Poor Torque on a 1000w Gearless Hub Motor!

bobsyleck

bobsyleck

1 W
Joined
Mar 22, 2016
Messages
61
Location
Cheshire, England
I'm having very low torque issues with my 1000W 48V Rear Hub Motor (Kit), also it does not like moving off from a standing start (in fact sometimes/occasionally refuses), the motor is loud and juddery esp. attacking an incline, however once up to speed all is sweet!!
I have the Tester Unit (Lyen omnitester) which is telling me that hall sensors, phase wires, throttle etc. are all OK !! so I'm putting it down to either a blown MOSFET? - which I'm not sure I can test without removing? Or, it could be that my Lead Acid Batteries (new) aren't providing enough Amps for the initial take-off? (they're only 10Ahr each x4 in series)?
I added a third shunt as there was an empty space available (2 shunts already insitu), and I swapped out the 63v capacitors for some equivalent but better spec (100V, same 470uf) *Nichicon FW Series Audio Grade Electrolytic Capacitors 100V
I've used 10 gauge (6mm) wiring on my rig apart from where the final battery connects to the Controller, as the Controller feed wires are somewhat less capable than this (its just the way they come).
I'm looking for someone with more wisdom than I on these matters! I'd hoped to have solved any poor amperage issues with good caps 'n shunts and superior wiring (up to a point) but think maybe the Pb battery specs are simply not up to it? Or as I said earlier, perhaps a defunct MOSFET? (any one of twelve!!) :roll:
 
Did you test your setup before modifications to the controller? You may have installed a part thats hurting your performance.

As a rule I peddle from a dead stop and get rolling at least a couple mph before I hit the throttle and keep peddling up to at least 10mph. I also have a 1kw brushless gearless 48v rig. Torque is not very good on the low end but if I give it a little help the acceleration is impressive. Going up medium sized hills is no problem above 10mph but my motor isn't wound for slow speed performance and performs best at higher rpm. So if I get a running start it doesn't struggle too hard. My top speed is about 30mph.

Your SLA batteries are more than capable of providing around 20-30 amps your controller requires from a start. They're used in jumper packs for cars because they can put out a lot of amps for a short amount of time. IE: lots of amps from a dead stop. Charge voltage is important though. Even my high discharge lipo batteries get sluggish under a half charge.
 
yeah, thats kinda what happens with me - once I have momentum the motor can get up to good speed and goes much quieter, as if less stressed! Just as long as i start off with a few rotations of the pedal; If this is normal then all's OK.
I used to have a Geared 250W rear Motor which was ever so quiet and smooth even from a standing start!! but on the other hand it never achieved any significant speed.
I guess trying to compare the two 'operationally wise' was the wrong thing to do?!
If giving the 1000W Motor a little pedal aid to begin with is a normal situation then I'm happy to live with it - after all the top speed is impressive and the juddering noisy episode disappears when motoring along :D
 
That sounds about right. We might have the same motor. I'm happy getting my legs moving a bit to get up to speed then I cruise along around 15-25mph. But I couldn't help myself and ordered a 1500 watt setup and more batteries to get to 66ish volts. I find it amusing when I hit the throttle and can pass a car with my tricycle.
 
lol, perhaps a GoPro on yer helmet and a glance at the Driver's face as you pass would be a good one for the album?!!!
d'ya think these Motors 'settle-in' a little with usage? mine's right out the box last week so perhaps the noise 'n stuff will dissipate somewhat as it gets used!! Not sure if that's true?
If a little pedal assist and momentum is the norm for these larger motors to perform their best then that's an acceptable sacrifice to make given the way it can eat-up those long straights :D :D :twisted:
 
Brushless motors do not break in like a traditional brushed motor. The bearings do not need to break in either. The motors growl and are noisey due to cheap controllers. Read up on some wave controllers for more info. A sine wave controller is much quieter
 
Thank you 'CaliClouds', I'll do just that. This chinese controller that came with the kit 'looks' big 'n impressive but i guess quality rarely comes cheap!
As you say, perhaps a Sine Wave Controller would suit my needs better or at least a good 'Named' Brand one (this one is indeed 'nameless'!)
 
