hub motor stutter/judder doesn't move

pdooley

10 W
Joined
Mar 10, 2014
Messages
65
Location
Tampa, FL USA
Ebay 48V 1000w kit. Worked fine for 2000 miles. All the sudden I apply throttle and it doesn't provide driving torque, just does a herky jerky movement you can hear and feel.

What should I check first?
 
Sudden judder in an otherwise working ebike is usually due to some wirer connector coming loose for some reason. As Icewrench stated, check that all your wires, fat ones and skinny ones. Make sure that they are all connected properly. Connectors can go bad over time. Check them carefully.

Another juddering like issue I have had in the past is when the hall sensor in the throttle went bad. In that case the throttle might be fully off or fully on with nothing in between.

You have also opened a thread asking for a good throttle to recommend.

Was it your throttle that caused the problem?

:D
 
you're on to me. :D
tWQOajTEUBwDTW4Yb_pv-79LhA-6b4efnysR5wuQzjg=w702-h395-no

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another concern was I rode in the rain and the 5-wire connector got wet and bike died. I blew it dry and all was fine.
but this is different. sometimes bike will start to move like an inch then stop and the shudder occurs.

I'd love to get that $80 Italian throttle but for now it looks like Ali Express. Probably get 2 to have a spare.

thanks
 
Hummm....doesn't sound like a throttle issue to me.... Either phase wires (the three fat ones) or hall wires (five skinny ones) not doing their thing. Or worse yet, a short in the wheel itself.

Sounds like it is time for some investigation.

Four questions:
Did you check all your connections?
What were the results?
How good are you with electronics?
Do you own a digital multi meter?

:D
 
the wire plug from the throttle to controller got wet last week. I discovered some corrosion in the pins. Cut the plug off and soldered the wires direct. No difference.

plugged/unplugged the remaining connections but no difference.

The broken throttle still works when held in the right place and twisted. Just the motor is making some weird noises, like it's fighting itself.

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Good enough with electronics it look like. 8)

As long as you got all the wires properly soldered to the proper wires. If something got crossed then it could cross up your phase / hall wire sequence which could cause the motor to judder.

Your photos look like the Hall wires (small wires) are properly connected, but make sure that your Hall sensor wires are all connected to the corresponding colored wires, do this......

Unplug the phase wires, those are the three fat wires (green, yellow and blue?) and spin the wheel to see if it spins freely, or if it coggs like the juddering you felt.

If it spins freely then we will need to test the Hall sensors in your wheel via the wiring and a multi meter.
If it still coggs then we will have to test for an open short in your phase wiring with a multi meter.

:D
 
i'm not an EE but I know a bit about electronics.
i have a couple meters, even a fancy Fluke 77.
what value should I be looking for on the hall sender(s)?
i guess a wiring diagram would be helpful. but these kits are probably pretty standard, just need to do some research.
 
Not a value in the halls, but you need to know if they are flipping from 0 volts to around 4.6 volts. But that is later. First disconnect your phase wires (three fat ones) and spin the wheel.

What does the wheel do when you spin it with the phase wires disconnected?

:D
 
e-beach said:
First disconnect your phase wires (three fat ones) and spin the wheel.

What does the wheel do when you spin it with the phase wires disconnected?

:D

Wheel spins, comes to a stop due to drag. I disconnected the read brake to make sure it wasn't contributing.
With the phase wires disconnected, exact same. No strange noises, spins freely.
 
Get yourself an ebike tester. They're cheap and great for helping track down problems like this. It sounds like a hall wire connection issue to me. If the spades are easily removed from the connector, note the positions, and take them out and clean them off. Then without the connector, slide them in and out of the controller side of the connector a few times to ensure a good connection, and give it a try.

