Is this a noise or just a sound? (Solved)

[MattZ]

My first build, it's made this sound from the start but I'm not sure it's something to be concerned about or not. I've never ridden or even seen another ebike so I don't have anything to go on. There's about 50 miles on it now, everything seems to work fine. Motor, controller, connections, battery do not get hot while riding. It only makes the sound under acceleration or heavier load uphill. No load top speed is 45mph. I have it limited to 25 to ride, which it does no problem.
Bike has a 1200w QS DD hub motor, KT 36/48v 15A square wave controller, 48v 20Ah battery.
There were issues in assembly. Motor phase wires had 2 colors changed: blue wire had green heat shrink and the green wire had blue tape wrapped around it. I connected it assuming the changes were there for a reason (green heat shrink to green wire from controller, etc). The motor would lock up, no rotation. I checked for cogging by touching phase wires together, it seemed fine. I then checked voltage of hall sensors which also seemed fine.
I found the really helpful BLDC wiring flowchart located here https://endless-sphere.com/forums/download/file.php?id=197293&mode=view and went through that and got it working. I did not change phase wires, only hall sensor connections.
It sounds like a spray paint rattle can but describing a sound is tough so I uploaded a short video
https://youtu.be/kjylK7Fo_JU

So is that sound normal or should I keep going through the flowchart?

 

[MattZ]

Maybe read though this post and see if the symptoms sound similar. The answer in this case was wheel bearings.

https://endless-sphere.com/forums/viewtopic.php?f=3&t=112890

You're correct on the combos.

Yes I've been following it closely since the start. He's was getting a single click / creak when he hit full throttle. My noise is constant under load, and more of a ringing sound. I was going to try and change the bearings, I still might but I can't feel any play and there's only 100 easy miles on this bike. He had marks on the magnets from the rotor. When I had the motor apart I put on magnifying glasses and couldn't find any scrapes or scratches. After the noise being almost constant for 100 miles I'd think there would be some evidence. But bearings are relatively cheap and worth a try.

I can tell you that in my experience the phase wire color combination, motor side vs. controller side, will MATCH when it comes to the hall wires. It's about the firing order. The phase color firing order must match the hall sensor firing order.

"Do you know if I'm correct in my assumption that for every color combination of phase wires there will be one correct combination of hall wires? I kind of recall reading that somewhere but I'm not certain."

I say you need a controller.

I had to read that a few times for it to sink in. The hokey 'blue tape on the green wire' motor I have throws things for a loop.
I'd been thinking of upgrading the controller to a sine wave version before I even realized the noise wasn't supposed to be there.

I heard back from the seller with more fairly useless advice:
"Our engineer went through the videos you provided. His explanation is:
This set is using higher quality QS motor (better than the other ones), the phase setting is different than others. Most likely the noise came from the wrong phase. Can you try to do the following:
Swap the green and blue wires on the hall sensor connector (the white connector on the motor wire) and also swap the green and blue phase wire (on the motor where the end is the ring). It might get rid of the noise."

Thankfully I got the higher quality motor, I don't know what I'd do otherwise.
I doubt their advice is going to get rid of any noise and it's almost inconceivable that I haven't already tried the combination they suggest. Although to eliminate the chance of skipping a combination I've made a spreadsheet of the 6 possible phase wire combinations and 6 possible hall wire combinations for each phase combination. I might take the time and go through all 36 possible combinations.

 

[nicobie]

I might take the time and go through all 36 possible combinations.

I think that's a good idea. It's really the only way to know for sure that it's wired correctly.

I once had a motor sound similar to what you are experiencing. It had a short in the windings that I only found after opening the motor. Even then I had to look hard for it.

Good luck!

 

[ZeroEm]

Compared to most here, i'm new at this. Unless I get a motor and controller combo that plugs in and works. I don't even look at the color of the wires and do the boring step by step testing until I find the best combination.

 

[MattZ]

I might take the time and go through all 36 possible combinations.

I think that's a good idea. It's really the only way to know for sure that it's wired correctly.

