's the original motor there should be a diagram on there or if not at least one in the manual. Have a peek here may point you in the right direction. ijyam.blogspot.com/2011/07/internal-wiring-configuration-for-dual.html
Where can I order bearings for an old Westinghouse 1/2Hp 115v from an belt drive attic exhaust fan? Is there a cross reference to motors made 50 years ago ? Thanks.
You made my day with this. I'm in the process of rebuilding a Shopsmith 10E and the motor it came with needs pretty much the exact rebuild you describe here. One question - how did you fit the bearings back into the housing? Did you have to heat the backplate, or were you able to just press fit them on cold? I noticed you put the bearings on the shaft first - was there any concern of them shifting as you pressed them on to the housing plates?
The bearings are a hard press fit on the shaft and a light press in the end bell housings. The bearings seat into a shoulder on the shaft so there isn't an issue of them shifting when reinstalling the housing. You can tap the housings onto the bearings with a non marring hammer and then turn the housings to the correct positions and bolt together.
Good job ! Couple questions: where are the brushes?? You did not replace them?? Thanks, just wondering....=), and ps. Where did you buy new bearings?? Ebay? Thanks=)
This is an induction motor so no brushes. The bearings were bought from a local vendor. You can find many places online for bearings, but the New Departure brand bearings are no longer made and have an extended inner race so you'd have to track down NOS ones like I did or get the equivalent standard bearing and then make a spacer.
I have an old craftsman. I did exactly what you did but when I plug it in It tripped the breaker? Double and triple checked the wiring. Any suggestions?
This was great, lots of useful info. I would like to have seen how you get bearings on and off shaft and/or motor housing. I have question whether it is OK to bang on the shaft with a hammer, or could that demagnetize the core magnets (if such perm magnets exist)? I wanted to rebuild a 1/2 HP washing machine motor, but the housing cannot be taken apart, it seems to be two pieces epoxied together. I went ahead and hacksawed through the housing at each end to get to the bearings, but I'm not sure how to get the bearings out. Would like to see that. I had tried previously to oil the bearings before I understood the concept of sealed bearings. What I accomplished was lubing the shaft so it turned easily inside the inner bearing surface (race?). So actually I created the illusion of making a stuck motor rotate easily again. My question there is: should bearings be tightly fixed on the shaft somehow, or is it OK for the bearing to just slide over the shaft with low friction. It seems that would make two bearing surfaces, one on the shaft and outer race, and the other inside the bearing where the balls are. Does oiling the shaft in that way actually cause a bad condition? I'm going to see if I can drill, shim, and screw the hacksawed housing back together. I doubt I can restore the perfect alignment needed, just for the heck of it I may try. It seems like a real waste that these motors, which can retail for $240, are "throwaway" parts because you can't open them up properly. I had seen the centrifugal start motor switch but didn't know what it was, thanks for identifying it.
+Simon Baker That really sucks they make it so you can't rebuild the motor, but just for general knowledge, The bearings do want to have a tight fit to the shaft, and to the housing. If they spin on the shaft, or in the housing, they will get very hot, and eventually ruin the shaft or housing seat. Some can be banged off or out, but you need to hold a block of wood on the end of the shaft and hit that with the hammer so you don't mushroom the end of the shaft. If you don't get it to move after a wack or two, don't keep beating on it, if they are very tight you need to use a bearing puller or a press. A lot of car parts places let you borrow tools for free, they have a puller you can borrow.
