You really made it hard for yourself bringing the Stator out: Push Stator through - when it’s almost out you can lift the rotor up by hand, bringing it all the way to the top of your Press. Now you can loosen the press again and take the rotor away - now you can bring the rotor down and take it away. What’s screeching is the unsupported rotors magnets connecting with the Stator at one point. Totally normal. Even though very very nice work - those were just my two cents! I was really enjoying your video! :)
So I had an old e-bike hub motor that was causing issues cutting out, so I took it apart it was very rusty so I give it a good clean and also renewed the soldering joints of the hall senses, my question is I saw somewhere on eBay some guy selling some sort of silicone fluid that's supposed to help transfer the heat from the coil to the permanent magnet aluminum body of the wheel is this needed? I'm thinking to just use lithium grease
Very interesting. I need to replace the hub wiring pony tail, mine got stretched and no longer sends power to the hub. Is there a network of professions that do this kind of work in the Indianapolis area? I don't feel qualified, but every bike shop just wants to replace the hub in its entirety.
Thanks! I don't own an ebike but my brother does and I get tasked with maintenance and repairs... nice to know what all is involved long before it's ever necessary. Will definitely check out your other vids!
I do my cycle repairs myself and don't have many essential tools and I often say that if only I had a third arm things would be so much simpler. Glad to know I wasn't alone
You're pretty honest up until the end and I commend you for that and I want to say thank you... but when you were putting it back together. you were pushing the stator out. When you were putting the first cover on. you didn't really explain how you got the stator to go back in when put the others cover on or really even how you got the stator back in in the first place. You just kind of said it was a pain. And please call the stator a stator not a stader. Driving me nuts calling it a stader. Oh and FYI if you ever have to take a hammer to something that is a stud or has threads. put the nut on it until the nut is almost flush. then use a block of wood or brass and you'll be good to go. you can beat on it pretty hard without messing up the threads. I'm an automotive tech and just wanting to learn about electric motors. Thanks for the video greatly appreciated.
Will the motor spin if I don't have the side cover bolts in? Because I had to replace the hall sensors for a friend and everything went well, Now I'm going to power everything up and see if the error code is gone and the motor spins. But he never gave me any bolts for the side covers, I'm not sure if they need to be screwed in place to hold something so the inside can spin, or if it will be ok to test for movement without them. Then he can install the bolts when I return it to him. Thanks
Hi man.. i'm from Verona Italy.. thanks for your nice video i would like to understand more about hub motors. Basicly the rotor Is made by magnet and Is It arranged external for stator?
Thank you for the video I was wondering about this as my drop out is 170mm and I’m trying to switch out my frame to a frame with a 155mm drop out. If you don’t mind me asking where do you get the replacement shaft?
21:44 I would have liked to see you put the magnetic stator together with the casing... I imagine it's pretty violent the way it comes together? Kinda dangerous "keep fingers clear!" kinda thing? ...........actually........come to think of it......... why did you separate them in the first place? you don't need to in order to get the axle out, right?
I was ready to film it, but there were only two of us in the shop for this task which required both of us. Next time I do it, I will film and post the event.
How do you go about rejoining the stator/cover. I saw another videos where they line it up and let it snap shut. Looked like you could easily damaged the magnets?
when assembling the bearing in thr motor cover, the sleeve should be small so that it rests on the bearing's inner diameter. The way you are doing it, the pressing force is transmitted through the ball bearing which damages it. Moreover, while doing this operation, the whole motor should rest on its axle and not on the 4 small columns. the way you are doing it, the forces are trabsmitted to the driving axle through the ball of the rear ball bearing... You want the forces to be transmitted directly from the inner ring of the upper ball bearing to the driving shaft. It is not all at the right way to assemble a bearing. That is why you feel the "spring" forces due to the cover deflection which should not be involved at all in this operation.
I was waiting for one of those sockets to go flying at about mach 9 and take out some teeth.😬 Not only that it looked as if the windings were being pushed out and distorted. 😬😬
Hi, I bought a brand new xiaomi himo z20 ebike and it's just 25km since brand new. I recently hear whining noise when the bike is under 15 kmh and the noise disappear when the speed is above 15 kmh. Would you have any idea what I should check in my case? Thanks so much.
If you testing the hail sensors you put your ground wire from multi meter on the sensor ground. You put the red lead on the blue green green or yellow wires and turn the wheel by hand. You should get a voltage reading. Repeat the process for each wire then again for all sensors. If any show no reading at all then you have a faulty hail sensor
I have a Bafang 750 watt/48 volt Brushless, Geared Hub Motor with a 190 drop out axle where the motor cable comes out through the axle. I also need to change the axle because of damaged threads, Would the process be almost the same? I realize there are planetary gears inside to change. Do you know where I can obtain a replacement axle? Thank you.
Why use silicon as a gasket? Why not simply waterproof the motor with red insulating varnish? If humidity is caught inside the motor (e.g. heat buildup will suck in water as it is not completely sealed) it needs to exit ... I have seen many a motor with drilled drain holes. Nice video.
Actually, it's not a Woodruff Key, which looks to all like a slice off of a coin. The key used (although loose-isa) can be made a bit more secure by running a series of dot punch marks on both sides and being tapped home.A slight chamfer on the starting side would also help.Or you can shim it with S.S. shim cut to pack out the key
thanks! for future reference, there called Woodruff (or half-moon) keys, used a lot in hydraulic motors, and hub assemblies, advantage of the Woodruff key is the elimination of milling near shaft shoulders. An additional advantage is a stuck key can be removed from a shaft with a hammer blow (not prying out), the circular profile will push the key out of the slot, as opposed to a standard key which will need to be pushed axially. If you've ever used a self feeding wood chipper, you kept a few in your pocket ;-)
Reading these comments it appears most everyone is a complete know it all with recommendations on how to do everything the right way. Pulling hub motors apart is a pain,and the cromotor is the beast of all beasts. Good job but for the love of God it's called a stator.