I once had a motor sound similar to what you are experiencing. It had a short in the windings that I only found after opening the motor. Even then I had to look hard for it.

Good luck!

Well I can attest that there are 6 smooth rotation combinations out of the 36 possibilities. 3 forward and 3 reverse. Unfortunately none of them resulted in quiet operation. At this point I'd be happy if it went backwards quietly.
Short in a winding? I'll never find that, it looks like a lot of wire. But maybe checking resistance isn't a bad idea, I'll have to look into how that's done. I did the cogging test and that seemed fine.

 

[ZeroEm]

Keep us updated. We will all learn something.

 

[MattZ]

Progress at last, although not of a technical nature. The seller has finally relented and agreed to replace the motor. Hopefully he'll work with me to shorten the 3 week turn around time to do that. Glad I looked high and low to find a US based seller to avoid this particular problem.

 

[kenl]

Progress at last, although not of a technical nature. The seller has finally relented and agreed to replace the motor. Hopefully he'll work with me to shorten the 3 week turn around time to do that. Glad I looked high and low to find a US based seller to avoid this particular problem.

what a pain to go through when it was so obvious for a replacement in the first place. Glad you got there.

 

[MattZ]

Progress at last, although not of a technical nature. The seller has finally relented and agreed to replace the motor. Hopefully he'll work with me to shorten the 3 week turn around time to do that. Glad I looked high and low to find a US based seller to avoid this particular problem.

what a pain to go through when it was so obvious for a replacement in the first place. Glad you got there.

Thanks! It's a huge relief. Seller says he'll have someone ship it Monday instead of waiting till 9/12 when he returns from a biz trip like he originally planned.

 

[MattZ]

New motor arrived today, I hooked it up and it's making the same noise as the original hold motor. I have a new sine wave controller on the way but I don't think that's the problem since I hooked this motor up to a different bike and it made the same noise although not as loud or as long. The different bike has a sine wave controller, the noisy bike doesn't.
The motor is a QSMotor 1200w and I'm beginning to think it's some sort of design flaw. If I tap the motor housing with a small wrench it rings loud and long-ish like a bell. The other bike just makes a metallic thud.
Unfortunately the controller is coming from China, couldn't find a comparable one in the states.
The new motor arrived like the first one, looking brand new in factory packaging, with blue tape on the green phase wire and green plastic on the blue wire. It seems to me the manufacturer knows there's a problem with the design and they're trying to lessen the noise by switching a couple wires around which isn't doing the trick.
When I started building an ebike I never thought I'd be thinking about installing a muffler, but that's where I'm at now. I'm going to try putting a leather strap around the center of the hub. Bad for heat I'm sure, but I'm determined to get to the bottom of this.

 

[nicobie]

If you tried it on a different bike with a different controller I'd be looking closely at the spokes/rim.

How bizarre. This is a new one to me.

Good luck

 

[MattZ]

If you tried it on a different bike with a different controller I'd be looking closely at the spokes/rim.

How bizarre. This is a new one to me.

Good luck

I checked the spokes and they all feel tight, unlike the original motor which had a ding in the rim from shipping and 1 loose spoke right at the ding. Tightening it didn't solve the noise.
I would think if there was some weird resonance in the rim the tire and tube would muffle it. It sounds the same with the tire on the rim and off.
The sound was different when connected to the other bike, a short ZING compared to a ZIIIIINGGGG. Other bike is 52v compared to 48v in addition to the sine / square difference. I assume it just gets to steady state, less load speed quicker.
I'm grabbing at straws at this point, googling phase angle mismatch, BLDC motor demonic possession, planetary alignment, etc.

 

[ZeroEm]

demonic possession

:lol:

 

[justlooking808]

did you ever try to test the controller to see if one of the fets is burnt out/grounded? this guys video is what i used to troubleshoot mines : https://www.youtube.com/watch?v=lTssCn5YyTw . sounded much more worse than yours, but a new controller fixed it. square wave controllers have that jabbing sound to it and it sounds like one of your fets on the controller is slightly blown or grounds out when it heats up a bit.