+C Smith Thanks for reply! I think I learned some more about these "non-serviceable" motors. I pried apart the bearings and they don't seem to be ball bearing design at all. I think they are simple "lubed sleeve" design, which is just a lubed cylinder in which the shaft rotates. There seems to be a lube reservoir surrounding the cylindrical sleeve which is stuffed with an absorbent material that looks like a felt pad. They are pretty dried out, with some thick grease residue left in places. The two bearings are not identical, I think for "self-alignment" purposes -- because one bearing is basically a "swivel ball" with a cylindrical hole in it that the shaft goes through. The "swivel ball" is held by a press-fit piece of metal with a cavity that holds the "swivel ball" (my terminology -- I'm not a mech engineer). This seems to allow one of the bearings to adjust to the angle of the rotor shaft to minimize friction and achieve best alignment. That's my guess. The other bearing is just a fixed cylindrical polished sleeve press-fit into a cylindrical cavity in the motor housing I think. I think it may be perfectly feasible to lube these bearings if you drilled small holes in the press-fit reservoir/bushings that make up the bearings and inject some kind of lube, then plug the holes. Doing that every 5 years might keep these motors running a lot longer, don't know. I find the idea of "extreme repair" / "bush fix" interesting, so I'll keep thinking of ways that these weird bearings might be replaced by conventional ball bearings to salvage these motors if all else is in good shape. But given the design of the housing, it looks very challenging to make some kind of bushing to hold the bearings solidly, and probably a real witch to get perfect alignment. Probably would need to weld in a new piece of metal, etc. But probably there is some clever minimal way to do it -- especially if you had no other choice (WWII pilot stranded needs to fix generator, etc.).
I have a Dayton 3/4 hp single phase (6K376BA) that I want to change rotation on. Can you link me to a video you may have made to do that or another you would recommend? Also I need an end plate to cover the wiring access if you might know where I could get one please? Thank you for making and sharing your video! Mac
Is the motor plate intact? If it is there is a wiring diagram on there that shows to switch 2 wires. You'll have to search online for the wiring cover. There are a few places around that stock motor parts such as centrifugal switches. They may have something.
The motor plate is intact but all the wires are numbered with no other reference. I'll check with centrifugal switches for the wiring cover. Thank You.
Victor Plawski First and easiest to check is the bearings. If the shaft doesn't spin free then there's your problem. Next up would be the capacitor. Check for leaks. If it looks like crap just replace it. They're cheap. Next up is the centrifugal switch contacts. Clean them and make sure the switch functions and the springs and everything move.
I have an old, old 1/3 hp motor off an old Delta drill press. It wouldn't start on its own. I suspected the starter capacitor was bad but it checks good. Have any idea's as to what's ailing it?
If it's not the capacitor I'd have a look at the centrifugal switch. Could very well be that the switch has a lot of carbon build up from arcing and is not making good contact. Give the contacts a light sand with some emery and make sure they close.
Hi. I have an old 1950s 3/4 horsepower craftsmen start capacitor motor that came off a table saw. I am rebuilding it and the motor worked just fine before I took the bearings off and replaced them when I put it all back together it just humms and won’t spin also the shaft gets stiff and won’t spin but when I shut everything off the shaft will spin again. Can you tell me does this have anything to do with maybe the capacitor being bad or should I check something else?
Hi, I was wondering if you could help me out with a wiring issue im having. I have a motor that is 115/230v 3/4 hp that i just bought from a salvage yard for my bench top mill and am not sure how to wire it in. It had 3 wires coming out of the back of it; black, white, and green. the green went to a ground screw so thats easy, then it was white and black so i assumed it was setup for 115 v so i wired it in that way and the motor fires up no problem. the problem is that it doesnt seem to have the power that it should and I was curious if maybe it was already setup as 230 and I have it set up as 115. if thats the case would the motor even work if i wired it to 115 and it was supposed to be 230? It has a motor plate but no schematic or anything about switching the power around. any help would be appreciated. I also noticed the part in your video also when you said the motor wasnt getting hot, mine gets warm fast when i turn it on so thats what made me start thinking i have something wrong too.