Do you have a drip loop on the motor harness (a mandatory part of ebike installations often overlooked)? If not, then water will follow the harness like a river channel and into your motor. It can even migrate inside the wiring into the motor, so you may have water inside the motor. Put a mark on the cover and on the rotor ring, so you can put the cover back on in the same position, and then pop the cover. If you have the axle installed in the wrong position, the halls could be at the bottom and bathed in rusty water which would cause the symptoms you have. That's worst case, but possible.

Is there any damage to the motor harness? That could have broken a hall wire and be the issue too.

Hopefully it's just a bit of corrosion on a hall spade causing the problem, or a drop or two of water still in the connector, since those are the easiest issues to fix.
 
John in CR is right on all accounts. An e-bike tester from ebay is inexpensive, and nice to have around. I agree that it seems like a Hall sensor issue now that we have eliminated a phase short in the wheel. By spinning your wheel while it was disconnected from the controller showed that you do not have a phase wire short circuit in your phase wiring.

But while you are waiting for your ebike tester to arrive from China, and before you open you hub motor, because that is a big job the first time, you need to test the Hall sensors as shown in the Grin Tech hall sensor link above.

Make sure your battery is fully charged.

Connect your battery to your controller.

Have all the hall wires (all five skinny ones) connected properly.

Get a pencil and scratch paper around to write down the voltages so you can post them here.

Test the red and black (input voltage) wires to see if you have around 5volts. (4.5v or there-abouts is ok)

Leave the black wire (ground) connected and then test the other three (return) wires, with the red probe while very slowly spinning the wheel. You are attempting to get the Halls to flip as the positive and negative faces of the magnets pass them. The color of the wire insulation may differ from the Grin Tech colors, what is important is that you test all three to see if the Halls are turning on and off properly.

As the magnets slowly pass the sensors, your meter should switch from 0v (or near 0v) to about what your input voltage is.

Let us know how it goes.

:D
 
drip loop, huh? if this is mandatory, why am just hearing about it now?? why didn't somebody call me? :D
makes perfect sense. the axle is hollow and leads right inside the motor. probably good to prevent water intrusion.
i noticed surface rust on the ID of the axle leading into the motor after a couple wet rides. Now I'm having nightmares of slushy, rusty water swirling around inside my motor.

So I followed along and tested my halls. Didn't know they were halls until reading this, but that makes sense too. B/c motor is brushless it needs multiple windings and must energize them in proper sequence.

My 5 wire connector has red/black/yel/blue/grn wires.
red to black- 4.28V
black to yel/blue/grn- all approx the same- .03V to .04V off, 5.00x on. By 5.00x i mean 5.004, 5.003, etc. very close to exactly 5v.
That seems a little strange though, since the input is only 4.28V, but I'm not sure exactly how halls work.

One other thing I tried was switching 2 of the field wires. Like that, the motor did not make the shudder but just locked. I spun the wheel by hand then applied throttle and the motor acted like a brake, stopping the wheel immediately.
Connected properly, the motor still locks but makes the protesting shudder noise/vibration.

I guess I'll dust off the road bike for tomorrow's commute. I'm gonna miss my electric assist.. :cry:
 
OK, moving up the line,

To review.
With all phase wires (field wire) connectors detached the wheel spins freely. No short circuit. With phase wires crossed, short occurs and and the wheel locks.

Hall sensors tested and switching properly. So you Hall sensors are performing properly.

All wires visually checked so no cuts that might cause a problem.

Sounds like you may have blown a mosfet in your controller..... :(

Did your controller get wet?

Can you borrow another controller to test your motor?

I would love to tell you how to test your controller mosfets, but I am afraid I am not that good in that department.

Hummm....you didn't tell us who was the seller of your setup. Who did you purchase you kit from?

Also, can you post pictures of your controller so we can see what you have. Just keep the file size under 500kb so you can post them.