A new axle can be made at any local machine shop if they have something to copy. Stator Removal can be done with any $20 gear puller from Harbor Freight. As for pushing out the axle and pushing in an axle, perhaps a vehicle jack would work but it may be hard to build a suitable holder, but the machine shop would have a hydraulic press for sure. I am just wondering what the cost would be for a new axle, push out old, push in new. I'd want a larger route for phase wires.
Then you gotta worry about the cover plate bearings. I just did bearings on mine and it was easy. So maybe the machine shop could easily cut out a larger hole on cover plates, add larger bearings.
What gauge of motor (i.e. phase) wires do you have now? What is the diameter of the copper? Are you wanting to draw a great deal of current? If so, how much current at what voltage?
The machine shops around here (Bay Area, CA) always ask for a drawing because it is all CNC work. When I have not had a drawing, I hired them to make one. They would have me approve the drawing (via email) before machining the parts.
@@industrialebikes4956 After you press out the axle, would it be possible to push in a bushing with a torque arm (something like a bushing with a flange that could be bolted to the frame) to convert it for through-axle use? Unfortunately I haven't seen any detailed plans of the motor dimensions to see if this would be possible before ordering a chicom motor to modify. I have access to a metal ship with a press, lathe, mill etc. to make the bushing part.
The Ball I can’t imagine that there is any room for a torque arm (base mounted) in the motor. If you figure out a way, I would be interested to see what it is.
Hi, thanks for sharing your experiences. I need to replace my cromotor bearings. What are the best replacements for off road use? Would you know the size/model/manufacturer of best bearings to get? Thanks Andrew
The answer is "6204-2RS". I have UKS brand now, but any quality brand will do. SKF is the highest quality. In any case, 6204-2RS bearings will fit perfectly. I apply up to 3000 psi of pressure on the hydraulic press.
Industrial Ebikes ,, thanks again for making the effort to reply. You've been really helpful. Great detailed video, its encouraged me to crack open my cro for the first time. Happy New Year!
Hi have you ever had the up motor casing break I've had my in less than 12 months and it's making a vibrating sound and the case it looks broke all round
Thanks for posting this, I am new to Ebike converstions. My first build had a catastrophic failure last night, the hub sheared around the axle causing the wheel to lock up. I shot a little video trying to show how it failed, but it's behind the gear cassette and hard to see. I would like to upgrade to a heavy duty hub that can handle my 300+ lbs. Do you sell or repair hub drives?
I HAVE THE SAME EXACT FAILURE!! However for me it was not because 300+ lbs but instead because I heavily abused it riding down rocky mountains at high speed ...
im confused on how the stator and cover works. So when you apply throttle, does the cover start spinning around the stator? Does the cover just hover around the stator because the magnetic field keeps it from hitting the stator? How does the hub motor rotate?
The motor cover (not to be confused with the side covers) has magnets glued on the inside of it. Also, the outside of the stator has magnets glued to it. Under power, the outer magnet (assembly) rotates around the fixed inner (stator) magnet (assembly). As it happens, the side covers are bolted to the motor cover. As such, the side covers rotate with the the motor cover. This is why each side cover has a bearing inside it. Interestingly, the bearing on the drive side is pressed into the freewheel flange. The freewheel flange is bolted to the side cover. Think of it like this: the axle is bolted into the dropouts, so the axle is not going to rotate. The axle is pressed into the stator, so the stator is not going to rotate either. The motor cover and side covers will rotate, however. This is fortunate because the rim is affixed to the side covers via spoke tension. The outer magnet spins around the fixed inner magnet.
Industrial Ebikes ohh ok i understand how it spins now. But what keeps the motor cover magnets from hitting the stator magnets. There's some bearing preventing it from hitting each other? Or is the magnetic field strong enough to keep the motor cover from hitting the stator
The motor cover magnets do not hit the stator magnets because there is empty space in between the inner and outer magnets engineered into the design. The motor cover magnets are glued to the motor cover. The motor cover is bolted to the side covers. The side covers extend outside the physical reach of the inner magnets, and the side covers are anchored to the bearings on either side.
Industrial Ebikes lets say you have a ball and a ring is surrounding the ball, kind of like the planets in our solar system. The ball is the stator and the ring is the motor cover. But if you push the ring, it'll hit the ball. The thing pushing on the ring is actually the bike tire connected to the spokes connected to the motor cover. So what prevents this outer ring from hitting the ball.
When you assemble any two parts with silicone or any form-a-gasket material...apply a very thin film of grease with your finger to one of the parts and silicone to the other part...so the next time you won't damage mating faces by banging a screw driver in between...
It probably wouldn't have helped in this case but next time you need to pound on something with threads on it, spin the nut on it and hit the nut not the threaded shaft itself mushrooming the end and damaging the threads. interesting vid tho, thanx!
In tradition, the force is transmitted to the freewheel in cassette from pedaling and drive the rear wheel. But in e-bike, the source of power is the motor isn't it? So how will the freewheel work in this case?
David Kk The axle is pressed into the stator. Being rigidly bolted to the frame, the stator remains in that position at all times. The outer magnet spins around the stator. The motor cover, side covers and rim are rigidly attached to the outer magnet. The motor power causes this outer magnet to rotate.
The bearings lie between the axle and the side cover. This allows the wheel to roll freely in either direction if the motor is not under power. If the motor is under power, the bearings allow the wheel to rotate under power.
