## QS 3000w midmotor

Electric Motors and Controllers
wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

Thanks for adjusting the quality level.
So it's easier for me to provide a positive contribution - I'll dare again
larsb wrote:
Nov 14 2019 3:54pm
Why not just google the field strength and conditions needed to demagnetize a neodym magnet.
Google'ing the coercivity of Nd Magnets yields somewhere between 600 and 1200 kA/m.
For Sa-Co I found values as low as 80 kA/m
larsb wrote:
Nov 14 2019 3:54pm
I bet it would take less time than writing the speculations.
Whats our field?
can still only speculate.
I remember a figure of some forty windings for a custom make, so 50 might be a reasonable order of magnitude.
People (larsb?) have reported 500 phase amps.
And we need some geometry factor (coil length?), for which I'd throw up 50 mm

200 A - 50 turns / 0,05m = 500 kA/m
So we are in the magnitude of Nd coercivity, and taking inhomogenous flux intoaccount, i still see a risk.

Loooks like I did'nt manage to shift the borderline of speculation that far
larsb wrote:
Nov 14 2019 3:54pm
I calculated the extra torque that this motor could give in field weakening because of the reluctance in IPM design, it was very small. I consider it as a normal bldc in this regard.
But as i've got it, reluctance torque and field weakening are different concepts?
Maybe both are utilized by the same sihft of current phase angle, but a motor w/o reluctance can still use field weakening - OK?

The rotor image here
viewtopic.php?f=30&t=93627#p1376479
shows nearly no gap between magnets, which I have learned were relevant for reluctance torque, OK?

Anyway, I'll not dig into all details of motor design.
I just would like to program my controller so that I can get out the torque curve QS labelled "with flux weakening" in their ads .
Unfortunately, the Votol controller figures are not comprehensible in terms of physical meaning - at least not for me.

QSMOTOR SPEC for VECTOR Dirt Bike V1.2.pdf
in this post
viewtopic.php?f=30&t=93627&start=175#p1461316
from QS Judy.

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

The figures you have are unrealistic. 50turns in a winding with 200A capability won’t be likely to happen in a motor size that is found here on ES. More like 10 turns 400A max

This paper is a good read, 100deg C, all d-axis current: https://www.researchgate.net/profile/Yu ... Curves.pdf
24ACA134-3141-4BB9-881B-365E689F1FA0.png (459.03 KiB) Viewed 2284 times
2% is lost in this example but at a really high temperature, 100 degrees in the magnets could damage them without outside field and the glue on surface mount magnets would be so soft that they might fly

Interesting that the d-axis is considered to be worst case as that is the field weakening axis so field weakening makes a difference, not only due to lower efficiency/higher temperature.
Ride on!

wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

so in essence:
There is a risk, but it can not considered separated from the thermal overload.
So, for practical use, it's still safe to play with settings as long as the motor des not go tooo hot.
OK?
And while playing with flux weakening params, it may be wise not to push heat to the edge, to avoid both stressors coming together.

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

Yes.

One might think that the field weakening parameters recommended in the Votol manual should be a good starting point for programming the Votol.
Ride on!

wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

Would be nice if we could relate those parameters to their physical meanings.
Educated guess is better than blind guess.
But I did not manage to understand them thus far.
I just see some dimsionless figures as input parameters into a black box, with some rough idea what might come out

Same with the phase current figure.
Well, for the last one, we may at least assume some proportionality with just the sacilng factor unknown, I suppose

There is a post from you
viewtopic.php?f=7&t=95969&p=1488169&hilit=flux#p1488169
with some quite larger figures than in the manual.
It shows a tzqs email in the corner. So we can consider them as authoritative and still safe?

Considering thread hygiene - should we shift this clarification to the Votol thread?

sleepy_tired   100 W

Posts: 101
Joined: Jul 02 2019 11:46am

### Re: QS 3000w midmotor

All I know about flux weakening is that experiences with SPM motors, especially DD hub motors, do not translate to IPM motors. Totally different beasts. Also that flux weakening may be necessary across the entire RPM range of a IPM to unlock the best performance.

The figures from QS are probably trustworthy and it would be a good idea to follow their specs and controller recommendations when just starting out. Once you get it going then you can work on unlocking the secrets. It's a pretty serious motorcycle/scooter motor and the hard part is going to be to something together that can handle it yet still be relatively light weight.