Does the nameplate say 115/230? If so, only a black and white makes no sense, because there would be no way to change the voltage setup. Getting warm fast on 115 probably means there is something wrong with the motor. If the starting switch is not opening, that would make it get hot very fast. I think you might have a dud.
larry brunetti, yes the name plate does say 115/230 and there are a few terminals inside the motor you can change the wire positions around to. There is no wiring diagram nor could I find one online. I assumed it was wired 115 so that's the way I hooked it up. I not familiar with them enough to know whether or not it would even work if it's setup for 230 and I wired it to 115. I was thinking maybe it was getting hot and doesn't have much power because it's missing the other power leg and only half the windings are being energized?
Chris, out of the motor there will be 6 wires. Two for the starting winding, and the other pair for the main windings. For 230 v operation, the main windings will be connected in series, and the staring winding will be across ONE of the staring windings. For 115 v operation, the starting windings will be in parallel, with the starting winding across BOTH of them. In both cases, the main windings must be phased, as I described in the article above. If the motor starts on 115, but is weak, it is probably wired for 230, and if it doesn’t get up to speed, the starting winding will not kick out and the motor will get hot and draw a lot of current. Either try it on 230, or rewire it according to my article. If you take all of the wires apart, you can use an ohmmeter to check the coils out. You can get an ohmmeter at NAPA, True Value Hardware or Radio Shack: the main windings will be the same resistance the starting winding will be different than the mains. Phase the mains, and connected as I described. Should have no problem. Good Luck!
hi thnx for your nice movie I am looking for a movie that shows when coils are ruined how we can distinguish and how can we repair it .....what are the scientific back ground and more ...how can you help me?
Hi Mr. H. I have an old 1947 drillpress the motor is weak, I have to hand-spin it to get it going, and on the fastest belt - it just hums.. "1/2 Horsepower Ball bearing 1750 RPM, 115 volts 60 cycle 6.7 AMP. Type CNB K8 Model 1156962. Is this something an amatuer can rebuild? I'd really like to get this running better. Thanks for any advice. ruclips.net/video/vUtktQjmJzA/видео.html
Yes relatively easy to take apart. More than likely the crease in the bearings has turned to peanutbutter. You can replace them or try to clean and regrease if they don't have seals.
Great vid Halligan. I rebuild these all the time. I get 20 or 30 given to me every year. Its fun to get them back into service and your vid is a great instructional tool for the inexperienced. I look forward to the next one.
Thanks so much for making this video. Today i got the motor on my 1951 Craftsman Table Saw working!!! This video, and others like it, helped me diagnose and fix my 3/4 single phase Ajax motor. Thanks Again! Great video!
Glad it helped!
Hi Greg. Exactly what I did about 3 weeks ago with a similar size motor for a wood lathe. In my case when I got to the rear bearing (enclosed like yours), I packed the void with grease and found a close tolerance sliding fit shaft. Entering into the hole in the bearing and hit with a hammer to 'hydraulically' press the bearing out from behind. Maybe refill with grease as some air will be trapped, but a couple of go's and it will come out without needing to drill the 2 holes. Mark in the UK
Real good info. Just what i was searching for no tags or marking on a Atlas 1940s motor thank you
@ 5:30, use grease to fill the area behind the bearing and use either the shaft or a dowel through the center hole to rapidly compress (AKA smack with a hammer) the grease pushing the bearing out.
Yup, I remember that trick from a long time ago. I didn't believe it until I tried it. I used a dowel and it took a few whacks to get it out.
I did a rewind of a single phase coal heat distributor last summer, was really fun :P I did the standard repairs on 20+ other motors during the summers including switching capacitors and bearings, best job I have tried so far
ooops, forgot to mention. The 110VAC on your capacitor indicates a MAXIMUM WORKING voltage. So, when replacing always be sure to replace with a working voltage rating of AT LEAST the voltage that the motor will be running on. As a general rule, ANY capacitor, paper, ceramic, electrolytic, tantalum etc., will have a MAXIMUM WORKING VOLTAGE RATING. Keep these great videos coming. Mark in the UK
~RE: at 8:05 on the clip. The main reason for this gradual (dual) bearing failure is that a single seal bearing is being used (refered to on the bearing as a single 'Z'). Either use double seal ('ZZ') or rubber seal (2RS). Either of these double seal type bearings will prevent dust ingress to the bearings so replacing with a single seal bearing will just cause headaches down the line.