I would start with a remove and replace. If you replace it with the exact same motor, your nonoperational motor will be a source of spare parts even if you can’t fix it. The first thing that I always check is the connections in the wiring. Beyond that, you could look at removing and replacing the Hall sensors. Best thing about remove and replace is that you get back on the road faster. These motors are not expensive. You can get into the nonoperational motor at your leisure. And like I said, those spare parts will likely be a gold mine down the road.
There were two guys in the shop that day. Both of us had our hands full when we put the stator back in the outer magnet, so nobody was available to film it. My buddy held one part, I held the other part, and we kept our fingers out of the way and slowly got closer to each other until POW! The two magnets mated.
You could make a tool specifically for the job, and that may work better because the OTC 1038 gear puller used in the video has very fat teeth on the jaws. The fat teeth require the user to pry open the motor side cover at least 10mm in order to get the bearing puller in place. Make sure to pry up the side cover evenly; using two people working 180 degrees apart from one another works well. Personally, I use the (smaller) OTC 1023 for the exposed bearing and the (quite large) OTC 1038 for the side cover. These cost $41 and $62 respectively and they will last you a lifetime. As far as seating the bearings, a benchtop hydraulic press can be purchased for as low as $75. It is crucial to seat the bearings completely; I can accomplish this using less than 1500 lbs. of hydraulic pressure. I rebuild these motors a lot, and it is aggravating enough using the job specific tools listed above. It takes a fair amount of time in order to get the large bearing puller on the side cover, but once it is on it is smooth sailing. I usually slap in a fresh bearing because a 6204-2RS bearing only costs about $3.50.
By the way, I saw a video of some guys working on a hub drive in china...they beat the whole assembly on the ground to get the side cover off!!! haha! I think your way is much better.
😋I took my 1000w hub motor apart with a 9$ puller and used the force of the magnets to seat the bearing and replace the housing.Risky loosing a finger is very easy must be so careful⚡that was 3 years ago to repair i must do it again😕
Yo...you didn't need to take the rotor (magnet side) off to press out/in the shaft. That was a needless risk, especially the way you wedged the plastic in against the stator coils. Farther on, you're trying to press the bearing/flange on and there's nothing but the magnets holding the stator in...you can see it pressing out through the bottom. You're also pressing on the wrong part of the bearing; in this case you should be pressing on the inner race, against the shaft, while the shaft is locked in place. You're damaging the bearing and it's going to wear out a lot faster. In the next scene, you can see the stator sticking out quarter of an inch because the bearing hasn't been seated fully. Then you go an press on the other side in much the same way, and even result to using the screws to try and suck it in the last few millimetres. That's one reason you had such a hard time screwing it down. The bearings still aren't seated fully, you've just made the casing bulge out. Some good info here, but some bad techniques. Anyone doing this, leave the rotor on & press the bearings on properly. Go watch some videos about pressing on car wheel bearings if you need to know where to apply pressure...don't force the pressure through the bearings themselves; you'll wreck it.
Hi, is there any chance that the axle could be loose in the stator? I mean not playing loose, but I have knock when I push throttle after breaking with regen. The same knock I feel when I breake with regen after acceleration. I do not have rear brake caliper at all. I have proper, precisely fited torque arms both sides and nuts on axle are very strong tighten. Is the axle assembled same way in mxus v3 motor? Could the axle move in stator for some reason during regen/throttle drive? Thanx in advance.
I have never worked on an MXUS. On the 50mm hub motors, the bare axle gets pressed in with over 3000psi of pressure, so I would HIGHLY doubt that it would have any play. Having said that, quite often when I order custom wide axles (from both Zelena Vozila and QS Motor), the bare axle fails QC at the factory and they have to machine the axle(s) again. I have often wondered what aspect of the axle failed QC--perhaps the diameter where it meets the stator? Regen sure does apply a lot of backward forces. Enough to loosen tightly applied M16 axle nuts. If I had to guess, i would say that you are NOT getting ANY play where the axle meets the stator. I would have to guess that your axle is rotating back and forth just a smidgeon in the dropouts. I see that you say that you have precisely fit torque arms and tight axle nuts, but I wonder if there isn't a LITTLE bit of play there between the axle flats and the dropouts. If it were the case that your axle wasn't pressed tightly enough in the stator, it would stand to reason that the problem would get worse over time, what with the acceleration and deceleration. Is the problem getting worse? Is this problem bad enough to require repair, or is it just irritating and perplexing? As is always the case, a troubleshooting shortcut is to "remove and replace". Expensive as it may be, you could acquire a SPARE, equivalent rear wheel and substitute it in to see if the knocking problem persists. I love remove and replace as a troubleshooting shortcut, and there may come a day when you are so happy to have a spare, ready to drop in.
Thanx for wide answer, the value of pressure and advices. I appreciate it. The "knocking effect" is not getting worse with time and it is rather annoying and confusing. Anyway it is not a healthy sign. I use this motor for 3-4 months now. Axle nuts are not getting loose, they are checked regularly. I'll check if there is play on axle - torque arm joint. Would you please give me rough dimensions of stator ring? I'd like to convert 3000 psi to maximal torque the axle - stator joint can transfer. The torque needed to get "knock effect" is quite small maybe 10-15% of max motor torque. Outer axle and inner stator ring dimensions would be helpful as well. Actually difference of the two. Regards.
I have twelve of these motors, but none are taken apart now so I can't measure the stator for you. I do have six bare axles. I measured the diameter of these bare axles where it presses in to the center hole of the stator. The average diameter of six axles is 28.00mm. The 50mm motor will produce up to 150Nm of torque. I still can't imagine that your knocking problem is due to slippage between the axle and the stator. Remember there is a centering pin that goes in the axle and stator (seen at 18:10 in this video). Installed correctly, this pin is very tight in its place, but I suppose that some play (slippage) would be possible if the pin and/or the axle were made too small. Are you sure there is NO play whatsoever where the axle flat meets the dropouts? If so, you must have really tightly fitting dropouts and torque plates! If you figure out the problem, post the solution here as I am curious.
