Noisy Cute q100

[RyanTo]

I just put a cute q100 201rpm rear hub kit on my girlfriend's bike. I am running it at 12s lipo 44.4v and it has a bad resonance noise that I hear at 5-7 mph. I can feel it vibrate the bike as well. Sometimes I'll even hear a metal chatter somewhere in back(I'm not sure if it's the motor, it might not be). It doesn't really help if I ease the throttle as I just hear it longer, It does help a little if I peddle through the 5-7 mph mark. It was present before I had the wheel trued and after.

It's using the standard (I think ku65 controller) that came with it. It sounds pretty quiet when it get above 10 mph and even seems relitivly quiet going up a small hill at 10+ mph. The spokes on the wheel are not touching each other. They are all taught as I just had it in the shop to have the wheel tuned. I can't really think of anything else to do except to take apart the hub? I'm not really sure what to look for though..

 

[motomech]

It sounds like it might be running sensorless.
If that's not it, it's a very easy to take the cover off and pull the motor out for a visual inspection.

 

[RyanTo]

Is there a good way to check if it's running sensorless, or what would cause that? It was kind of a strange kit. The 6 prong connector that goes to the motor wasn't assembled I had to put the prongs in the houseing. I hooked up and color matched all the wires. I see in their diagram it has phase a, phase b, and phase c. They are all hooked up. Should they be?

Motor wire(3*Φ4 bullet holes)
Yellowhase A; Green: Phase B; Blue: Phase C - All hooked up

Motor hall sensor wire(6P Plug)
Red :5V; Black:GND; Yellow:Hall phase A;Green:Hall phase B;Blue: hall phase C - Also all hooked up

Should I have only one set of Phase wires hooked up?

 

[motomech]

Those little pins are little devils. They tend to back out unless you made sure they are secure by pushing them is with a tiny screwdriver.
I would recheck all your sensor connectors if I were you.

 

[RyanTo]

Rechecked and all looks good

 

[winkinatcha]

Hmmm Like Motomech says, an intermittent hall connection could be doing this, tho the consistancy of the noise happening at a certain speed is kinda differnt... and motomech's comment about running sensoreless Does kinda make sense...

Couple of other thinks to check, could your derailler be rubbing against the motor, or your free wheel be just a little too tight against the hub,? Possibly only being a problem at certain speeds due to the gear you are peddling in?

Joe

 

[motomech]

Rechecked and all looks good : /

Disconnect the hall sensors and test ride it to see if anything changes. If it's the same, test the Halls.
There is a "dirt floor" procedure to test the halls without the tester. Search the posts of Oakwright for the best out-line of how to do this.
If all this checks out, youn really need to pull the motor. It couldn't be easier. Take out the three phillips screw in the cover and then the cover unscrews. I gripped the cover in a WorkMate and turned the wheel. You can repack the bearing whikle you are there.


Edit-These are really cheap controllers so I suspose it could be faulty. No way I know to test it asides from trying another.
Where do you live?

 

[RyanTo]

Interesting, I found the post here.

viewtopic.php?f=2&t=36752&p=538199&hilit=+hall#p538199

Reading those posts I have some more things to try tonight. I'm in Portland, Oregon.

 

[RyanTo]

It didn't make much of a difference unplugging the halls. I was hoping it had something to do with the controller running sensorless but it's hard to tell. Also, it seems to be getting more of a metallic sound and I probably haven't drove it even 5 miles. I tried to open the motor the other night, took out the 3 screws, but was unable to twist off the cover.

 

[RyanTo]

I made a video so you can hear the sound. The phone was in my shirt pocket:

http://www.youtube.com/watch?v=SBeMXowCcEE&feature=youtu.be

 

[motomech]

The fact that nothing much changed when you disconnected the Halls would indicate that they are not working, you would notice the difference.
And it sounds louder than mine even before the metallic vibrating noise.

How to test the Hall system;
With the white plug connected-. If your multimeter had good thin tips, you should be able to slide them into the backend of the plugs while it is all assembled. Set your multimeter so it's set to measure voltage, somewhere in the 5 volt range. Stick the red one alongside the red wire, and the black one alongside the black wire. You should measure 5 volts. If not, there is something wrong. After that, stick the red probe into the green wire, black to black, and turn the wheel very slowly. About every inch or so of wheel movement the voltage should toggle between 5v and 0v. If it doesn't toggle, there is something wrong. Then put the red to blue, black to black, and move the wheel slowly to see if it toggles. Repeat for yellow.

You should always have a constant 5v coming from the controller on the red wire. You should have the Green, Yellow, and Blue wires alternate between 5v and 0v. Always sink the black probe to black when testing the halls.

F.M.I.-which kit do you have? Volts, wind and wheel size

 

[RyanTo]

I'll have to get a volt meter, it sounds easy enough. It's a q100 36v 201 rpm in a 26" rim. I have it running on 12s.

 

[aaronlim]

I am now having the same problem with both my 36v 201rpm and 328rpm. Did you manage to fix it? Having tried 2 motors on the same wheel, I conclude that 36v q100 is rubbish. My 24v 201rpm is fine.