~Regarding the internal centrifugal starting switch... Other than cleaning the contacts, (good idea), over time the pressure ring will flatten slightly so it's always a good idea to bend the ring out slightly, this will ensure a solid contact when the switch drops back into circuit at low rpm.
~Regarding the discharge resistor... these aren't necessary with starting capacitors due to the low MDF rating, the residual voltage in the starting capacitor will be minimal at best but always use the resistor if it is a running capacitor as these WILL hold a kick (low MFD). The μ symbol you questioned is just the international symbol for 'micro' so the capacitors will either show for instance: 60MFD or 60μF, both just mean 60 micro Farads. The VAC you refered to is Volts AC or volts (alternating current).
~One last point, before you run test the motor you should megger test it to ensure that your windings don't have earthing problems, quite important as you generally would not know the integrity or condition of the coil slot liners (slot insulation) purely by visual inspection. You grabbed the motor whilst it was running without doing this basic pre-run test, this could prove fatal if there had of been an earth fault.
incorrect: the bearing almost always come with two seals, even though they put a single Z at each seal. this is what they do. and they don't do a single-seal bearings - you can always remove one seal and you get a 'single Z' bearing. and the whole process is still cheaper than having to construct two production lines, one for Z and the other for ZZ. I believe this guy has used bearings with seals on both sides. this is a standard.
I love the Adjustable Hammer !!
Nice vid. Switch the 2 starting leads to rev rotation. 6202 is a common metric brng, it's said "sixty-two, O, two". It's a 6200 series brng. 6000, 6100, 6200, etc. I have lots of dual volt motors here wired for 220v that have 110v cap for starting in them. It's such a brief time they are energized it doesn't seem to bother them. Single voltage motors can be opened and rewired higher or lower by tracing the windings and can always put a HD DPDT 250V switch for reversing the starting leads.
Great video!! I always love seeing electrical starters and motors rebuilt!
Greg, thanks for helping me to understand how electric motors are wired and function. They have always been a big mystery to me. Electrically challenged.
Michael
cont. from below: with a punch mark, 1 and 2 punches so it's easy to put back together. It sounds like you're handling it well, just some additional info. If you did have loose rotor bars, it would be hard starting the machine. You do great work, btw :)
They make a motor tester that ouputs a pulse for ringing to check for shorted turns for that stator, but it's an expensive machine better suited for large motors for industrial use. Generally, shorted turns on the stator causes localized heating, pretty subjective to test for. Use a growler to test for open rotor bars, and usually just burnish the starting switch contacts unless it's burnt bad. The color of the windings tell you a lot. BTW, we usually mark the end bells and the stator housing.
The squiggly letter on the meter you showed us is , i believe, the greek letter omega designating ohms or resistance. In electricity it indicates current flow. Nice video, by the way. Resistors limit the flow of current.
The next time you have to get a blind bearing out, fill it with grease and use a tight fitting punch. It's messy, but they will usually come right out. I agree with the guys about marking the end bells, like to do it before I even remove any bolts.
I love my crescent hammer set too!!! LOL. Enjoyed the lesson. Thank you.
Great vid, thanks for posting. Please make vids that show how the wiring is setup up and why.
robviolin1 I do for this particular motor at ~ 12:30
Nice video . again! :) Just a tip - capacitor could be made longer by gluing a chopped off piece of the old - onto the new one. With Tec7, or similar..
Awesome vid, quick point on removing the bearing inside the housing. I use a small dremel cut wheel to saw a small slice in the bearing, this will reduce the tension and allow the bearing to fall out of the housing.
