Newbie query

JimN

Finding my (electric) wheels
Sep 15, 2019
8
1
I was tempted by how cheap it was and have attempted a Voilamart front wheel conversion on one of my (seven) cycles (including two recumbents) - age telling (I am 66) and looking to the future. But it doesn't work - the LED display lights up nicely but nothing from the motor. I have tried disconnecting everything from the controller but the essentials ( ie disconnecting brakes, pedal assist and leaving the power, motor, and throttle) .. it makes no difference. And I am puzzled that I can only shift the wheel an eighth of a turn before it locks - is that usual?
 

JimN

Finding my (electric) wheels
Sep 15, 2019
8
1
Oh, and although there is a nice full sign on the display, there is also a red "empty"? battery sign there as well. What does that mean?!
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
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With the battery removed/physically disconnected, can you turn it then.....
regards
Andy
 

JimN

Finding my (electric) wheels
Sep 15, 2019
8
1
No, it makes no difference. Is that not normal then? I was a bit puzzled when I put it all together as I wondered how it would freewheel but I assumed that some sort of magic would take place
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
If you can turn the wheel when it's disconnected, but you can't when it is, that means that you have a short between the phase wires somewhere along the line from the motor connector to the controller.

Have a look to see if the bullet connectors at the controller are touching. If that's not it, there's a fair chance that you've blown a MOSFET in the controller, which happens when you give the motor full power when it can't run, like if you have the wrong motor connection sequence.
 

JimN

Finding my (electric) wheels
Sep 15, 2019
8
1
Thanks - that is helpful as I am more than beginning to think that the unit was faulty when it arrived and I need to return it. No, it makes no difference either connected or disconnected .... I have never been able to turn it more than a fraction of a rotation. And there is no sign of any power getting through when connec"ted". Presumably when disconnected there is normally little resistance, if any - is that right?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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OK, I misunderstood what you were saying. Let's be sure. Disconnect the motor completely and make sure that the three phase wires can't touch each other. If you still can't turn the motor, there's a short circuit between two of the phases. The place to look is where the cable comes out of the motor. If it does turn, you have to find the short at or further up from the connectors. It's very simple to find where the problem is with a meter. Do you have a meter? You shouldn't be considering an electric bike conversion without one.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
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OK, I misunderstood what you were saying. Let's be sure. Disconnect the motor completely and make sure that the three phase wires can't touch each other. If you still can't turn the motor, there's a short circuit between two of the phases. The place to look is where the cable comes out of the motor. If it does turn, you have to find the short at or further up from the connectors. It's very simple to find where the problem is with a meter. Do you have a meter? You shouldn't be considering an electric bike conversion without one.
When a 3 phase motor is shorted in some way (or in fact almost any electrical motor, DC or AC, single phase or 3 phase is shorted), it resists turning to some degree, but it will turn.
This used in many sittuations to brake and prevent runaway, it is called "Dynamic Braking!" There is a reasonably accurate description on Wikipedia for anyone interested.
But it happens only if you try and turn it quickly, that the resistance to turning will be noticed more. The motor has to produce some voltage as a generator, which it can only do while turning, and the short produces a huge "load", braking the motor.
If power was still being supplied, in some obtuse manner, then it could possibly feel locked. Though I personally have never experienced that, only read about it.
But this sounds more as though the motor is "mechanically locked" (If I understood the OP correctly), almost as if something is obstructing the wheel/motor.
I am totally guessing, but maybe possibly a motor bearing is badly damaged....causing the problem. Or some other failure in assembly!
I would be MOST interested to find out what the final cause was eventually, such problems interest me greatly! This one is to my mind, quite unusual....
I tend to feel that a replacement unit may turn out to be the easiest and best fix, as I myself would not want to ride on a bike that had exhibited such a problem as described, without knowing the "whole story!"......
Best of luck for a speedy fix,
Andy
 