SilverLine   100 W

Posts: 110
Joined: Oct 09 2017 2:53pm
Location: Denmark

### Re: QS 3000w midmotor

So flux weakening compensation for this motor, is set to 64 pr. instruction from QS ?? (votol 150 and qs mid drive 3000)
And max 3000 for flux weakening value, for mid and high settings ??

wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

... and max 230 in the % fields?

180 A in the busbar current at Pg1 and 220 A in the boost aka sport current at pg2, if you want to retain warranty
(these figures are from the AliExpress Ad)
and 250 A if you'd risk warranty but still hope not to burn your equipment?

which times for sport mode logout and recovery?
30 / 30 s as in the vector specs?
and maybe less logout / more recovery if I try larger values in the other fields, to be on the safe side in terms of thermal safety margin?

And keep 9960 in phase current and stop thinking about how this translates to Amperes?

SilverLine   100 W

Posts: 110
Joined: Oct 09 2017 2:53pm
Location: Denmark

### Re: QS 3000w midmotor

I would like some screen shots from Larsb, showing
his page 1, 2 and 3

wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

#metoo

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

Ride on!

SilverLine   100 W

Posts: 110
Joined: Oct 09 2017 2:53pm
Location: Denmark

### Re: QS 3000w midmotor

larsb wrote:
Nov 22 2019 5:44am
And the other thread is about the controller and not motor. Come on...
They are sold together as a kit. Then there should be a dedicated "qs kit thread"

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

i can take a screenshot of the motor if you want

But seriously, all you need is in the votol thread already, read it and don’t be afraid to try it. You have wings, it’s time to fly
Ride on!

wjr   10 W

Posts: 69
Joined: Nov 08 2019 4:10pm

### Re: QS 3000w midmotor

larsb wrote:
Nov 22 2019 5:44am
Of course we are happy if you post it there
Or shall we repeat our plea over there?
larsb wrote:
Nov 22 2019 5:44am
Oh, yes, shots from so many people, and valuable comments from master @larsb

But I scanned the whole votol thread, and I fund just a half a Page2.
Flux weakening, valuable, indeed.
larsb wrote:
Nov 22 2019 5:44am
There’s no magic in the settings, only logic
OK, looks like Mr Professor wants to keep us struggling.
Never mind. Nobody can urge him to share his full knowledge.
Would I? I'm not sure.
Definitely not if I were in sth like a racing business...

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

What i am trying to tell you is that the emperor has no clothes..
I know nothing that can’t be read in the manual. Sorry! If you read it then you’ll know as much as i do.

Heck, you’ll probably even find things i never realised.
May the force be with you!
Ride on!

Stevebequik   1 mW

Posts: 15
Joined: Mar 18 2019 7:35pm

### Re: QS 3000w midmotor

Finally got my build up and running.
Full size KTM 250 exc, QS3000, Nucular 24f. 18s 3kw Chevy volt.
Recommend the new design, was able to bore the rear mount out to 16mm then mount it directly to the swing arm bolt. Perfect clearance of only 1mm away from the swing arm. Got the height right, then fabricated bracket for the front mount. Had motor installed in only several hours. New design also came with temp sensor installed(wasn’t requested) and 20mm 6 spline shaft for straight bolt on sprocket.
Something about this combo, sluggish off the line(500 phase amps). But really gets up and goes in the midrange. Can easily keep up with my friends on their 250’s. Current 11 front/60 rear will rocket thru to about 85kph with about 20kw peaks as the voltage rises.
Highest motor temp of about 62 degrees (tropical Australia summer f##ken hot) recorded on the Nuc controller.
Size, weight, functionality & efficiency of this controller is awesome. Just need to see if I can get the initial acceleration better. Vas needs to build a 36f with 750 phase amps.
Going to try a 10 front and a bit of field weakening to keep the same top speed.

efMX Trials Electric Freeride   100 kW

Posts: 1474
Joined: Feb 15 2013 4:43pm

### Re: QS 3000w midmotor

any pics, what chain pitch are you using?? sounds awesome:)
some ride & sk8 videos:
metacafe.com/channels/NATAS666DAMIEN
i have nothing for sale..

Stevebequik   1 mW

Posts: 15
Joined: Mar 18 2019 7:35pm

### Re: QS 3000w midmotor

Chain is a 520 x-ring.
Just installed the 10 front. Couple of pixs.
Still a work in progress.