Thanks. Calculating friction force of stator - axle joint, theoretical torque needed to move the sleeve on the axle is not much larger (almost the same) then maximum motor torque from datasheet. Therefore if there is any imperfections in manufacturing of the axle, sleeve or wedge, then it could lead to play over time. I will be checking torque arms soon. As quick as I find the woodpecker I will let you know. I just got the answer from my body Barmal (he designed nice FOC sinus controller), and he posted me a film, where new mxus motor axle can be moved in a stator with one hand. It is just loose.
Vladimir S. of Zelena Vozlia: email epmpartner@yahoo.com or www.zelenavozila.com or QS Motor email info@qs-motor.com Email them and ask very nicely if they will make you some axles. Don't be in a hurry.
I need to find a video on how to disconnect the wires on a scooter hub motor simply so I can replace the bearing... I've been all over the web seen videos in dam near every language but English... And the only videos I found in English it's actually a guy from India so he may as well be speaking Swahili... It has been 6 & ½ months since my bearings went bad. All the seller wants to offer for help is sell me another motor. I could use some suggestions... Anyone.?
It's always been called a woodruff regardless if it's the Half-Moon shape or not. And I've also seen it called the other way regardless if it's a half moon shape or not.... just depends on where you are and what you're working on and reading.
Ah zip-ties, because the flat iron linkage in the puller was bend the wrong way around the hinges to actually pull the bearing. Expected one of you to get bruised in your first attempt.
He pensado de hacer eso pero no tengo tiempo. Yo trabajo tantas horas en mi trabajo regular y cuando tengo tiempo libre yo prefiero trabajar en mi garaje.
It would be probably be a lot more helpful if you knew what the parts were actually called instead of making up terms on the fly. Just sayin. Helpful video nonetheless
You really made it hard for yourself bringing the Stator out: Push Stator through - when it’s almost out you can lift the rotor up by hand, bringing it all the way to the top of your Press. Now you can loosen the press again and take the rotor away - now you can bring the rotor down and take it away. What’s screeching is the unsupported rotors magnets connecting with the Stator at one point. Totally normal. Even though very very nice work - those were just my two cents! I was really enjoying your video! :)
Splendid Video, clean and clear! Great job !
So I had an old e-bike hub motor that was causing issues cutting out, so I took it apart it was very rusty so I give it a good clean and also renewed the soldering joints of the hall senses, my question is I saw somewhere on eBay some guy selling some sort of silicone fluid that's supposed to help transfer the heat from the coil to the permanent magnet aluminum body of the wheel is this needed? I'm thinking to just use lithium grease
Very interesting. I need to replace the hub wiring pony tail, mine got stretched and no longer sends power to the hub. Is there a network of professions that do this kind of work in the Indianapolis area? I don't feel qualified, but every bike shop just wants to replace the hub in its entirety.
Thanks! I don't own an ebike but my brother does and I get tasked with maintenance and repairs... nice to know what all is involved long before it's ever necessary. Will definitely check out your other vids!
I do my cycle repairs myself and don't have many essential tools and I often say that if only I had a third arm things would be so much simpler. Glad to know I wasn't alone
You're pretty honest up until the end and I commend you for that and I want to say thank you... but when you were putting it back together. you were pushing the stator out. When you were putting the first cover on. you didn't really explain how you got the stator to go back in when put the others cover on or really even how you got the stator back in in the first place. You just kind of said it was a pain. And please call the stator a stator not a stader. Driving me nuts calling it a stader. Oh and FYI if you ever have to take a hammer to something that is a stud or has threads. put the nut on it until the nut is almost flush. then use a block of wood or brass and you'll be good to go. you can beat on it pretty hard without messing up the threads. I'm an automotive tech and just wanting to learn about electric motors. Thanks for the video greatly appreciated.
I don't see why it had to come that far apart! Why not just remove the side covers, and press out the Axel? Any reason besies the weight?
Will the motor spin if I don't have the side cover bolts in? Because I had to replace the hall sensors for a friend and everything went well, Now I'm going to power everything up and see if the error code is gone and the motor spins. But he never gave me any bolts for the side covers, I'm not sure if they need to be screwed in place to hold something so the inside can spin, or if it will be ok to test for movement without them. Then he can install the bolts when I return it to him. Thanks
Hi man.. i'm from Verona Italy.. thanks for your nice video i would like to understand more about hub motors. Basicly the rotor Is made by magnet and Is It arranged external for stator?
Thank you for the video I was wondering about this as my drop out is 170mm and I’m trying to switch out my frame to a frame with a 155mm drop out. If you don’t mind me asking where do you get the replacement shaft?
21:44 I would have liked to see you put the magnetic stator together with the casing... I imagine it's pretty violent the way it comes together? Kinda dangerous "keep fingers clear!" kinda thing? ...........actually........come to think of it......... why did you separate them in the first place? you don't need to in order to get the axle out, right?
I was ready to film it, but there were only two of us in the shop for this task which required both of us. Next time I do it, I will film and post the event.
Thanks. Is there anyway to replace the axle without using a hydraulic press? Unfortunately I do not have access to one.
How do you go about rejoining the stator/cover. I saw another videos where they line it up and let it snap shut. Looked like you could easily damaged the magnets?
Thank you for making this video!..
