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?
1st, thanks for all your 411 everyone. 2nd, the vendor will not be an option. That being said I have done this:
I took the 72v 1500w motor off and hooked it up to a 48v sensorless controller (with connections for hall sensors), battery pack and throttle (all made for a bicycle and 48v) and the wheel powered very smooth, no noises (though slower and needed a push to get it going). We also opened the motor up and inspected the windings and there was no cracking of insulation, no bluing or areas that looked like it had been shorting or overheated, just surprisingly clean, so we put it back together again and ran it off the bench again like before, still smooth.
I took apart the controller and there doesn't seem to be any burnt areas either but I am not sure where to look or how to test anything?
Note: The scooter is wired with 6 12v lead acids for 72 volts of power, wired so that the ignition switch does not turn on that huge 72v connection, it uses a 36v three pole power relay (big electric switch) to connect the 72v controller power. To activate the power relay the battery pack is separated to make 36v and gets sent through the ignition switch, which also runs through a 36v/12v dc/dc converter to power the lights and all other 12v stuff. I had no idea what I was doing when I dove head first into this, and so hooked stuff up a little wrong when I went to put the motor back on the scooter after testing it. I didn't fry anything but i did have it wired so that the coil that powers the relay was getting powered to activate, but as soon as it activated it cut off its own power (so it would slightly open and close over and over again really quick).
The thing is that the relay coil, upon power on and power off, back and forth quickly like that, made a sort of mini grinding noise exactly like the scooter makes.
I am going to bench test the hall sensors but how can I test the controller? I checked all of the connections and they seemed to be tight and conductive, could it be something else? Would the throttle do that? Also thinking about battery strength under load, maybe they're weak, but how could I test that?
The batteries do read 72/73v with the multimeter....
No, no noises when we push it without power, only under throttle
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.
Ok, so I finally got a wiring diagram for getting the correct voltage to the right place at the right time without frying anything WHEW,
but now I hook up the controller to a known 72v hot (and ground) and no zap of capacitor fill up. Also I measure voltage coming from the power wire for the hall sensors and no voltage reading, also no voltage from the controller to the throttle, should be about 5v on red.
I just need my thinking confirmed: that power going in should result in power coming out of the controller right?
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.
Thanks, I did that and found strong 80v from the hot into the controller but no five out to the throttle, no power to the wheel either, aaugh! I also didn't hear that shock your supposed to when power is initiated to the controller, loading up the capacitor, wondering if it got fried, can you fry those things, they're like a little battery right? Anyway I am ordering a new 72v 1500w controller from Zenid and pretty sure it will work. I am just afraid it will do exactly the same thing as the old controller. If it does the same thing I am going to try what you said with the throttle and possibly test the batteries under load.
I will keep posting.
Have you ever seen anything like the wiring diagram on any other electric rides, I hear that all Chinese scooters are wired differently and was curious as to how they did it? I am finding myself very interested in all the possibilities and would like to see more.