What an excellent find! I appreciate the pacing and just the right amount of information to get you going without being overwhelming. Extra props for being so active in your comments. I'm looking forward to checking out all you have to offer. Thank you, good job and keep up the good work!
So I switched on my vacuum and it began to smoke. I checked the commutator bars with the lowest resistance and in the four of the tests the resistence couldn't settle on a reading: it would spikes and even show "OL". I didn't need to test given the smoking issue but wanted to know where the problem was. Thanks for the this lesson. It was straight to the point.
Gracias por brindar tus conocimiento! estoy reparando un cepillo eléctrico makita y todas las pruebas tengo luz verde, pero aun así chispea mucho el inducido al prender la maquina, lo que noto es una decoloración en algunas delgas y no hay ninguna delga levantada para presentar esta chispa, mi conclusión es que hay algún corto interno entre las delga del inducido pero no en el cableado de las bobinas.,
..my utmost thank you to you.. I have a gbh 4-32 that has been broken for a long time and I was thinking of throwing it away but after watching this video and a few other related videos on your channel, the machine is now working.. i subscribe..
One of the Best Tutorial DIY because he was Clear, non monotone, and easy to understand,and to the point without any bull. I would like to know: if I purchase a motor followed hooked up wiring as per direction from rear ran fine for about one 1 min then slowed down , this is to a compressor that has ben running for 16 years so power to the power switch is more than fine. Help me. Ps this is the second motor in two days from harbor. Freight Smith and Jones 3hp
I was out driving my 1944 GPW ford jeep. I noticed the amp meter was not working, reading zero. I decided to head home as i became worried. The amp meter needle then moved into the negative side of the guage which indicaded the battery was been drained on energy. After a while the needle moved to show a positive charge. i thought ok, all good, jeep has fixed itself. 😅👌🏻👍🏻. As i continued along home, suddenly the amp meter went totally crazy. The needle was flicking from side to side, the higher i reved the engine, the more violently the amp meter needle flicked from side to side. 🤤😓😭😭. I made it home ok. My jeep has a 12 volt system. New external voltage regulator & battery installed 3 months ago. I didn't know what to do or where to start. I found your video , thank God. Removed the generator/stripped down. Generator internals were filthy/full of dried dirt/dust as if it was dropped in mud for 6 months, then installed in the jeep. Probably dirt from world war 2, 😅🤣. Completely cleaned the internals with contact cleaner aresol, housing/armature/commutator. Surprisingly the 2 brushes had probably 60 to 70 % left.. Cleaned commutator bars where the brushes make contact with 800 fine grit paper. Commutator bars came up like new. Filed the brush surface that contacts the commutator bars with a file, so it was flat for better surface contact with the commutator bars. Done 3 tests on the armature as per your instructions. 2 ohms & 1 continuity tests. Armature passed the tests with flying colours. I assembled generator/ installed in jeep, left the fan belt off the generator. To test the generator, i connected a wire between field terminal & armature/dynamo terminals on the generator . I then ran a 2nd wire from the positive side of the battery to the wire that connected both terminals on the generator. The negative lead must be connected to the battery. The pulley spun on it's own indicating it was working properly. Connected up wires, started jeep engine. Reved the engine to approx 700 to 900 RPM, amp meter needle moved across to the positive charge on the amp meter. Tested battery charge rate was 14.2 volts at approx 700 to 900 RPM. All the problems were caused by a gut full of dirt in the genny, 😅🤣😂 Thankyou for sharing your information, really got me out of trouble. 😂🤣😅👌🏻👍🏻👏🏻👏🏻👏🏻 Cheers from 🇦🇺
Thank you very much for the video It is a very good demonstration. 1) Could you please confirm though an easy way to measure correctly /accurately 180 degrees on the part indicated. 2) In the 2nd test are you checking comparing the 1st with 2nd (and) the 2nd with the 3rd and so on OR the 1st with the 2nd (and) the 3rd with the 4th and so on. I look forward to your reply From a Learner Thanks
Hi John, 1) for the 180 test, value itself is not important, consistency is. I usually mark on the commutator the start and 180 position and check every time I have landed on the right slot. 2) For the bar to bar test, go 1 to 2, 2 to 3, 3 to 4, etc The idea is to check if their is unbalancing across the wiring, which indicates an issue impacting the engine to properly turn. 180 test or bar to bar is simply to make sure a similar portion of the wiring is checked every time. Hope that clarifies.