Where do you buy replacement axles and what are they called to to buy one
when assembling the bearing in thr motor cover, the sleeve should be small so that it rests on the bearing's inner diameter. The way you are doing it, the pressing force is transmitted through the ball bearing which damages it. Moreover, while doing this operation, the whole motor should rest on its axle and not on the 4 small columns. the way you are doing it, the forces are trabsmitted to the driving axle through the ball of the rear ball bearing... You want the forces to be transmitted directly from the inner ring of the upper ball bearing to the driving shaft. It is not all at the right way to assemble a bearing. That is why you feel the "spring" forces due to the cover deflection which should not be involved at all in this operation.
I was waiting for one of those sockets to go flying at about mach 9 and take out some teeth.😬 Not only that it looked as if the windings were being pushed out and distorted. 😬😬
hey end what when cover heve space from one side ? i don't now why from one side i heve a little space end i can't make screw the cover pls answer
My motor is stiff turning. It's a mountain bike wheel 48 v 1000 w is stiffness normal?
Where could I buy an axle at?? The threads stripped out on mine because it's cheap Chinese metal..!!!
fairly impressive construction
Hi, I bought a brand new xiaomi himo z20 ebike and it's just 25km since brand new. I recently hear whining noise when the bike is under 15 kmh and the noise disappear when the speed is above 15 kmh. Would you have any idea what I should check in my case? Thanks so much.
Can't get to your website ,Google Surveys blocking it!! Was wanting to know where to get an axle at??
Ok, no problem. Once again i appreciate your help especially with the smaller size gear puller for the bearings which is something i overlooked.
why do you dont seal the motors to protect for water ?
Great video. Thanks. I'm trying to troubleshoot a hub motor. Should my three motor wires have continuity? How can I test, with just a multimeter?
If you testing the hail sensors you put your ground wire from multi meter on the sensor ground. You put the red lead on the blue green green or yellow wires and turn the wheel by hand. You should get a voltage reading. Repeat the process for each wire then again for all sensors. If any show no reading at all then you have a faulty hail sensor
Could I send my motor to use to replace my axle if you still do it
Hmmm, what happened to the most difficult bit, getting the rotor back into stator without losing your fingers?
no need to stick your fingers between the rotor and stator
Where do you buy axel?
I disassembled a older 500w Heinzmann. It was really difficult to get in and I had to 3d print myself a custom disassembly mounting.
I have a Bafang 750 watt/48 volt Brushless, Geared Hub Motor with a 190 drop out axle where the motor cable comes out through the axle. I also need to change the axle because of damaged threads, Would the process be almost the same? I realize there are planetary gears inside to change. Do you know where I can obtain a replacement axle? Thank you.
Try Luna Cycle.
@@industrialebikes4956 Thank you
Why use silicon as a gasket? Why not simply waterproof the motor with red insulating varnish? If humidity is caught inside the motor (e.g. heat buildup will suck in water as it is not completely sealed) it needs to exit ... I have seen many a motor with drilled drain holes. Nice video.
Actually, it's not a Woodruff Key, which looks to all like a slice off of a coin. The key used (although loose-isa) can be made a bit more secure by running a series of dot punch marks on both sides and being tapped home.A slight chamfer on the starting side would also help.Or you can shim it with S.S. shim cut to pack out the key
Where do you buy a spindle from bin looking every where
thanks!
for future reference, there called Woodruff (or half-moon) keys, used a lot in hydraulic motors, and hub assemblies, advantage of the Woodruff key is the elimination of milling near shaft shoulders. An additional advantage is a stuck key can be removed from a shaft with a hammer blow (not prying out), the circular profile will push the key out of the slot, as opposed to a standard key which will need to be pushed axially. If you've ever used a self feeding wood chipper, you kept a few in your pocket ;-)
what is the size of that stator please and how thick ? thanks
Reading these comments it appears most everyone is a complete know it all with recommendations on how to do everything the right way. Pulling hub motors apart is a pain,and the cromotor is the beast of all beasts. Good job but for the love of God it's called a stator.
A new axle can be made at any local machine shop if they have something to copy. Stator Removal can be done with any $20 gear puller from Harbor Freight. As for pushing out the axle and pushing in an axle, perhaps a vehicle jack would work but it may be hard to build a suitable holder, but the machine shop would have a hydraulic press for sure. I am just wondering what the cost would be for a new axle, push out old, push in new. I'd want a larger route for phase wires.
Then you gotta worry about the cover plate bearings. I just did bearings on mine and it was easy. So maybe the machine shop could easily cut out a larger hole on cover plates, add larger bearings.
What gauge of motor (i.e. phase) wires do you have now? What is the diameter of the copper? Are you wanting to draw a great deal of current? If so, how much current at what voltage?
The machine shops around here (Bay Area, CA) always ask for a drawing because it is all CNC work. When I have not had a drawing, I hired them to make one. They would have me approve the drawing (via email) before machining the parts.
8:25 You're using the adjustable wrench wrong. It should be flipped so the pressure on the nut-flat is exerted by the bottom of the sliding piece.
Good point! Makes sense. Thanks.
@@industrialebikes4956 After you press out the axle, would it be possible to push in a bushing with a torque arm (something like a bushing with a flange that could be bolted to the frame) to convert it for through-axle use? Unfortunately I haven't seen any detailed plans of the motor dimensions to see if this would be possible before ordering a chicom motor to modify. I have access to a metal ship with a press, lathe, mill etc. to make the bushing part.
The Ball I can’t imagine that there is any room for a torque arm (base mounted) in the motor. If you figure out a way, I would be interested to see what it is.
@@industrialebikes4956 I don't have any plans/technical drawings to check the diameter of the axle
The Ball If it were me, I would go with the tried & true method of mounting the torque plates outside the motor.
Thanks your video about hub-motor. welcome your visit. thank you.
Are 500 watts hubs the same size as a 1000 W Hub...??