 

[MattZ]

did you ever try to test the controller to see if one of the fets is burnt out/grounded? this guys video is what i used to troubleshoot mines : https://www.youtube.com/watch?v=lTssCn5YyTw . sounded much more worse than yours, but a new controller fixed it. square wave controllers have that jabbing sound to it and it sounds like one of your fets on the controller is slightly blown or grounds out when it heats up a bit.

Thanks. I did "test" it but not in the way he shows in the video. I have 2 bikes, the noisy one (wife's) and a silent one (mine). They both have same brand controllers except mine is 52v sine wave, hers is 48v square wave. I have them set up with the same connections so I was able to put them next to each other, disconnect her motor from everything on her bike and connect it to everything on my bike. It made the same sound, but not as loud or for as long. I believe because it gets past the acceleration state faster due to higher voltage. It's not a heat thing, her controller barely gets warm after riding for an hour, and it does it immediately under no load while cold.
I think the seller bought a bad batch of motors since he was nice enough to replace it but the new one does the exact same thing when connected to either controller. Both are marked QSMOTOR 20200415.
I have a sine wave controller for her bike on the way that I'm expecting any day now. If that doesn't lower the racket to a tolerable level I'm just going to have to find a different motor.

 

[justlooking808]

did you ever try to test the controller to see if one of the fets is burnt out/grounded? this guys video is what i used to troubleshoot mines : https://www.youtube.com/watch?v=lTssCn5YyTw . sounded much more worse than yours, but a new controller fixed it. square wave controllers have that jabbing sound to it and it sounds like one of your fets on the controller is slightly blown or grounds out when it heats up a bit.

Thanks. I did "test" it but not in the way he shows in the video. I have 2 bikes, the noisy one (wife's) and a silent one (mine). They both have same brand controllers except mine is 52v sine wave, hers is 48v square wave. I have them set up with the same connections so I was able to put them next to each other, disconnect her motor from everything on her bike and connect it to everything on my bike. It made the same sound, but not as loud or for as long. I believe because it gets past the acceleration state faster due to higher voltage. It's not a heat thing, her controller barely gets warm after riding for an hour, and it does it immediately under no load while cold.
I think the seller bought a bad batch of motors since he was nice enough to replace it but the new one does the exact same thing when connected to either controller. Both are marked QSMOTOR 20200415.
I have a sine wave controller for her bike on the way that I'm expecting any day now. If that doesn't lower the racket to a tolerable level I'm just going to have to find a different motor.

aww that sucks man, good luck on your troubleshooting. i know my square wave controller just makes that horrible sound(but not as loud) when under load, but when i put it on a sine wave, it goes away. i do have both controllers on a slow start now and it's almost gone as when under load, it slowly goes up to speed. but either way, best of luck to you and your Ebike.

 

[MattZ]

aww that sucks man, good luck on your troubleshooting. i know my square wave controller just makes that horrible sound(but not as loud) when under load, but when i put it on a sine wave, it goes away. i do have both controllers on a slow start now and it's almost gone as when under load, it slowly goes up to speed. but either way, best of luck to you and your Ebike.

Thanks again. Yeah, my silent bike is louder now that I blew up the sine wave controller and grabbed the only suitable controller I could get quickly, but it's square wave. Also waiting on a new sine wave controller for that one too. It never ends. I could probably fix both of them in an hour if it didn't take a month to get a replacement part.
I looked at the settings I have available (on KT brand controllers) and didn't see slow start, only one that requires pedaling before throttle will work.

 

[justlooking808]

aww that sucks man, good luck on your troubleshooting. i know my square wave controller just makes that horrible sound(but not as loud) when under load, but when i put it on a sine wave, it goes away. i do have both controllers on a slow start now and it's almost gone as when under load, it slowly goes up to speed. but either way, best of luck to you and your Ebike.