Great channel, most enjoyable!! On the 1/2 dual voltage motor: Either you got lucky, or you did not show the phasing of the main windings. If they are out of phase the motor will not start, and you will probably blow a breaker. To test, connect only one of the main windings at a time, and try starting. If there is enough torque to start, do the same to the other winding and check rotation. If it is reverse rotating, just reverse the leads to that main. On 208/220, it is harder because they are in series and you need both connected. If they are not in phase, you will not start or the breaker will blow. Reverse one of the main series windings. Lot of words, but, in fact, that is what you have to do on a dual voltage motor.
Thanks again!!
Excellent video, thank you for the info!
Awesome Greg. You give me hope since I usually destroy electric motors when attempting to fix them ;-)
16mm bore bearing can be found at Tractor Supply, FYI if anyone else has a similar build.
That's a cool old motor! I'm curious what keeps the stator in center, inside the shell? It looks like it's loose when the motor is disassembled.
One more point, with the capacitor discharge resistors. They also help prolong the life of the centrifugal switch contacts. Motors in an application with very short run cycles can start, stop and close the switch with a charge still on the capacitor. Making sure the caps are discharged before the motor stops (and the centrifugal switch closes) will help with the pitting.
I don't believe there's any evidence that proves bleed resistors "help prolong the life of the centrifugal switch contacts". In some applications, they're put in place to stop something known as regeneration; where the capacitor discharges while winding down as the motor passes from the run winding to the start winding creating a shuddering effect as the motor tries to restart.
jrmym2
Sure there is. I (c) = c dv/dt. R makes sure you don't change v in 0 time. Z= 1/CS parallel with R, where S = J w, w=2pi f, if memory is correct.
Don Gore Yeah right , that's what I was going to say...Just kidding : - )
Ken....this is so interesting and I don't have a clue.
Nice demo! One thing I learned was you mentioned "Motor cleaner" and I saw how clean you got those windings.. I think the copper windings are still coated with shellac and that shellac will dissolve with alcohol so I never knew how to clean windings until seeing your video. So do you use something like the CRC electronic cleaner or do you have another product? I saw an "Electric Motor Cleaner" (spray) but that was for RC motors...
Great instructional video. Thanks for posting.
Great video, very informative!! Wish the grime was wiped off the table haha But seriously, I've learned as much from this as I have with any other vid I've watched on dual voltage motors!! Thanks!
I saw enough to do a switch clean & cap. repl. on a bushing motor. Smoke or no smoke = we'll see?
Could you use some heat shrink tube around the cloth insulation?
I buy my small bearings from Accurate Bearing Company in chicago they have great prices, also I usually always get the sealed bearings instead of the shielded type.
What a coincidence, my old Hoover 3/4hp motor died and blew the capacitor . Going to try exactly what you've just done .
Hey Greg something occurred to me that could be a valued addition to this video for clarification. It is crucial that the main windings be phased correctly! Perhaps you could add some text to this video indicating the relevance to a 6 wire capacitor start motor.
Great video! It would have been nice to see more of the wiring connections. When you said "all you have to do to reverse the motor direction was to switch the capacitor leads". Does that apply to all motors with a centrifugal switch? Also if I connect the wiring to a double pole double throw DPDT switch can it reverse on demand? Of course the central switch wiring will be crossing over to change polarity direction. thanks
It applies to most motors. Each one can be slightly different in the wiring numbers especially if you have one made before NEMA standards. Also most motors are not instant reverse. My lathe is an exception, but it contains an extra relay for this purpose. For a regular motor you would have to wait for the motor to slow down and the centrifugal switch to close before it can be reversed otherwise it will continue in the same direction.
Pretty cool. What was the motor originally used in? It looked pretty old.
Good vid, one thing tho, it's not a rebuild, it's a repair. A rebuild is all you did plus rewinding
"VAC" stands for Volts AC, basically meaning the maximum voltage a capacitor can handle. So any "VAC" equal or higher than your application will do nicely.
The Greek letter "μ" is used as a symbol for 'micro' meaning divided by a 1000 000.
So, 341 MFD or 341 μF stands for 341 micro Farad or 341/1000 000 Farad.