Hi, thanks for sharing your experiences. I need to replace my cromotor bearings. What are the best replacements for off road use? Would you know the size/model/manufacturer of best bearings to get?
Thanks
Andrew
The answer is "6204-2RS". I have UKS brand now, but any quality brand will do. SKF is the highest quality. In any case, 6204-2RS bearings will fit perfectly. I apply up to 3000 psi of pressure on the hydraulic press.
Industrial Ebikes ,,,, thanks for your reply. 6204 for both bearings?
Yes, both sides use a 6204 bearing.
Industrial Ebikes ,, thanks again for making the effort to reply. You've been really helpful. Great detailed video, its encouraged me to crack open my cro for the first time. Happy New Year!
You too. Do you have a hydraulic press and bearing pullers?
Hi have you ever had the up motor casing break I've had my in less than 12 months and it's making a vibrating sound and the case it looks broke all round
No, I have never had that happen.
Thanks for posting this, I am new to Ebike converstions. My first build had a catastrophic failure last night, the hub sheared around the axle causing the wheel to lock up. I shot a little video trying to show how it failed, but it's behind the gear cassette and hard to see. I would like to upgrade to a heavy duty hub that can handle my 300+ lbs. Do you sell or repair hub drives?
I HAVE THE SAME EXACT FAILURE!! However for me it was not because 300+ lbs but instead because I heavily abused it riding down rocky mountains at high speed ...
i guess you can either get a stronger motor cover? or mount the hub motor as a mid drive, using the 6 bolts to mount a gear onto
im confused on how the stator and cover works. So when you apply throttle, does the cover start spinning around the stator? Does the cover just hover around the stator because the magnetic field keeps it from hitting the stator? How does the hub motor rotate?
The motor cover (not to be confused with the side covers) has magnets glued on the inside of it. Also, the outside of the stator has magnets glued to it. Under power, the outer magnet (assembly) rotates around the fixed inner (stator) magnet (assembly).
As it happens, the side covers are bolted to the motor cover. As such, the side covers rotate with the the motor cover. This is why each side cover has a bearing inside it. Interestingly, the bearing on the drive side is pressed into the freewheel flange. The freewheel flange is bolted to the side cover.
Think of it like this: the axle is bolted into the dropouts, so the axle is not going to rotate. The axle is pressed into the stator, so the stator is not going to rotate either. The motor cover and side covers will rotate, however. This is fortunate because the rim is affixed to the side covers via spoke tension.
The outer magnet spins around the fixed inner magnet.
Industrial Ebikes ohh ok i understand how it spins now. But what keeps the motor cover magnets from hitting the stator magnets. There's some bearing preventing it from hitting each other? Or is the magnetic field strong enough to keep the motor cover from hitting the stator
The motor cover magnets do not hit the stator magnets because there is empty space in between the inner and outer magnets engineered into the design. The motor cover magnets are glued to the motor cover. The motor cover is bolted to the side covers. The side covers extend outside the physical reach of the inner magnets, and the side covers are anchored to the bearings on either side.
Industrial Ebikes i know theres empty space between the magnets on the cover and stator, so essentially, it's the bearing that keeps them apart?
Industrial Ebikes lets say you have a ball and a ring is surrounding the ball, kind of like the planets in our solar system. The ball is the stator and the ring is the motor cover. But if you push the ring, it'll hit the ball. The thing pushing on the ring is actually the bike tire connected to the spokes connected to the motor cover. So what prevents this outer ring from hitting the ball.
When you assemble any two parts with silicone or any form-a-gasket material...apply a very thin film of grease with your finger to one of the parts and silicone to the other part...so the next time you won't damage mating faces by banging a screw driver in between...
Good advice!
Where do I get an axle from help
It probably wouldn't have helped in this case but next time you need to pound on something with threads on it, spin the nut on it and hit the nut not the threaded shaft itself mushrooming the end and damaging the threads. interesting vid tho, thanx!
Good tip!
Did exactly that and damaged the nut and threads. It usually works to protect the threads but not when the forces are too great.
Loosen in a star pattern? Why?
I suppose there is no need to loosen in a star pattern. I am just in the habit of tightening in a star pattern.
@@industrialebikes4956 Where can I buy an axle at.?????
Quick tip when using a jaw puller...use a ratchet and socket,it's much easier.
Hi ya, could someone explain how the freewheel works in this motor? Thanks!
In tradition, the force is transmitted to the freewheel in cassette from pedaling and drive the rear wheel. But in e-bike, the source of power is the motor isn't it? So how will the freewheel work in this case?
David Kk The axle is pressed into the stator. Being rigidly bolted to the frame, the stator remains in that position at all times. The outer magnet spins around the stator. The motor cover, side covers and rim are rigidly attached to the outer magnet. The motor power causes this outer magnet to rotate.
The bearings lie between the axle and the side cover. This allows the wheel to roll freely in either direction if the motor is not under power.
If the motor is under power, the bearings allow the wheel to rotate under power.
@@industrialebikes4956 Thanks for your explanation! Glad to learn some engineering knowledge!
Where can buy an axle ?
I have all styles of new, bare Cromotor axles. Text to (707)293-8973.
@@industrialebikes4956 I want to buy a axle for a 1500 w.Motor csc is the brand size 190mm
My 250w motor won't work at all any ideas what to check ?
I would start with a remove and replace. If you replace it with the exact same motor, your nonoperational motor will be a source of spare parts even if you can’t fix it. The first thing that I always check is the connections in the wiring. Beyond that, you could look at removing and replacing the Hall sensors.
Best thing about remove and replace is that you get back on the road faster.
These motors are not expensive. You can get into the nonoperational motor at your leisure. And like I said, those spare parts will likely be a gold mine down the road.