It sounds like an incorrect hall/phase wiring combo. If so, then it's a false positive in the right direction, so swap 2 and only 2 hall wires, and then find the right combination of phase wires of the remaining 5 possible. Use small throttle pulses. You do this with the wheel off the ground and chain off, so the pedals don't whack you with a fast reverse. Consider yourself lucky to not have done damage from overheating with a bad wiring combo, which results in low torque and high current.

Beforehand check the no-load current, which will be relatively high with a wrong combo. Valid wiring should be low current at WOT with no load. Poor torque and noisy startup are symptoms of a false positive wiring config.
 
Well thats a suggestion for resolving my issue I'd never heard of, you might well be right-on track with that?!
Thank you most kindly for the heads-up.
With my old e-bike (the 250W one) I noticed when it first arrived that to get it working i had to change over the phase wires i.e. Green went into Blue (or something like that), and that got the motor running. problem solved - was easy.

Are there any directions on YouTube, or any forum, which shows a work through for employing that technique you suggest above?
Again, very much appreciated

With the wheel off the ground and 'Load Free' (i.e. bicycle Inverted) the response when using the throttle appears 'perfectly' normal - the wheel is quiet and responsive!!! **Don't know if this info helps?
p.s. If my e-bike is working perfectly normal i.e. smooth quiet and responsive, when the bike is inverted and therefore the wheel/motor is under no load whatsoever, how can I test whether I have the right combo of Phase/Hall wires? because the proof of the pudding will only reveal itself when 'underload' and I'm setting off on my journey, fully laiden!! - thats the only time I get juddering and noise and very poor power.
 
https://endless-sphere.com/w/index.php/Determining_the_Wiring_for_a_Brushless_Motor
 
My guess is incorrect combo, or just bad connection on one phase. Particularly a bad connection on a big wire. It may be running 1000w,1000w, 100w, 1000w, 1000w, 100w. So the end result is it turns, but has 2/3 power, and if it happens to be on the poor phase, it won't even start.
 
Thank you for the input.
well I did as 'John in CR' suggested previously i.e. swapped a couple of hall sensor wires over and then tried different phase combos, which resulted in a backwards motor etc. (as he said it might), and the throttle response did engage from standstill every time, so things initially looked positive & suggested I might be on the right track, but the Motor sounded a bit louder than it did previously (when not under any load!!), & not as smooth, + I noticed a definite heat build-up in the controller wiring, which has worried me enough to revert back to the original set-up.
Although I may have power issues starting from standstill (and a noisy motor) all this goes away after I gain momentum so it's not all bad; i was expecting an ultra quiet Motor as I'd heard these gearless hubs are supposed to be the quietest?! - I expected it to be quieter than my previous 250W geared Motor, which was perhaps too optimistic.

I'm putting my options down to three:
A) get some decent wiring on the Battery to Controller input - as this might be a weak point & choking the Amps
B) invest in a good 'Branded' Controller and ditch this cheap one that came with the 'bargain' Chinese Kit. *Maybe one with the self-Learning capability/connection
c) Just Live with it, it ain't such a big deal :D

p.s. I did check Hall sensors, Phase, Throttle etc. with the little white box of tricks the Chinese sell http://www.ebay.co.uk/itm/24V-36V-48V-60V-Car-E-bike-Scooter-Brushless-Motor-Controller-Tester-24V-to-60V-/261882557737?hash=item3cf96ab529:g:eek:qMAAOSwNSxVTrcJ and everything checked-out OK; all the little red LED combinations delivered as expected on a healthy set-up.
 
bobsyleck said:
Well thats a suggestion for resolving my issue I'd never heard of, you might well be right-on track with that?!
Thank you most kindly for the heads-up.
With my old e-bike (the 250W one) I noticed when it first arrived that to get it working i had to change over the phase wires i.e. Green went into Blue (or something like that), and that got the motor running. problem solved - was easy.