Excellent video. Going step by step....again....again. Most youtube videos skip basic steps like setting multimeter before each test and you have to go back to beginning to see what is the multimeter set to . Same thing with measurements....taking two measurements after each other is perfect and enough to show roughly the same reading. Nice work, LabOtomy ! :-)
Thank you SO much for posting this video. I have an vintage sewing machine that is not starting up when I plug it in. Hopefully it's a short in the wires or wires not connected properly and not the commutator/aperture.
awesome track man. it's killin me tho. was a dj for close to 20 years (tribal house, breaks, dnb, later some dubstep -i dislike joining bandwagons when they're in full swing). anyways, I stopped paying attention to the video itself and am now lost in good feelings and love of times past. thank you :) ..oh yeah, I'll make sure to watch the video again to learn some electronics :) -Art (djseek/ASF, Santa Cruz, CA)
To perform this test properly, a four lead, low ohms meter is required at minimum, and much better to use a growler. To properly test for grounds between the windings and the Core, a megger is really required, or at very least set your meter to the Highest ohms setting, Not the lowest. The insulation test need only be performed between ONE commutator bar and the armature Core, because All commutator bars are connected together!
"The insulation test need only be performed between ONE commutator bar and the armature Core, because All commutator bars are connected together!" yeah thats the right way.i think he has no idea what is happening
Good video. Mostly when i see the Armature of an electric motor ? Is when my Angle Grinder stops working. IF the bushes are worn replace them. If Not worn, and the commutator is worn. Then in the bin it goes and off to buy a New Angle Grinder, LOL.
I used your instructional video to clean and test my armature. Can you tell me the easiest way to clean the shavings from inside that are attached to the magnet? Thank you.
If you measure no bar to stack leakage on the first bar, shouldn't that conclude the test? Any leakage from the windings to the stack would show up on all of the bars.
@@TheLabOtomy hello sir As i tested same u told in video We have 180v dc motor rpm is 1000.....rpm is flacuating around 300+or-.when rpm is 1000 1. Cleaned the comutator. 2.fixed new carbon brush 3.at starting rmp is constant after when carbon brushes are slightly corved inside starts flactuating Thank u
You can Definately rewind the wires and use it again. The main problem isn't burnt wires, but the alloy, assembly itself, if it's still in good shape. Electric motors usually have an air cooling fan to them. Sometimes a heat sink or heat resistant shroud , thicker wires can pro long their use. How they short outs, perhaps small metal debris,melted resin, from heavy use .
I have this exact looking motor on a drill press. When I power it on it hums a little at 0 speed but if I try to increase the speed it shuts my whole press off due to some kind of over temp protection.
I have several broken motors, and I find this video instructional because at least I can tell for certain that the motor is irreparable, (something that I already well figured out, as the vacuum cleaner does not clean and the hair dryer does not move air). The video is very well done (artistic, indeed), and I've been hoping it could give me a hint on how to fix the coils by the bottom stack, but I don't think this is feasible with my limited capacities. Like an egg and myself, my coils and brain are fried, it seems... Nevertheless, the little funnies help me shed off the tears of what is now just a lump of metal... Next, LabOtomy, sir, would you kindly show us how to actually *fix* the f'in thing? Much appreciated, D.P.
Difficult to assess without knowing the specifics, but a motor traditionally overheats because it pulls many amps, this due because it has to work hard. This could be due to the operations being conducted (i.e. mowing high grass), or due to mechanical restrictions (worn off bearings, or stuff stuck in the blade). Hope it helps
Congratulaciones, sólo hablo español. Espero me puedan entender; a pesar de todo pude entender algunas cosas. Eso quiere decir que es muy explícito. De nuevo gracias
Best video on this topic. And a nice disclaimer. My field is black and has almost no insulation left. The armature has one suspicious coil. All of them are 0.3 to 0.5 but one is 0.6 , could it be normal or could this even be the reason why the field overheated? I dont know nothing obout the provious use of the mashine. It's a 15yr old dewalt but the blade was pretty dull.