Thumbs up, what is the name of the patient, I could see the letters KC on the side but it would be wonderful to know what you were working on.
ok good video . When you were testin to see which wires go together did you check for ohms thru the 2 wires??
I am trying to rewire a single phase 110v and 220v ac motor on a Grizzly milling machine. I am not ready to install 220v line to my gagrage yet so Imtrying to use the 110v configuration. Can you give me some advice.
Thanks
Manny
PS
get back to machining :))
Manny Monroy If it's the original motor there should be a diagram on there or if not at least one in the manual. Have a peek here may point you in the right direction. ijyam.blogspot.com/2011/07/internal-wiring-configuration-for-dual.html
Bleed resistor keeps the contacts from arcing on the start switch
Great video as always.
one4stevo
Where can I order bearings for an old Westinghouse 1/2Hp 115v from an belt drive attic exhaust fan? Is there a cross reference to motors made 50 years ago ? Thanks.
How did you get the rotor to center? I have 3/4 horsepower motor with a similar construction but i can get the rotor to not rub when reassembled
A cats head it a tube with screws in the side so you can run an odd shaped piece in a steady rest
Just wondering were you got the capacitor? I'm looking for a rather small one -- 53-64 mfd. also, what's a cats head?
You made my day with this. I'm in the process of rebuilding a Shopsmith 10E and the motor it came with needs pretty much the exact rebuild you describe here.
One question - how did you fit the bearings back into the housing? Did you have to heat the backplate, or were you able to just press fit them on cold? I noticed you put the bearings on the shaft first - was there any concern of them shifting as you pressed them on to the housing plates?
The bearings are a hard press fit on the shaft and a light press in the end bell housings. The bearings seat into a shoulder on the shaft so there isn't an issue of them shifting when reinstalling the housing. You can tap the housings onto the bearings with a non marring hammer and then turn the housings to the correct positions and bolt together.
Good job ! Couple questions: where are the brushes?? You did not replace them?? Thanks, just wondering....=), and ps. Where did you buy new bearings?? Ebay? Thanks=)
This is an induction motor so no brushes. The bearings were bought from a local vendor. You can find many places online for bearings, but the New Departure brand bearings are no longer made and have an extended inner race so you'd have to track down NOS ones like I did or get the equivalent standard bearing and then make a spacer.
I have an old craftsman. I did exactly what you did but when I plug it in It tripped the breaker? Double and triple checked the wiring. Any suggestions?
Great video ! Thank You !
This was great, lots of useful info. I would like to have seen how you get bearings on and off shaft and/or motor housing. I have question whether it is OK to bang on the shaft with a hammer, or could that demagnetize the core magnets (if such perm magnets exist)?
I wanted to rebuild a 1/2 HP washing machine motor, but the housing cannot be taken apart, it seems to be two pieces epoxied together. I went ahead and hacksawed through the housing at each end to get to the bearings, but I'm not sure how to get the bearings out. Would like to see that.
I had tried previously to oil the bearings before I understood the concept of sealed bearings. What I accomplished was lubing the shaft so it turned easily inside the inner bearing surface (race?). So actually I created the illusion of making a stuck motor rotate easily again. My question there is: should bearings be tightly fixed on the shaft somehow, or is it OK for the bearing to just slide over the shaft with low friction. It seems that would make two bearing surfaces, one on the shaft and outer race, and the other inside the bearing where the balls are. Does oiling the shaft in that way actually cause a bad condition?
I'm going to see if I can drill, shim, and screw the hacksawed housing back together. I doubt I can restore the perfect alignment needed, just for the heck of it I may try. It seems like a real waste that these motors, which can retail for $240, are "throwaway" parts because you can't open them up properly.
I had seen the centrifugal start motor switch but didn't know what it was, thanks for identifying it.
+Simon Baker
That really sucks they make it so you can't rebuild the motor, but just for general knowledge,
The bearings do want to have a tight fit to the shaft, and to the housing.