Are there any directions on YouTube, or any forum, which shows a work through for employing that technique you suggest above?
Again, very much appreciated

With the wheel off the ground and 'Load Free' (i.e. bicycle Inverted) the response when using the throttle appears 'perfectly' normal - the wheel is quiet and responsive!!! **Don't know if this info helps?
p.s. If my e-bike is working perfectly normal i.e. smooth quiet and responsive, when the bike is inverted and therefore the wheel/motor is under no load whatsoever, how can I test whether I have the right combo of Phase/Hall wires? because the proof of the pudding will only reveal itself when 'underload' and I'm setting off on my journey, fully laiden!! - thats the only time I get juddering and noise and very poor power.
Click to expand...

With no load it's not so much how it runs, though higher than expected no-load top speed is another indicator of incorrect wiring combo because a "false positive" is a IME a very advanced timing. They can be tricky. The telltale signs of a false positive are:
1. How smoothly it starts to spin when you apply the small throttle pulse.
2. High no load current at WOT (Wide Open Throttle).

If yours is a Sensored/Sensorless controller that can add to the confusion, because a bad hall combo can kick it into sensorless operation which IME has the symptoms you mention... more rattletrap startup and the inability to go to full torque.

Since the firing sequence of Yellow/Green/Blue is not standardized among manufacturers, I never trust color on color wiring, so I always try the 6 possible phase wire combos to make sure the smoothest sounding start no-load is the one I try for the first ride. I also always measure noload current before that first ride.

I could figure out wiring blindfolded, so I find the flow chart thing a bit silly, since by the time someone reads through the first try I will have already found the right configuration. If someone directs you to the 36 combo spreadsheet then ignore their advice, because that ridiculousness has caused many members countless hours of wasted time and frustration. Wiring config of a 3 phase motor is a simple math/logic problem. Every hall combo as one valid phase combo of the 6 possible, and every phase combo has one valid hall combo of the 6 possible. Of the resulting 6 valid combinations, 3 are forward rotation and 3 are reverse. If you get a reverse, just swap any 2 you were keeping static. Once you accept those 3 statements you never have to ask about or look up wiring configurations, because it's quicker to just figure it out yourself.
 
There's only one correct phase sequence. It's a 3 phase motor system. It can fire 1 2 3 or 1 3 2. That's it. Just change one set of wires. Either the halls or the phase wires, whichever is easiest to do for you. There's no need to change both. Each hall sensor controls the firing of one of the phases.
 
Ok People, i don't know if anyone's still looking in on this? but,
*update, i thought I'd try swapping the Phase wires around whilst under load (I was out shopping) and this is what i got:
first scenario was the motor went Backwards,
second scenario nothing happened,
third scenario motor sounded like it was spinning but it wasn't !!! * as if internally it was actually spinning!!

so now i'm really flummoxed
runs like a bag 'o nails from start off still & only seems to function properly on a flat and at good speed i.e. once the momentum is up. :x

btw thanx Wesnewell

Could I actually have a MOSFET issue? - given that my Tester http://www.ebay.co.uk/itm/24V-36V-48V-60V-Car-E-bike-Scooter-Brushless-Motor-Controller-Tester-24V-to-60V-/261882557737?hash=item3cf96ab529:g:eek:qMAAOSwNSxVTrcJ says all's OK with the connections!?
 
Did you go to the provided link, read it, and perform the exact steps?
 
What 1000W kit did you buy? They are not all the same. Some have a really fast kv, doing over 700rpm on 48V. These motors are only suited for small wheels imo. More typical are motors of under 10kv, or under 500rpm n 48V. If you've got a fast wind motor, you'll have to give it plenty of amps to get much power from it in a 26" wheel. It's really not suited for anything but a light rider on level ground that wants max speed imo. You can buy a timing light and test the unloaded rpm for about $10. That's what I did to test my motors.
http://www.ebay.com/itm/Digital-Laser-Photo-Tachometer-Non-Contact-RPM-Tach-Meter-Motor-Speed-Gauge-DI-/172118526442
I found my 1000W motor to be 9.75kv and my 3000W motor to be ~9kv. I'm suspecting you have a motor that's well over 12kv. You could try a shunt mod to increase the max amps of your controller and get more power for take off. I wouldn't go much over a 50% increase.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=31643
 