So, a possible scenario in your case could have been: 1) Blade is dull, which causes 2) Motor to have to work harder, which causes 3) Motor to pull more amps, which causes 4) Armature coil to heat up beyond normal, which causes 5) Damage to the internal wiring (resulting in resistance discrepancy within the machine coils, 0.3 to 0.6 is a 100% variation which is real source of concern) and degradation to the insulation material (burning through and truning black) 6) Which causes the motor perceiving a loss of power to go back to 3) for a ultimate catastrophic failure The Cause and effect theory at its best!
@@TheLabOtomy I could not have explained that better. Got an old dremel here that's got the same variance. I just happen to have some rolls of magnet wire that's just a little thicker than what's on it now. Time to rewind the armature and field core. Why would I do this? Because I can!! And just a little payback for pissing me off and failing when I needed it most! And from what I understand this particular model is known for this failure, and I am surprised that with this being a flex shaft only model they would have used a better quality wire and cooling fan! In any case, Thank you for this informative video👊
May i add, your 3rd Test should also been done on Meg Ohm scale, reading should be higher than 1 megohm. Don't touch the probe ends as you will false readings
Is this available for cordless tools? today i replaced brushes on my 18 v, dga 452 makita angle cordless grinder, checked the armature (no short circuits), but after reassembling it doesn't run smooth or constant as new, after a few seconds the speed varies for a short period and it comes back again, but has enough power to cut someting. I noticed a little bit of play on the big bearing. What do you think? What should I do? Thanks in advance.
@@TheLabOtomy yes, I even clean with a fine sandpaper the copper contacts and replace the holder with a new one. I will replace soon as posible the 2 armature bearings with 2 new skf.
ua-cam.com/video/b9XxlYusuR8/v-deo.html this is the grinder, I made a video today, it looses rpm in minute 0:25 and returns back for 30 sec, but still oscillate. Never ever dealed with this kind of problem and repaired a lot of my grinders.
@@TheLabOtomy I do care about my tools. I work with 20 power tools and 10 inverters/welders and I can't afford to throw them away and buy new ones. I repair what I can by myself or at a specialized shop and save a lot of money with a little bit of struggle 🤝🥂
General question a starter motor I'm troubleshooting has four brushes each separated by 90 degrees. The brushes as 12 o'clock and 6 o'clock are positive and brushes at 3 o'clock and 9 o'clock are negative. If the armature windings terminate at commutator segments that are 180 degrees apart. How is there current flow? It seems like both ends of the armature windings would be at the same polarity at any given moment. What am I missing?
You can run this type of motor on a very low d.c. voltage to test it. A vacuum cleaner motor wil run on 9 to 12 volt d.c.! The rpm is of course not high than. Be careful and do not connect it to a car battery. Dangerous when short circuit! Vacuum cleaner motors without electronics in it to change the power of the suction, you can supply direct on 9 volts to get it run. Try it yourself.
thank you! using this test procedure now on a used motor i just bought.. do you know the difference in using a growler rather than this? does the growler induce more voltage to make shorts more noticeable? it seems as though this should work about as well.
The growler is a specialized device, so will be faster helping validating the quality of an armature insulation for eventual shorts... this said, being specialized, means it is less common than a standard multi-meter in a work-space... with the multi-meter, I also like to confirm the balancing of the coils, not sure if the growler can deliver on that (leaving the last open for any growler specialist to infirm/confirm on that statement)
thanks again! I ask because I have a motor I need to repair for my race car that is a bit hard to find, one of the people I called for help said a regular multimeter couldn't do the same job even good enough for me in my garage, considering this video and the fact that the part is mine, im going to test it this way and see how that works.
As mentioned in my other answer to your questions, there is no 1 answer as all motors are different (in number of winding loops, winding design & patterns, motor sizes, winding wire gauges etc). If you really need a value, those should be found in the product specs (if available)
Straight to the problem, no bullshitting, watching the video solves all your problems. Thanks! ❤
Thanks for the feedback
What an excellent find! I appreciate the pacing and just the right amount of information to get you going without being overwhelming. Extra props for being so active in your comments. I'm looking forward to checking out all you have to offer. Thank you, good job and keep up the good work!
Thanks for the kind words, hope you will find something of interest in the channel
Best presentation of this kind I've seen on YT. Congrats! :)
Thanks for the positivity!
So I switched on my vacuum and it began to smoke. I checked the commutator bars with the lowest resistance and in the four of the tests the resistence couldn't settle on a reading: it would spikes and even show "OL". I didn't need to test given the smoking issue but wanted to know where the problem was. Thanks for the this lesson. It was straight to the point.