A really helpful video BUT you didn't show hw to reset the stator in its cover without chopping off fingers and getting a straight set.
There were two guys in the shop that day. Both of us had our hands full when we put the stator back in the outer magnet, so nobody was available to film it. My buddy held one part, I held the other part, and we kept our fingers out of the way and slowly got closer to each other until POW! The two magnets mated.
This is very informative. Thank you!
My pleasure. Happy wrenching and safe riding to you.
Any possible way to do this without a gear puller?
You could make a tool specifically for the job, and that may work better because the OTC 1038 gear puller used in the video has very fat teeth on the jaws. The fat teeth require the user to pry open the motor side cover at least 10mm in order to get the bearing puller in place. Make sure to pry up the side cover evenly; using two people working 180 degrees apart from one another works well.
Personally, I use the (smaller) OTC 1023 for the exposed bearing and the (quite large) OTC 1038 for the side cover. These cost $41 and $62 respectively and they will last you a lifetime. As far as seating the bearings, a benchtop hydraulic press can be purchased for as low as $75. It is crucial to seat the bearings completely; I can accomplish this using less than 1500 lbs. of hydraulic pressure.
I rebuild these motors a lot, and it is aggravating enough using the job specific tools listed above. It takes a fair amount of time in order to get the large bearing puller on the side cover, but once it is on it is smooth sailing.
I usually slap in a fresh bearing because a 6204-2RS bearing only costs about $3.50.
I think you could have exchanged the axle while keeping the rotor in place. I did not bother you...
Why didn't you re-seal it ?
I forgot to do so.
@@industrialebikes4956 Where can I get an axle at...!!!
By the way, I saw a video of some guys working on a hub drive in china...they beat the whole assembly on the ground to get the side cover off!!! haha! I think your way is much better.
LMAO
hello my motor was water damage I need to replace hall sensor , can you help me?
Yes. Send me an email. My email address is erikmannie@gmail.com.
Industrial Ebikes hello the sensors arrive I sent you an email 5 minutes ago with some photos thanks for your help
I replied to the email.
That's a lot of work!
Can you open mine .It looks like that one 1500 w
😋I took my 1000w hub motor apart with a 9$ puller and used the force of the magnets to seat the bearing and replace the housing.Risky loosing a finger is very easy must be so careful⚡that was 3 years ago to repair i must do it again😕
We open mine was easy.Now I need to buy axle .Where can I find the axle 190 mm .
Yo...you didn't need to take the rotor (magnet side) off to press out/in the shaft. That was a needless risk, especially the way you wedged the plastic in against the stator coils.
Farther on, you're trying to press the bearing/flange on and there's nothing but the magnets holding the stator in...you can see it pressing out through the bottom. You're also pressing on the wrong part of the bearing; in this case you should be pressing on the inner race, against the shaft, while the shaft is locked in place. You're damaging the bearing and it's going to wear out a lot faster. In the next scene, you can see the stator sticking out quarter of an inch because the bearing hasn't been seated fully.
Then you go an press on the other side in much the same way, and even result to using the screws to try and suck it in the last few millimetres. That's one reason you had such a hard time screwing it down. The bearings still aren't seated fully, you've just made the casing bulge out.
Some good info here, but some bad techniques. Anyone doing this, leave the rotor on & press the bearings on properly. Go watch some videos about pressing on car wheel bearings if you need to know where to apply pressure...don't force the pressure through the bearings themselves; you'll wreck it.
if you showed how disconnect the speed sensor inside . you would get alot of views
A heat gun on that cover for a couple minutes would expand the bearing seat in the side case, would pop right off.
Thermodynamics👍🏼
it might ruin the insulators.
Hi, is there any chance that the axle could be loose in the stator? I mean not playing loose, but I have knock when I push throttle after breaking with regen. The same knock I feel when I breake with regen after acceleration. I do not have rear brake caliper at all. I have proper, precisely fited torque arms both sides and nuts on axle are very strong tighten. Is the axle assembled same way in mxus v3 motor? Could the axle move in stator for some reason during regen/throttle drive? Thanx in advance.
I have never worked on an MXUS. On the 50mm hub motors, the bare axle gets pressed in with over 3000psi of pressure, so I would HIGHLY doubt that it would have any play. Having said that, quite often when I order custom wide axles (from both Zelena Vozila and QS Motor), the bare axle fails QC at the factory and they have to machine the axle(s) again. I have often wondered what aspect of the axle failed QC--perhaps the diameter where it meets the stator?
Regen sure does apply a lot of backward forces. Enough to loosen tightly applied M16 axle nuts.
If I had to guess, i would say that you are NOT getting ANY play where the axle meets the stator. I would have to guess that your axle is rotating back and forth just a smidgeon in the dropouts. I see that you say that you have precisely fit torque arms and tight axle nuts, but I wonder if there isn't a LITTLE bit of play there between the axle flats and the dropouts.
If it were the case that your axle wasn't pressed tightly enough in the stator, it would stand to reason that the problem would get worse over time, what with the acceleration and deceleration. Is the problem getting worse?
Is this problem bad enough to require repair, or is it just irritating and perplexing?
As is always the case, a troubleshooting shortcut is to "remove and replace". Expensive as it may be, you could acquire a SPARE, equivalent rear wheel and substitute it in to see if the knocking problem persists. I love remove and replace as a troubleshooting shortcut, and there may come a day when you are so happy to have a spare, ready to drop in.
Thanx for wide answer, the value of pressure and advices. I appreciate it.