I'll purchase that strobe Wesnewell (its a good price); I'll try anything at present - I'm even gonna whip out the Mosfets now (reluctantly) and test them with this http://www.ebay.co.uk/itm/Transistor-Detector-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-UK-/391184294360?hash=item5b1466a1d8:g:gIcAAOSwstxVJiF7 which I happen to possess.
I've already suspected a shortage of Amperage for the size of Motor so I beefed-up the traces with wire and solder, installed Caps with better specs, added another Shunt (making that 3 now) but it's made no difference.

* there is something here that I did neglect to mention when initially Posting - when I very first hooked-up the kit a Switch I'd installed for 'Power On' (since been replaced) failed, causing the original two Main Caps to blow (lotsa smoke) and the shunt insitu appeared to act as a fuse and 'melt' breaking the circuit - possibly saving the whole Controller?!! However after replacing the Caps and Shunt and modding (as forementioned) the Controller 'appeared to be functioning again!
Thats why despite my Tester telling me Halls, Phase Wires etc, etc, are giving off healthy signals, that I may have damaged a MOSFET? But I don't know what the symptoms are if such a thing has occurred?

This was the original Kit http://www.ebay.co.uk/itm/181237508447?_trksid=p2057872.m2749.l2649&var=480281872482&ssPageName=STRK%3AMEBIDX%3AIT *1000W 48V version, rear wheel Gearless Hub
 
bobsyleck said:
I'll try anything at present
Click to expand...
How about trying the linked article?

While it is always possible there is damage in the controller, until you establish for certain that the phase combination is correct, everything else may just be a waste of time. ;)
 
Just spotted that link 'amberwolf', will get into that in a min :D :D ty

what a useful little diagram that was - did all that and I'm pretty sure that my original color coded Phase and Hall wire combos are the best suited - so no joy there. at least it clears that up :)
Used my Chinese Tester again too and it tells me yet again that all is good with throttle and Motor connections (as before).

I'm now beginning to suspect that this motor is purely designed for warp speed, using a bloody big battery, so if you fancy taking a shortcut down the M6 Motorway (or a German Autobahn) then this is the kit you need, but if you're only using a 10ahr Lead Acid and as you turn out of your driveway you are faced with an incline? or you're loaded with shopping and need quick acceleration?! then it's probably not the one to plump for.

just for peice of mind I'm now gonna pull all the Mosfets and test them one by one - it seems 'Wesnewell' could be right about the kind of application this highly wound Motor is suited for?! its not for plodding along. Perhaps a 500W woulda been better for me? The only reason I picked this was that my Brother had sourced me a 50V 50A (max) Lithium Battery but that unfortunately never came to fruition, and I'd already purchased the Motor on the premise he'd deliver.
Still, I suppose from time to time it'll cast me back to my youth, eye's watering, teeth full of flies and a change of underwear following a spell on some muddy/wet roads! *That's when the roads are pretty flat that is.

Thank you all, what a great bunch and what a great forum. If I do discover a dodgy MOSFET then I'll be sure to update this post. It may after all just be a damaged Controller? Or perhaps it truly is more akin to a highly tuned Rally Car - requiring a lot more umph than i can provide it with!? (at present)
 
As I understand all type of winds of the same motor can give the same torque (correct me if I'm wrong). So maybe you could get an other controller that can give more amps and/or add another 12V battery to your bike. But then you'll have to change the caps in your controller to 100V types as 5x 12V lead acid batteries fully charged will be more than 65V. You can also lace your motor in a smaller 20" wheel that way gearing it down.
 
Gotcha Slowco. I already have 100V Caps insitu (replaced the originals) - I may be looking at other more suitable controllers in the long run :)

**Nichicon FW Series Audio Grade Electrolytic Capacitors 100V 470uf
 
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