Yep, you found your fault!
Gracias por brindar tus conocimiento!
estoy reparando un cepillo eléctrico makita y todas las pruebas tengo luz verde, pero aun así chispea mucho el inducido al prender la maquina, lo que noto es una decoloración en algunas delgas y no hay ninguna delga levantada para presentar esta chispa, mi conclusión es que hay algún corto interno entre las delga del inducido pero no en el cableado de las bobinas.,
very informative video and very good edited. Thank you
Thanks
excellent video
Glad you liked it!
..my utmost thank you to you.. I have a gbh 4-32 that has been broken for a long time and I was thinking of throwing it away but after watching this video and a few other related videos on your channel, the machine is now working.. i subscribe..
Nice Angelnoheart, always good to hear about people fixing their stuff!
One of the Best Tutorial DIY because he was Clear, non monotone, and easy to understand,and to the point without any bull.
I would like to know: if I purchase a motor followed hooked up wiring as per direction from rear ran fine for about one 1 min then slowed down , this is to a compressor that has ben running for 16 years so power to the power switch is more than fine. Help me. Ps this is the second motor in two days from harbor. Freight Smith and Jones 3hp
I was out driving my 1944 GPW ford jeep. I noticed the amp meter was not working, reading zero. I decided to head home as i became worried. The amp meter needle then moved into the negative side of the guage which indicaded the battery was been drained on energy. After a while the needle moved to show a positive charge. i thought ok, all good, jeep has fixed itself. 😅👌🏻👍🏻. As i continued along home, suddenly the amp meter went totally crazy. The needle was flicking from side to side, the higher i reved the engine, the more violently the amp meter needle flicked from side to side. 🤤😓😭😭. I made it home ok. My jeep has a 12 volt system. New external voltage regulator & battery installed 3 months ago. I didn't know what to do or where to start. I found your video , thank God. Removed the generator/stripped down. Generator internals were filthy/full of dried dirt/dust as if it was dropped in mud for 6 months, then installed in the jeep. Probably dirt from world war 2, 😅🤣. Completely cleaned the internals with contact cleaner aresol, housing/armature/commutator. Surprisingly the 2 brushes had probably 60 to 70 % left.. Cleaned commutator bars where the brushes make contact with 800 fine grit paper. Commutator bars came up like new. Filed the brush surface that contacts the commutator bars with a file, so it was flat for better surface contact with the commutator bars. Done 3 tests on the armature as per your instructions. 2 ohms & 1 continuity tests. Armature passed the tests with flying colours. I assembled generator/ installed in jeep, left the fan belt off the generator. To test the generator, i connected a wire between field terminal & armature/dynamo terminals on the generator . I then ran a 2nd wire from the positive side of the battery to the wire that connected both terminals on the generator. The negative lead must be connected to the battery. The pulley spun on it's own indicating it was working properly. Connected up wires, started jeep engine. Reved the engine to approx 700 to 900 RPM, amp meter needle moved across to the positive charge on the amp meter. Tested battery charge rate was 14.2 volts at approx 700 to 900 RPM. All the problems were caused by a gut full of dirt in the genny, 😅🤣😂 Thankyou for sharing your information, really got me out of trouble. 😂🤣😅👌🏻👍🏻👏🏻👏🏻👏🏻 Cheers from 🇦🇺
Thanks for sharing. happy to read it has been helpful
Great video I have a bunch of Tecumseh Snow King starters to check.
Good luck
Very easy and convenient. Thanks
Thanks for the feedback Zaheer
Thank you very much for the video It is a very good demonstration.
1) Could you please confirm though an easy way to measure correctly /accurately 180 degrees on the part indicated.
2) In the 2nd test are you checking comparing the 1st with 2nd (and) the 2nd with the 3rd and so on OR the 1st with the 2nd (and) the 3rd with the 4th and so on.
I look forward to your reply
From a Learner
Thanks
Hi John,
1) for the 180 test, value itself is not important, consistency is. I usually mark on the commutator the start and 180 position and check every time I have landed on the right slot.
2) For the bar to bar test, go 1 to 2, 2 to 3, 3 to 4, etc
The idea is to check if their is unbalancing across the wiring, which indicates an issue impacting the engine to properly turn. 180 test or bar to bar is simply to make sure a similar portion of the wiring is checked every time. Hope that clarifies.