If they spin on the shaft, or in the housing, they will get very hot, and eventually ruin the shaft or housing seat.
Some can be banged off or out, but you need to hold a block of wood on the end of the shaft and hit that with the hammer so you don't mushroom the end of the shaft.
If you don't get it to move after a wack or two, don't keep beating on it, if they are very tight you need to use a bearing puller or a press.
A lot of car parts places let you borrow tools for free, they have a puller you can borrow.
+C Smith Thanks for reply! I think I learned some more about these "non-serviceable" motors. I pried apart the bearings and they don't seem to be ball bearing design at all. I think they are simple "lubed sleeve" design, which is just a lubed cylinder in which the shaft rotates. There seems to be a lube reservoir surrounding the cylindrical sleeve which is stuffed with an absorbent material that looks like a felt pad. They are pretty dried out, with some thick grease residue left in places. The two bearings are not identical, I think for "self-alignment" purposes -- because one bearing is basically a "swivel ball" with a cylindrical hole in it that the shaft goes through. The "swivel ball" is held by a press-fit piece of metal with a cavity that holds the "swivel ball" (my terminology -- I'm not a mech engineer). This seems to allow one of the bearings to adjust to the angle of the rotor shaft to minimize friction and achieve best alignment. That's my guess. The other bearing is just a fixed cylindrical polished sleeve press-fit into a cylindrical cavity in the motor housing I think.
I think it may be perfectly feasible to lube these bearings if you drilled small holes in the press-fit reservoir/bushings that make up the bearings and inject some kind of lube, then plug the holes. Doing that every 5 years might keep these motors running a lot longer, don't know.
I find the idea of "extreme repair" / "bush fix" interesting, so I'll keep thinking of ways that these weird bearings might be replaced by conventional ball bearings to salvage these motors if all else is in good shape. But given the design of the housing, it looks very challenging to make some kind of bushing to hold the bearings solidly, and probably a real witch to get perfect alignment. Probably would need to weld in a new piece of metal, etc. But probably there is some clever minimal way to do it -- especially if you had no other choice (WWII pilot stranded needs to fix generator, etc.).
Were is there a place to get parts for motor
Plz show for us changing all wire like washing maching right and left turn one phase
I have a Dayton 3/4 hp single phase (6K376BA) that I want to change rotation on. Can you link me to a video you may have made to do that or another you would recommend? Also I need an end plate to cover the wiring access if you might know where I could get one please? Thank you for making and sharing your video!
Mac
Is the motor plate intact? If it is there is a wiring diagram on there that shows to switch 2 wires. You'll have to search online for the wiring cover. There are a few places around that stock motor parts such as centrifugal switches. They may have something.
The motor plate is intact but all the wires are numbered with no other reference. I'll check with centrifugal switches for the wiring cover. Thank You.
Good one, Smart Man
What are those bearings called, and where can you get them
Great tutorial! You lost me at the end with the wiring though. A picture would have simplified things. Thanks, it was useful.
i will never plug those 110vac caps on 220v mains even though you mentioned that is not necessarily indicating a voltage rating.
As long as the VAC rating is higher than your input voltage you're good
I am working with an old Westinghouse 110v 2 speed motor and I would like to change rotation could you help me ?
"Park the car in Harvard Yard"...lol nice vid
Thanks great lesson.
my 6" belt sander is loosing power how can I fix it?
Victor Plawski First and easiest to check is the bearings. If the shaft doesn't spin free then there's your problem. Next up would be the capacitor. Check for leaks. If it looks like crap just replace it. They're cheap. Next up is the centrifugal switch contacts. Clean them and make sure the switch functions and the springs and everything move.
I have an old, old 1/3 hp motor off an old Delta drill press. It wouldn't start on its own. I suspected the starter capacitor was bad but it checks good. Have any idea's as to what's ailing it?