Thanks again. Yeah, my silent bike is louder now that I blew up the sine wave controller and grabbed the only suitable controller I could get quickly, but it's square wave. Also waiting on a new sine wave controller for that one too. It never ends. I could probably fix both of them in an hour if it didn't take a month to get a replacement part.
I looked at the settings I have available (on KT brand controllers) and didn't see slow start, only one that requires pedaling before throttle will work.

i know, it's been a month and a half since i ordered my controller and it's still stuck somewhere. almost time to open a lost item case. :lol:

for the setting for slow start, i believe it's the C5 setting. your's is sent to 10 as max amp pull/no limit as soon as throttle is pushed. i believe it's 00, 01, 02 where each setting is different. from my understanding, 00 = three phases before max current pull, 01 = two phases before max current pull and 02 = one phase before max current pull. think of each phase being something like 00 = each phase being 25% current pull in each phase, 01 = 33% current pull in each phase, 02 = 50% current pull in each phase. from what i can tell, from feeling only, each phase last about 3-5 seconds and it's always that way. you can feel it even when you try to push the throttle when the bike is in motion, you'll have a slight delay. i have mines set to 00 or 01 for a smoother riding experience and knowing that the fets aren't just on/off pulling full power, but get a slow and gradual start pulling less power. if that makes any sense.

 

[markz]

Yeah be sure to check your email.
I got an email from delivery company that my over-sea's order is stuck in customs on the other side of the country, upon intake to country at customs depot its held, they are awaiting duty payment to release shipment.
Its been there for a month with an email every 1 week from delivery company.
I used an email I hardly ever use.
So I emailed the company I bought it from saying its not delivered and got an auto response, emailed them again and received a human response with a tracking # linked to shipping company and the purchase company stated I was suppose to have been messaged by shipping company, anyway I clicked on the tracking link which led me to shipping company and got all the info. Called shipping company up and wihtin 1 minute talking to a thickly accented outsourced c.s. rep probably in East Asia, my guess Bangladesh India.
I never got a tracking # on my receipt when I ordered. Normally I pay duty at my front door when its delivered. I guess Chain Reaction Cycle is in Ireland, North (Part of Brexit UK, Dublin) or South (Part of EU) I dont know, and dont know if Chain Reaction Cycle is apart of Brexit or not. Brexit has royally screwed up the UK and I feel sorry for the duped Brexiteers.
But $56cdn + $14cdn duty for bicycle parts.

So thats a story on shipping, customer service and import duty for you.

i know, it's been a month and a half since i ordered my controller and it's still stuck somewhere. almost time to open a lost item case. :lol:

 

[justlooking808]

sorry, just read somewhere P1 setting, if you leave it at default 100 seems to work better then setting it any lower. could you try that and let me know the outcome?

 

[E-HP]

sorry, just read somewhere P1 setting, if you leave it at default 100 seems to work better then setting it any lower. could you try that and let me know the outcome?

Where are you getting this information on the P and C settings?
P1 is motor specific, and is used to determine and display speed. It won't' affect performance, except if the maximum trip speed is set to something less than the normal maximum speed of the motor. Since the OP's motor is direct drive. P1 would be set to 1 (1:1 gear ratio) times the number of magnets for the motor (usually 46 for a 9C clone).

 

[justlooking808]

sorry, just read somewhere P1 setting, if you leave it at default 100 seems to work better then setting it any lower. could you try that and let me know the outcome?

Where are you getting this information on the P and C settings?
P1 is motor specific, and is used to determine and display speed. It won't' affect performance, except if the maximum trip speed is set to something less than the normal maximum speed of the motor. Since the OP's motor is direct drive. P1 would be set to 1 (1:1 gear ratio) times the number of magnets for the motor (usually 46 for a 9C clone).

i was reading controller reviews on some site and saw that two people mentioned almost the same thing as the op. they said that the P1 controller setting affected how the motor ran if set correctly and had better results with the default 100 value. although can't remember if they had DD motors or not. i just figured it was worth a quick try and see if that solves anything. it's just changing one setting. but i guess not.

as for the C5 setting, i looked at multiple display setting for the KT controller and almost all of the one's that i was interested in, had that definition for the C5 Setting. not sure what display he has, but from looking at all the settings, it seems similar to what i was reading. unless it's very different for DD motors, then im clueless.