Woosh

Trade Member
May 19, 2012
20,373
16,875
Southend on Sea
wooshbikes.co.uk
I was tempted by how cheap it was and have attempted a Voilamart front wheel conversion on one of my (seven) cycles (including two recumbents) - age telling (I am 66) and looking to the future. But it doesn't work - the LED display lights up nicely but nothing from the motor. I have tried disconnecting everything from the controller but the essentials ( ie disconnecting brakes, pedal assist and leaving the power, motor, and throttle) .. it makes no difference. And I am puzzled that I can only shift the wheel an eighth of a turn before it locks - is that usual?
you should post some pictures so that members can have a better idea where the problem may be.
Take the chain off to reduce the number of possible cases.
Check also in both directions.
If you have a direct drive motor and can only turn one eighth of a turn, it looks like you have a detached magnet jamming the rotor.
If that is the only problem, open the motor and glue the magnet back.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Rather than jump in and try to solve every possibility at once or confuse the guy with complicated theory, it's much better to take things one step at a time. Shorted phase wires is by far the most common reason that DD motors lock, and it's very easy to confirm or eliminate by simple quick tests. If it were my bike, or somebody presented the bike to me, I'd have the answer within 30 seconds.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
78
you should post some pictures so that members can have a better idea where the problem may be.
Take the chain off to reduce the number of possible cases.
Check also in both directions.
If you have a direct drive motor and can only turn one eighth of a turn, it looks like you have a detached magnet jamming the rotor.
If that is the only problem, open the motor and glue the magnet back.
Excellent idea, all for it, except that as it is brand new, never run, that motor should be replaced by the seller I feel, not repaired by the "buyer". Which could possibly negate any further guarantee....
Andy
 

JimN

Finding my (electric) wheels
Sep 15, 2019
8
1
Oh dear, thanks to everybody - and such a LOT of help ...... when the problem has turned out to be that I. as the OP is / was an idiot. Sorry to all (Voilamart included, as it is not their fault). The clue came as I started to dismantle it all to return it, and loosened the wheel bolts. Strange, I thought, I have only made a couple of turns and the wheel runs freely. Oh b .. r, tightening the bolts brings the drop-out lower mudguard fixing (which projects inwards just a little) into contact with the bolts on the disc brake attachment on the wheel. Which explained the partial rotation and the mechanical blocking. I don't have disc brakes, so simply taking the bolts out should have fixed the problem. Certainly the wheel runs smoothly now ...........
But it still doesn't work - display lights up showing full, but with an odd red ?fault light. Looks like an empty battery signal ... but that makes no sense.
I think this is a result of a separate, earlier, idiocy when I made some error in connections and I suspect fried the controller. So I will replace that and make no returns.
Unless anybody has other ideas?
 
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Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
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Oh dear, thanks to everybody - and such a LOT of help ...... when the problem has turned out to be that I. as the OP is / was an idiot. Sorry to all (Voilamart included, as it is not their fault). The clue came as I started to dismantle it all to return it, and loosened the wheel bolts. Strange, I thought, I have only made a couple of turns and the wheel runs freely. Oh b .. r, tightening the bolts brings the drop-out lower mudguard fixing (which projects inwards just a little) into contact with the bolts on the disc brake attachment on the wheel. Which explained the partial rotation and the mechanical blocking. I don't have disc brakes, so simply taking the bolts out should have fixed the problem. Certainly the wheel runs smoothly now ...........
But it still doesn't work - display lights up showing full, but with an odd red ?fault light. Looks like an empty battery signal ... but that makes no sense.
I think this is a result of a separate, earlier, idiocy when I made some error in connections and I suspect fried the controller. So I will replace that and make no returns.
Unless anybody has other ideas?
I can only say "well done" as well as "not well done!"
Very pleased that you found the main problem, but sorry about the new one.
Have you checked everything is correctly connected? Have you made sure that the battery is charged?
I think personally that any serious e-biker needs a small tool set for bikers, plus a few other bits like Voltmeter (Digital multi-meter, very cheap!) and either a micrometer or a vernier gauge.
I recommend the latter as it can also measure internally in say a tube and has wider jaws and is usually cheaper.
Today digital ones (good enough for government work) can be bought cheaply online! They were all expensive when I was learning in the 1960s!
Best of luck, but you could (sadly) be right about the controller.....
Are the instructions you got good and easy to understand?
Maybe someone here has some ideas, but new controllers are cheap on ebay....starting at around 20 UK Pounds. Chinese quality.
Andy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
Don't replace anything until you test where the faults are. The tests are very easy to do and will identify which bits are faulty. You didn't answer whether you have a meter.