Excellent video. Going step by step....again....again.
Most youtube videos skip basic steps like setting multimeter before each test and you have to go back to beginning to see what is the multimeter set to
. Same thing with measurements....taking two measurements after each other is perfect and enough to show roughly the same reading. Nice work, LabOtomy
! :-)
Thanks for the feedback Peter X, appreciated
gracias por el tiempo que le dedico a hacer el video, muy útil la información.
Sangat membantu , terimakasih infonya
Thank you SO much for posting this video. I have an vintage sewing machine that is not starting up when I plug it in. Hopefully it's a short in the wires or wires not connected properly and not the commutator/aperture.
It's got a plug ? That's not vintage. Vintage is the Old treadle operated Singer machine my Mother used to rattle away on when we were kids. . . .
I appreciate your video very much. Thanks.
Thanks MrKromy67
That was very helpful. Thank you!
Welcome
Excellent tutorial I have learned something new today - always a good day!
Thanks for the feedback
THANKS FOR YOUR SHARING SIR
Most welcome
Nice video good demonstration to test
Thanks Tyrone
very well explained ... bravo ! ;)
Thanks Yves
THANK YOU!
Welcome
Thank you so much for your video, helps maintenance students a lot
Happy to help
Nice info, thanks
Wow great vid all the info you need
Good to hear, thanks
Very practical and helpful....thank you
An important lesson, Thank you.
it helps me identifying drill motor issue
Nice
The format, the graphics, the contents and even the music is very clear and amusing, great !
Thanks for the feedback
Thanks>>>>Subscribed!!!
Thx for this video!
Welcome
its a good video, thank you
Thanks Joseph
awesome track man. it's killin me tho. was a dj for close to 20 years (tribal house, breaks, dnb, later some dubstep -i dislike joining bandwagons when they're in full swing). anyways, I stopped paying attention to the video itself and am now lost in good feelings and love of times past. thank you :) ..oh yeah, I'll make sure to watch the video again to learn some electronics :) -Art (djseek/ASF, Santa Cruz, CA)
Good to hear (WARNING / WARNING / This pun was intended... \ WARNING \ WARNING)!
Perfect 👌👍Thank you 🙏🌹
👍🌹
easy to follow video, great work!
Glad you liked it!
To perform this test properly, a four lead, low ohms meter is required at minimum, and much better to use a growler. To properly test for grounds between the windings and the Core, a megger is really required, or at very least set your meter to the Highest ohms setting, Not the lowest. The insulation test need only be performed between ONE commutator bar and the armature Core, because All commutator bars are connected together!
sounds good. Please make a video for us with more explanation!
"The insulation test need only be performed between ONE commutator bar and the armature Core, because All commutator bars are connected together!" yeah thats the right way.i think he has no idea what is happening
to debil, nie ma mu co tłumaczyć, i tak nie zrozumie
Good video.
Mostly when i see the Armature of an electric motor ?
Is when my Angle Grinder stops working.
IF the bushes are worn replace them.
If Not worn, and the commutator is worn.
Then in the bin it goes and off to buy a New Angle Grinder, LOL.
Thanks so much for your video !
It saved my day !
Best regards,
Good to read, thanks for the feedback
I used your instructional video to clean and test my armature. Can you tell me the easiest way to clean the shavings from inside that are attached to the magnet? Thank you.
Gently brush them off
Good job
Thanks
Great explanation, clear and concise! Thanks!
nice video
Wonderful lesson about Broken Electric Motor? HOW TO Test If A Motor Armature With Commutator Is Damaged
good clip
Thanks
Thanks Master
Welcome
very good
Thanks
To test continuity to ground wrap a braided copper wire around the comm then measure from braid to stack ( ground) it is much faster.
Indeed!
if any of them are shorted to ground it will show in any of them, the resistence may be lower but any value other than open is bad
Excellent
Thanks
Nice discription below the video tq
Thanks
Nice!!!
Thx
Useful video
If you measure no bar to stack leakage on the first bar, shouldn't that conclude the test? Any leakage from the windings to the stack would show up on all of the bars.
Good work
good video
Thanks man
Very good
Thx
Very clear and simple explanation. Thank you definitely helpfull.
Great to hear!