The "knocking effect" is not getting worse with time and it is rather annoying and confusing. Anyway it is not a healthy sign. I use this motor for 3-4 months now. Axle nuts are not getting loose, they are checked regularly. I'll check if there is play on axle - torque arm joint. Would you please give me rough dimensions of stator ring? I'd like to convert 3000 psi to maximal torque the axle - stator joint can transfer. The torque needed to get "knock effect" is quite small maybe 10-15% of max motor torque. Outer axle and inner stator ring dimensions would be helpful as well. Actually difference of the two.
Regards.
I have twelve of these motors, but none are taken apart now so I can't measure the stator for you. I do have six bare axles. I measured the diameter of these bare axles where it presses in to the center hole of the stator. The average diameter of six axles is 28.00mm.
The 50mm motor will produce up to 150Nm of torque.
I still can't imagine that your knocking problem is due to slippage between the axle and the stator. Remember there is a centering pin that goes in the axle and stator (seen at 18:10 in this video). Installed correctly, this pin is very tight in its place, but I suppose that some play (slippage) would be possible if the pin and/or the axle were made too small.
Are you sure there is NO play whatsoever where the axle flat meets the dropouts? If so, you must have really tightly fitting dropouts and torque plates!
If you figure out the problem, post the solution here as I am curious.
Thanks.
Calculating friction force of stator - axle joint, theoretical torque needed to move the sleeve on the axle is not much larger (almost the same) then maximum motor torque from datasheet. Therefore if there is any imperfections in manufacturing of the axle, sleeve or wedge, then it could lead to play over time.
I will be checking torque arms soon. As quick as I find the woodpecker I will let you know.
I just got the answer from my body Barmal (he designed nice FOC sinus controller), and he posted me a film, where new mxus motor axle can be moved in a stator with one hand. It is just loose.
I have a E bike hub that I would like you to work on I live in Concord California can I ship it to you for it to be worked on?
Give me a call or text at (707)293-8973. I live in Santa Rosa, but I am going to Vallejo every day this week, including Saturday!
Where do you buy motor axles?
Vladimir S. of Zelena Vozlia: email epmpartner@yahoo.com or www.zelenavozila.com
or QS Motor email info@qs-motor.com
Email them and ask very nicely if they will make you some axles. Don't be in a hurry.
here in Brazil costs a lot of money. send one for me can be used or refurbished.Thank you friend
Buy one on Alibaba.
Industrial Ebikes $700+impostos 60%👎
What is your opinion on the ones that can be found in alibaba and other chinese sources? Are they really poor quality?
motor bike here in Brazil comes out around 1300 dollars
You can buy a QS Motor on alibaba. Those are great!
Suru sa anat tak batho ki hub motor kasa Banti ha
I need to find a video on how to disconnect the wires on a scooter hub motor simply so I can replace the bearing... I've been all over the web seen videos in dam near every language but English... And the only videos I found in English it's actually a guy from India so he may as well be speaking Swahili... It has been 6 & ½ months since my bearings went bad. All the seller wants to offer for help is sell me another motor.
I could use some suggestions... Anyone.?
It's called a "woodruff key" not an alignment pin!!
Would have been a good time to add statorade/ferrofluid
wow bro so nice
18:11 It's called a woodruff key. Now when you lose or destroy one, you know what to look for =D
I think that is a round end machine key. Woodruff is a quarter circle shape. Machine keys are essentially square.
It's always been called a woodruff regardless if it's the Half-Moon shape or not. And I've also seen it called the other way regardless if it's a half moon shape or not.... just depends on where you are and what you're working on and reading.
Why do you keep saying "between the 2 magnets or get the 2 magnets apart"? The rotor is not a magnet.
It's a rotor, not a cover! On a hub motor, the rotor is on the outside.
That’s what she said 😁
Ah zip-ties, because the flat iron linkage in the puller was bend the wrong way around the hinges to actually pull the bearing. Expected one of you to get bruised in your first attempt.
Mande um para mim de presente.aqui no Brasil custa$700.00......pode ser usado ou recondicionados....
Exelentes videos haci los hacieran para habla hispana
He pensado de hacer eso pero no tengo tiempo. Yo trabajo tantas horas en mi trabajo regular y cuando tengo tiempo libre yo prefiero trabajar en mi garaje.
48v 750w motor repear
Here's the video... any input is greatly appreciated. Obviously I want to get back on the trails! ua-cam.com/video/QqGKrKpwxQ8/v-deo.html
These pins do not work well; they cannot perform correctly their task. I tried 2 times and for both times I broke them. Disastrous. Flat land pins.
Can I send my Bafang hub motor to you for repair ? Simply quit running.
YOu forgot to reapply sealant.
That is correct: I forgot.
good evening sir please i can have your facebook account?
I am definitely not on Facebook. I don’t know how anybody has time for that. That is time that could be spent working in the shop or riding a bike!
Omg this is so aggravating. I guess you need to rebuild it. Otherwise, I hope you'd use a hammer and some force instead of that hydraulic press.
I don’t think a hammer would work. You need slow, steady pressure. A hydraulic press doesn’t cost very much money.
Not stattor, stator (“Stay-ter) nice work though.
It would be probably be a lot more helpful if you knew what the parts were actually called instead of making up terms on the fly. Just sayin. Helpful video nonetheless
So I just need to buy a hydraulic press now, eh?
water tight needs it silicone
. . o O ( ... I should buy a hydraulic press )
WHAT THE FUCK AM I WATCHING WOW HOW TO DESTROY THE ENAMEL OF A WINDING LOL
CRINGEEE. Some of your choices of surface to press on are rather questionable. Other than that great video, thanks.
Its easier to buy new hubmotor
)))
motor bike here in Brazil comes out around 1300 dollars👎
What size gear puller do I need for a 10 1/2" hub? I see 12" but i'm led to believe they will not pull a 10 1/2" hub. Great video!
A 12” gear puller would be perfect. 12” refers to the maximum size.
Iya ya Allah.