SilverLine   100 W

Posts: 110
Joined: Oct 09 2017 2:53pm
Location: Denmark

### Re: QS 3000w midmotor

Just did my first test run, of the QS 3000 and votol-em150 controller. This motor got some torque....

j bjork   1 kW

Posts: 365
Joined: Aug 31 2018 3:01pm

### Re: QS 3000w midmotor

Stevebequik wrote:
Dec 02 2019 5:07pm
Finally got my build up and running.
Full size KTM 250 exc, QS3000, Nucular 24f. 18s 3kw Chevy volt.
Recommend the new design, was able to bore the rear mount out to 16mm then mount it directly to the swing arm bolt. Perfect clearance of only 1mm away from the swing arm. Got the height right, then fabricated bracket for the front mount. Had motor installed in only several hours. New design also came with temp sensor installed(wasn’t requested) and 20mm 6 spline shaft for straight bolt on sprocket.
Something about this combo, sluggish off the line(500 phase amps). But really gets up and goes in the midrange. Can easily keep up with my friends on their 250’s. Current 11 front/60 rear will rocket thru to about 85kph with about 20kw peaks as the voltage rises.
Highest motor temp of about 62 degrees (tropical Australia summer f##ken hot) recorded on the Nuc controller.
Size, weight, functionality & efficiency of this controller is awesome. Just need to see if I can get the initial acceleration better. Vas needs to build a 36f with 750 phase amps.
Going to try a 10 front and a bit of field weakening to keep the same top speed.
I am interested in what do you think when you have used it for a while?
I just bougt a KTM 200 exc without a motor, and I am thinking about what to use.
To be able to use QS3000 would be nice, but I am worried that it will be too weak?

minde28383   10 kW

Posts: 520
Joined: Apr 02 2010 7:11am

### Re: QS 3000w midmotor

Everybody will have different opinions about it. It will be a weak if you want to pull wheelies at 100km/h. It will be strong to spin wheel in low speeds if geared correctly. The lighter the bike the better performance.
Also take into account that it is not just motor which gives you good performance but controller and battery. So even if you install this motor it's performance depends on battery and controller to be used, and on gearing also.
If consider the money which this motor costs than there is almost no other options. It is light, small, and powerful motor.
Maybe you won't be using its full potential, because it can handle more than according manufacturer specs. Unless you install some other controller and powerful battery accordingly.
With low 8:1, 7:1 or 6:1 gearing you can have 250Nm-300Nm on rear wheel (depends on wheels diameter of course) and some 12kw - 17kw of electrical Kw. Can make it 20kw if have more money to spend to get more amps. So it's good 125cc and maybe some not powerful 250cc. So if you happy with considerably slow 125cc (fast enough, ~80km/h) than you should be happy with it's power. You can increase voltage if have option to do so and win some more power.
I will use it with 20S battery and stock controller.
ebike build in progress
CN 5.5kw scooter (on sale)
E Mindless Maverick Talisman longboard, 2.2KW motor, 150Amps controller (on sale)

j bjork   1 kW

Posts: 365
Joined: Aug 31 2018 3:01pm

### Re: QS 3000w midmotor

Thanks, I plan to use car battery modules. They are 12s, and difficult to split up (welded connections, cells might be glued together). So either I use them as 24s, and get a controller to match that. Like APT96600, or maybe 96800 or 961000 if I can find one.
Or if I am able to take the modules apart, I might make them 20-22s and use my nucular 24fet (500A phase, 300A battery) I don't know if that is enough, or how much more the motor can take? (I really like the nucular, but I guess it may not be enough for this bike)

As long as I use it in the woods, I would probably be fine with 75-80km/h top speed. If I register it for the road I will want higher top speed

larsb   100 kW

Posts: 1456
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

### Re: QS 3000w midmotor

get a votol em96300
you'll be first on ES with that
Ride on!

minde28383   10 kW

Posts: 520
Joined: Apr 02 2010 7:11am

### Re: QS 3000w midmotor

nucular 24fet (500A phase, 300A battery) is very enough, but up to 20s (90v). Maybe can be 21s, need to ask if is safe to go near top values on this controller, also it might depend if you use regen braking.

Regarding splitting modules or not. If you can accommodate unsplitted modules into frame and get 24s controller even better, more conventiant.

Both options are good just second one might be more powerful because bigger battery and more volts. Probably somewhat heavier and less compact if it plays any role.
ebike build in progress
CN 5.5kw scooter (on sale)
E Mindless Maverick Talisman longboard, 2.2KW motor, 150Amps controller (on sale)

Stevebequik   1 mW

Posts: 15
Joined: Mar 18 2019 7:35pm

### Re: QS 3000w midmotor

7C22DB7C-1B67-40EB-B33B-55F9A1096359.jpeg (137.09 KiB) Viewed 1050 times