@@TheLabOtomy hello sir
As i tested same u told in video
We have 180v dc motor rpm is 1000.....rpm is flacuating around 300+or-.when rpm is 1000
1. Cleaned the comutator.
2.fixed new carbon brush
3.at starting rmp is constant after when carbon brushes are slightly corved inside starts flactuating
Thank u
handy video
excelente mi pana...good dato
Dzięki za info
great test bravoooo
You can Definately rewind the wires and use it again. The main problem isn't burnt wires, but the alloy, assembly itself, if it's still in good shape. Electric motors usually have an air cooling fan to them. Sometimes a heat sink or heat resistant shroud , thicker wires can pro long their use. How they short outs, perhaps small metal debris,melted resin, from heavy use .
nice...grate test, tank you
Wilcom
Great tutorial, easy to learn..... thanks.
Welcome! Thanks for the feedback
very useful thanks
I have this exact looking motor on a drill press. When I power it on it hums a little at 0 speed but if I try to increase the speed it shuts my whole press off due to some kind of over temp protection.
Dziękuję bardzo, skorzystałem!!!
Great video
Thanks!
I have several broken motors, and I find this video instructional because at least I can tell for certain that the motor is irreparable, (something that I already well figured out, as the vacuum cleaner does not clean and the hair dryer does not move air).
The video is very well done (artistic, indeed), and I've been hoping it could give me a hint on how to fix the coils by the bottom stack, but I don't think this is feasible with my limited capacities.
Like an egg and myself, my coils and brain are fried, it seems...
Nevertheless, the little funnies help me shed off the tears of what is now just a lump of metal...
Next, LabOtomy, sir, would you kindly show us how to actually *fix* the f'in thing?
Much appreciated,
D.P.
Thanks for the input, will think about it
At least a comment as to is it worth repairing. For most it isn't but some of us like that challenge. Why not....
@@ericsnyder3689 Excellent attitude!
good video. thank you
Welcome
what causes overheating of starter on lawn mower., i have glued the magnets back not sure if they have to be in a certain way, mine had 2 magnets .
Difficult to assess without knowing the specifics, but a motor traditionally overheats because it pulls many amps, this due because it has to work hard. This could be due to the operations being conducted (i.e. mowing high grass), or due to mechanical restrictions (worn off bearings, or stuff stuck in the blade). Hope it helps
Great video, nice clear instructions👍👌👍👌
Thanks
Good job 😁
Congratulaciones, sólo hablo español.
Espero me puedan entender; a pesar de todo pude entender algunas cosas. Eso quiere decir que es muy explícito.
De nuevo gracias
Best video on this topic. And a nice disclaimer. My field is black and has almost no insulation left. The armature has one suspicious coil. All of them are 0.3 to 0.5 but one is 0.6 , could it be normal or could this even be the reason why the field overheated? I dont know nothing obout the provious use of the mashine. It's a 15yr old dewalt but the blade was pretty dull.
So, a possible scenario in your case could have been:
1) Blade is dull, which causes
2) Motor to have to work harder, which causes
3) Motor to pull more amps, which causes
4) Armature coil to heat up beyond normal, which causes
5) Damage to the internal wiring (resulting in resistance discrepancy within the machine coils, 0.3 to 0.6 is a 100% variation which is real source of concern) and degradation to the insulation material (burning through and truning black)
6) Which causes the motor perceiving a loss of power to go back to 3) for a ultimate catastrophic failure
The Cause and effect theory at its best!
@@TheLabOtomy I could not have explained that better. Got an old dremel here that's got the same variance. I just happen to have some rolls of magnet wire that's just a little thicker than what's on it now. Time to rewind the armature and field core. Why would I do this? Because I can!! And just a little payback for pissing me off and failing when I needed it most! And from what I understand this particular model is known for this failure, and I am surprised that with this being a flex shaft only model they would have used a better quality wire and cooling fan!
In any case, Thank you for this informative video👊
That's a quality tutorial
Excellent explanation....congratulation!
Thanks Domenico
Great👍👍👍👍👍
May i add, your 3rd Test should also been done on Meg Ohm scale, reading should be higher than 1 megohm. Don't touch the probe ends as you will false readings
Is this available for cordless tools? today i replaced brushes on my 18 v, dga 452 makita angle cordless grinder, checked the armature (no short circuits), but after reassembling it doesn't run smooth or constant as new, after a few seconds the speed varies for a short period and it comes back again, but has enough power to cut someting. I noticed a little bit of play on the big bearing. What do you think? What should I do? Thanks in advance.