 

[ZeroEm]

I seen people trying to squeeze out more power. Think this is a carry over from automobiles. They think they can change the setting and get better performance. We know how to do it. Get you a 50lb motor and 5lb controller and 70lbs of battery and have at it.

 

[MattZ]

Noisy bike has an LCD3 and what I assume is 'downlevel' firmware since it doesn't have the L settings. The other one is LCD8 with the L settings.
I'm willing to try anything at this point to quiet that motor down. For our last 2 evening rides I've had one of those heavy duty solid rubber bungee cords wrapped around the hub between the spokes. I know it's not good for shedding heat but that motor barely gets warm and it does quiet it down some but it's still in the 'super annoying' range.
I'll play around with that C5 setting. I don't know how I overlooked that slow start with it set to 1, 2, or 3. I assume my eyes went straight to 'max current' and figured that's obviously the one for me. I don't think I could tolerate a delay, but a ramp up might be OK. I'll give it a try.
P1 is where it was set when I got it, I've never changed it and the 'magnets x reduction ratio' is my understanding of how it's supposed to be set. I should probably count the magnets just to be sure it doesn't have some weird number of them. I have a close up video of the magnets with motor open and turning slowly by hand from when I was looking for any sign of rotor / stator contact so I can count them without opening it up.
C2 is a baffling setting, the description is "C2 is motor phase classification coding setting, it is served as identification parameter of different phases of the motor when using sine wave drive and the default value is 0.
When C2 setting is 0, indicating that the used Quantum motor phase is an ordinary one.
When the setting is a certain value, indicating a particular motor phase is used. C2 setting
range is 0-7"
I've never seen the phrase "quantum motor phase" anywhere other than KT controller manuals so it's a mystery. The default setting was 0 on both a square wave and sine wave controller. It might be worth messing with.
It would be so nice if the manuals had more detail. Some settings are straightforward not needing much explanation, but the more esoteric settings have vague descriptions.

 

[MattZ]

I seen people trying to squeeze out more power. Think this is a carry over from automobiles. They think they can change the setting and get better performance. We know how to do it. Get you a 50lb motor and 5lb controller and 70lbs of battery and have at it.

So are you saying my idea of a 5 mile long extension cord won't work? Back to the drawing board...
I think you have the 'most power' camp, the 'most range' camp, and the 'something's not right here and it could be one of these settings because I've tried everything else' camp that I'm in. Once I get that ironed out I'll probably look for more power or range, or at least look to have a better understanding of the settings so I can adjust them to better suit a ride if I'm going somewhere hilly vs. flat.
That cheap-ish temporary controller I got is an 18 FET vs the old 12 FET and man what a difference, hills are no problem now. Trouble is it's not compatible with my display so I'm flying blind. I assume my range has dropped considerably.

 

[ZeroEm]

:lol: Was not talking about you. Setting up your new controller. Sorry is it seemed so. Mostly had my brother in mind and some others posting of late. The want to take a 250-350w setup and change the hidden settings that stop them from getting that 2000w and 40mph out there 36v 10a controller.

by MattZ » Sep 15 2021 10:05am

ZeroEm wrote: ↑Sep 15 2021 8:33am
I seen people trying to squeeze out more power. Think this is a carry over from automobiles. They think they can change the setting and get better performance. We know how to do it. Get you a 50lb motor and 5lb controller and 70lbs of battery and have at it.
So are you saying my idea of a 5 mile long extension cord won't work? Back to the drawing board...
I think you have the 'most power' camp, the 'most range' camp, and the 'something's not right here and it could be one of these settings because I've tried everything else' camp that I'm in. Once I get that ironed out I'll probably look for more power or range, or at least look to have a better understanding of the settings so I can adjust them to better suit a ride if I'm going somewhere hilly vs. flat.
That cheap-ish temporary controller I got is an 18 FET vs the old 12 FET and man what a difference, hills are no problem now. Trouble is it's not compatible with my display so I'm flying blind. I assume my range has dropped considerably.