If it's not the capacitor I'd have a look at the centrifugal switch. Could very well be that the switch has a lot of carbon build up from arcing and is not making good contact. Give the contacts a light sand with some emery and make sure they close.
Ronald Knipp
16:22 souds like a garbage disposal, but you could make a homemade garbage disposal
good video
Hi. I have an old 1950s 3/4 horsepower craftsmen start capacitor motor that came off a table saw. I am rebuilding it and the motor worked just fine before I took the bearings off and replaced them when I put it all back together it just humms and won’t spin also the shaft gets stiff and won’t spin but when I shut everything off the shaft will spin again. Can you tell me does this have anything to do with maybe the capacitor being bad or should I check something else?
Double check your wiring. Seems like you have something in the wrong place.
Hi, I was wondering if you could help me out with a wiring issue im having. I have a motor that is 115/230v 3/4 hp that i just bought from a salvage yard for my bench top mill and am not sure how to wire it in. It had 3 wires coming out of the back of it; black, white, and green. the green went to a ground screw so thats easy, then it was white and black so i assumed it was setup for 115 v so i wired it in that way and the motor fires up no problem. the problem is that it doesnt seem to have the power that it should and I was curious if maybe it was already setup as 230 and I have it set up as 115. if thats the case would the motor even work if i wired it to 115 and it was supposed to be 230? It has a motor plate but no schematic or anything about switching the power around. any help would be appreciated. I also noticed the part in your video also when you said the motor wasnt getting hot, mine gets warm fast when i turn it on so thats what made me start thinking i have something wrong too.
Does the nameplate say 115/230? If so, only a black and white makes no sense, because there would be no way to change the voltage setup. Getting warm fast on 115 probably means there is something wrong with the motor. If the starting switch is not opening, that would make it get hot very fast. I think you might have a dud.
larry brunetti, yes the name plate does say 115/230 and there are a few terminals inside the motor you can change the wire positions around to. There is no wiring diagram nor could I find one online. I assumed it was wired 115 so that's the way I hooked it up. I not familiar with them enough to know whether or not it would even work if it's setup for 230 and I wired it to 115. I was thinking maybe it was getting hot and doesn't have much power because it's missing the other power leg and only half the windings are being energized?
Chris, out of the motor there will be 6 wires. Two for the starting winding, and the other pair for the main windings. For 230 v operation, the main windings will be connected in series, and the staring winding will be across ONE of the staring windings. For 115 v operation, the starting windings will be in parallel, with the starting winding across BOTH of them. In both cases, the main windings must be phased, as I described in the article above. If the motor starts on 115, but is weak, it is probably wired for 230, and if it doesn’t get up to speed, the starting winding will not kick out and the motor will get hot and draw a lot of current. Either try it on 230, or rewire it according to my article. If you take all of the wires apart, you can use an ohmmeter to check the coils out. You can get an ohmmeter at NAPA, True Value Hardware or Radio Shack:
the main windings will be the same resistance
the starting winding will be different than the mains.
Phase the mains, and connected as I described. Should have no problem.
Good Luck!
hi thnx for your nice movie I am looking for a movie that shows when coils are ruined how we can distinguish and how can we repair it .....what are the scientific back ground and more ...how can you help me?
The way you connect the wire is not clear
plage sar 50 hp canaction information sam tell you.
but not work
3000th subscriber! Happy 3000nd :).
Hi Mr. H. I have an old 1947 drillpress the motor is weak, I have to hand-spin it to get it going, and on the fastest belt - it just hums.. "1/2 Horsepower Ball bearing 1750 RPM, 115 volts 60 cycle 6.7 AMP. Type CNB K8 Model 1156962. Is this something an amatuer can rebuild? I'd really like to get this running better. Thanks for any advice. ruclips.net/video/vUtktQjmJzA/видео.html
Yes relatively easy to take apart. More than likely the crease in the bearings has turned to peanutbutter. You can replace them or try to clean and regrease if they don't have seals.
Prove it......
😆