Are the brushes properly / securely seating and making good contact with the commutator?
@@TheLabOtomy yes, I even clean with a fine sandpaper the copper contacts and replace the holder with a new one. I will replace soon as posible the 2 armature bearings with 2 new skf.
ua-cam.com/video/b9XxlYusuR8/v-deo.html this is the grinder, I made a video today, it looses rpm in minute 0:25 and returns back for 30 sec, but still oscillate. Never ever dealed with this kind of problem and repaired a lot of my grinders.
@@calinsandor9518 Good to see there are still people taking good care of their stuff! Repair Reuse Recycle!
@@TheLabOtomy I do care about my tools. I work with 20 power tools and 10 inverters/welders and I can't afford to throw them away and buy new ones. I repair what I can by myself or at a specialized shop and save a lot of money with a little bit of struggle 🤝🥂
Hi great video, how much variance in resistance is acceptable?
Plot the data and see if there are odd spike values or if the chart looks homogeneous
@@TheLabOtomy podrías indicarme como realizas la grafica? Gracias por tu ayuda!!
Muy bien
Gracias
General question a starter motor I'm troubleshooting has four brushes each separated by 90 degrees. The brushes as 12 o'clock and 6 o'clock are positive and brushes at 3 o'clock and 9 o'clock are negative. If the armature windings terminate at commutator segments that are 180 degrees apart. How is there current flow? It seems like both ends of the armature windings would be at the same polarity at any given moment. What am I missing?
Commutator segments are not, per se, connected on a 180 degrees direction. It all depends on the motor so can have many different configurations.
Thanks Nice channel
You can run this type of motor on a very low d.c. voltage to test it. A vacuum cleaner motor wil run on 9 to 12 volt d.c.! The rpm is of course not high than. Be careful and do not connect it to a car battery. Dangerous when short circuit! Vacuum cleaner motors without electronics in it to change the power of the suction, you can supply direct on 9 volts to get it run. Try it yourself.
I got resistance spike in bar to bar, can it be fix?
Thank you.
Thank you too, you are fabulous
احسنت فحص مضبووط..thanks
Super 💓
Thanks
thank you! using this test procedure now on a used motor i just bought.. do you know the difference in using a growler rather than this? does the growler induce more voltage to make shorts more noticeable? it seems as though this should work about as well.
The growler is a specialized device, so will be faster helping validating the quality of an armature insulation for eventual shorts... this said, being specialized, means it is less common than a standard multi-meter in a work-space... with the multi-meter, I also like to confirm the balancing of the coils, not sure if the growler can deliver on that (leaving the last open for any growler specialist to infirm/confirm on that statement)
thanks again! I ask because I have a motor I need to repair for my race car that is a bit hard to find, one of the people I called for help said a regular multimeter couldn't do the same job even good enough for me in my garage, considering this video and the fact that the part is mine, im going to test it this way and see how that works.
A grower is the best way
Nice,
I just made a video how to repair rusty angle grinder with broken with explanation because i read the comments of this video.
Thanks.
Rất chuyên nghiệp, cảm ơn bạn
Hola Saludos me yamo Lázaro reparo esas herramientas es bueno estos vídeos.
What should the resistance be after deducting the lead resistance?
As mentioned in my other answer to your questions, there is no 1 answer as all motors are different (in number of winding loops, winding design & patterns, motor sizes, winding wire gauges etc).
If you really need a value, those should be found in the product specs (if available)
Informative
Bit usually when it's shorted or wire broken it can be seen easily
Hm... if the heat causes the insulation to melt on the inside of the coil, could be hard to visually detect
No teste de isolamento da massa, deveria ter colocado na escala de 2000k
hola amigo, podrías indicar por que se debe realizar de esta forma? Gracias!
Before you bin it though. Try scraping out the slots between commutator segments with a piece of sharp metal that fits the gap.
Thanks mark for the tip. What would you do the with the mica you extract?
So when I would did the bar to bar it went down from 1.4 to 1.3. not a big difference but it still changed. Does that indicate a problem?
no amigo, por ejemplo una diferencia entre una lectura y la otra podría ser 1.4 a 3.5, o valores que están mu separados, ya seria preocupante.
useful video like