And of course the million dollar question, is you battery fully charged and balanced? Sorry I took so long to ask.... :oops:

:D
 
Let me make sure I'm testing this right-
3 big wires attached or detached, wheel spins freely, with the same drag it has always had since new. tried with power on/off, no change.
i reversed 2 phase wires so the motor spun opposite direction. motor locks either way, just going forward it shudders as it locks.
Controller has gotten wet about 4 times. It has a rubber seal, so I assumed it was ok. I can open it and visually inspect the board.
I have no spare controller to borrow, but I can buy one.
This was an Amazon kit. Seller name was "commercial bargins".
The exact listing I purchased is gone, but similar is here: http://www.ebay.com/itm/New-48V-100...680?pt=LH_DefaultDomain_0&hash=item4178d22eb8
I run 12s lipos at 4.15 per cell, so I have enough V.
P2L_XYPJ6t5RQ8jqjqgQnmQhAUJQO13LwzmqduaOU1g=w368-h207-p-no

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looks like I'm riding this old girl tomorrow
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did the hall sensors toggle up and down on all three? the motor does spin freely if the phase wires ae disconnected but heavy chugging if it has the phase wires connected and is that better if you disconnect one of the phase wires , test each one, or if you disconnect two phase wires?
 
Halls are fine and phases aren't shorted, so most likely the controller. Disconnect the ebrake to make sure it isn't somehow causing the problem, and check the 0-5V output from the throttle. Since you have plenty of rain riding you should definitely pop the motor cover and check inside, because water in the motor could have caused the controller failure. Pick up some good anti-corrosion spray to give it a treatment while you have it open. Note that water can get sucked into the motor even with drip loops an good sealing, since the motor will always "breathe". ie when it warms up to operating temp the air inside will expand, and then when rain cools it the air contracts and sucks water in. Some of the hardcore all weather commuters go to the extent of installing a drain plug.
 
Opening a hub motor the first time is not for the faint of heart, but if it is to be done, check out the video below to see how it is done.

Also, here is a waterproofing a bike thread for you to look at:http://endless-sphere.com/forums/viewtopic.php?f=3&t=39507

As for controllers, they are water resistant not water proof. You should open your controller and see if anything is visibly wrong. Also take a couple of pictures of the top and bottom of your opened controller and post them. Make sure they are in good focus.

[youtube]vrUjPNIs348[/youtube]

:D
 
that video was very helpful. i have a vise and gear puller so the job isn't that bad. Only thing is the gear puller is cranked pretty tight and the hub is not coming off fully. I don't want to tighten the puller any more for fear of breaking my hub flange.
A little tapping will probably free it up, but my neighbor's master bedroom is close by my garage, so that will have to wait till tomorrow.
The controller looks a little crispy on the shunts and one mosfet on the end looks like it got wet at one point.
My throttle is 6 wire, so i need to figure out which 2 to check for the 0-5k ohm test.
How do I test the mosfets in the controller?

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do not take the motor apart if there is nothing wrong with it. it can be tested without opening it and in fact is easiest to test while still intact.

test the mosfets in the controller by using the diode tester on your DVM to test the body diode of the mosfet. the hiside mosfets have the drain attached to the P+ lead, the big red wire, of the controller.

the loside mosfets have the source leg attached to the ground or P- of the controller. the phase wires are connected in between, to the source leg of the hiside mosfets and to the drain side of the loside mosfets.

use the diode tester and put the red probe on the red wire of the controller and the black probe on each of the phase wires. they all should be open circuit. reverse the leads so the black wire is on the P+ lead and then test each of the phase wires with the red probe. you should see the 400mV of the body diode on each phase wire.

do the same to the loside mosfets. put the black probe on P- and then put the red probe on each of the phase wires. they should all be open circuit. then reverse the leads and put the red wire on the P- lead and then put the black probe on each of the phase wires. each should show the 400mV of the body diode.
 
In this situation one of these is really useful, as you can diagnose a problem in a few mins without having to take everything to bits :
http://www.ebay.co.uk/itm/E-bike-Scooter-electric-bike-motor-controler-tester-rower-elektryczny-/261631751279?pt=LH_DefaultDomain_212&hash=item3cea77b46f
 
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