What's making this grinding noise on my electric Chinese vespa
My girlfriend bought a electric Chinese vespa from a so called dealer in Encinitas, ca...SCAMMER, and it's making a grinding noise from the wheel well. It worked o.k. for two days (not including the same grinding noise mr. voisen claimed was "normal"...LIAR), but the second night we had it it just lost power and wouldn't go unless pushed off first, and even then went slowly (plus the grinding noise). She was going downhill when it happened as well so it couldn't have been too heavy a load, and I just wanna fix it without having to buy all new stuff and rewiring it myself.
I am posting a link to some awesome video for you to watch and hope that one of you guru's might have seen (heard) this before and can help me diagnose the issue.
Thank's for watching and would appreciate any/all help I can find.
Ouch! That sounds very bad. With the chinese controllers, because they are square wave controller, you should expect a "buzz" from them, but NOTHING like this!!! What a shame because its a great looking scooter.
No as for your noise, it definetely sounds like the hall sensors are not working and causing huge amounts of current to enter the motor at incorrect times giving you this grinding sound. I've heard a lot of motors with broken hall sensors but this sounds far worse, it nearly sounds as if the motor windings have de-laminated (come unglued) and are vibrating. If you follow the cables coming from the hub motor you will have 3 THICK wires for power, and 5 THIN wires for your hall sensors. Some motors have a "spare" pair of hall sensors so you may have an extra pair of 5 THIN wires coming from the motor. If you do, unplug the old one and plug in the new one and you should be fine and cost you nothing. Otherwise you may need to open up the hub motor and replace the hall sensors. There are 3 hall sensors (small transistors) and only cost a few dollars each. But it does require a good level of electrical knowledge.
Let us know how you go.
I can't watch the video at the moment (at work, morning break), but my motor just this week also lost all power and made grinding noises like mad. One of the hallsensors had gone bust, but thankfully in my motor a second set is installed. After having taken the rear fairings off it was just a plug-and-play thing for me, as the hall sensor sets are all grouped into one connector each in my ride. it may be similar in yours.
Careful about calling people a liar. It is quite true that the cheaper BLDC controllers uses sqaure wave commutation and especially at low speeds and high currents will always be noisy.
I am at work at the moment and cannot view your U-tube either. Can you post a pic of the bike? And what model is it? I have the 4000li and it has always made a brief noise at startup which immediately goes away at any speed above 2mph. I am at 11,807 litterally trouble free miles. Original set of lithium cells.
Re: the video: That's NOT normal! The bottom line is that there is something wrong, and it's probably inside the wheel.
I would double check to make sure that all the Hall connections were intact between the motor and controller. If they are (and if you in fact don't have a second Hall-effect pigtail provided), I would take it back to the vendor.
PLEEZE be nice. These vendors are ordering this stuff from China for us. In many cases, yes, they may wish we would just go away. But give him or her a chance. You are actually lucky to have a real person to talk to; many scoot owners (myself included) have never even seen what city their scoot was drop-shipped from. As I understand it, a container load of scooters usually comes with a certain quota of spare parts. Try to get permission for an A-B test with another wheel motor. It might have to be scavenged from another scoot.
If in fact you can't get cooperation from your vendor, these wheels DO come apart, and once they are apart, they CAN be fixed.
Yikes, that sure sounds like more than just a broken hall sensor! I second Mark's notion of talking to the vendor you got it from, and remain friendly but firm in the process.
Are there any unusual mechanical noises when you just push the scooter, without applying power?
It looks like you are about 200% more competent than the "average Joe." With Chinese electric scoots, that's a good thing.
I have no idea how to test a controller either. I would do an A-B test with a known good one.
Your observation about the relay brings a thought to mind: perhaps there is a resistance in the pack wiring. When the controller "opens the floodgates" to power the motor, the resistance causes the voltage at the relay to drop so far it cuts out.
I replaced all the power side wiring on my XB600. The original had been wired with 14 gauge wire and crimped connectors. I switched to 10 gauge and soldered/crimped connectors.
My suggestions are a followon to my earlier point about low voltage cutouts happening:
After looking at your circuit diagram, I would put a digital voltmeter on the 72V line into the controller. You shouldn't see any voltage drop when you open the throttle. You can also check the measured voltage drop in the battery cables, as well as a physical inspection of wiring terminations and battery fastenings.