QS 3000w midmotor

[larsb]

There was a video linked, showing this motor at 30S or thereabouts. Would give 9000rpm or so with FW
Highly unsecure info though, wonder what the heating is like at those rpms.

With 5 pole pairs it could still be possible considering the lower erpm compared to most motors.

 

[PITMIX]

this video is awesome :
https://youtu.be/cgoqntM-P9g

 

[Maarkmo]

Can someone tell me what the inner pulley diameter is? Or the Shaft diameter? Qs motors doesnt have any available right now with motorcycle shaft they only have them ready with the regular pulley, im wondering if i can find a sprocket that i can fit on there.

 

[PITMIX]

Return to see on the previous pages (page 11) I put photos with all the dimensions.

 

[Maarkmo]

Return to see on the previous pages (page 11) I put photos with all the dimensions.

Oh wow you did all the hard work for me. Thank you! The measurements seem to be a little different each time you took it, but you said that the inner dimension of the pulley was 25mm is that correct? If this is the case then a sprocket with a 1 inch bore should be compatible with the shaft on that motor.

 

[PITMIX]

Please note the bore is tapered. 25 mm is for the flange seal

 

[Maarkmo]

Yes I'm aware. I think a 1 inch bore will work ill let u know

 

[PITMIX]

New Mid drive 4kW Qs motor 90H

https://www.qsmotor.com/product/4000w-mid-drive-motor/

 

[j bjork]

Yes, it is very odd that they don't have the same motors on that site as they have on http://www.cnqsmotor.com/en/article_list/Mid%20Drive%20Motor/107.html

 

[Schlafmutze]

One thing I notice with a lot of the QS mid drive motors are how heavy they are.
The power to weight doesn't seem to be a lot better than the hub motors.

 

[Merlin]

depends on your pov.

rated at 3kw, pushing 10 times the rated wattage doenst sound bad to me.

i think also controller is mostly the limit.

my small 1200w rated senli eats 22kw peaks. thats nearly 20 times of the rated power.

3kw hub motors aka qs v3 work without any heatfins or magnet eating ferrofluid inside 12-15kw "only" + some more kg weight.

 

[DanGT86]

Slightly OT but does ferrofluid eat magnets?

Also, this new 4k motor is listed at 13kg. Isn't that the same as the 3k? Can we just assume its 33% more capable?

They are saying its 14kw max and sometimes 20kw. All of that sounds like what people regularly do with the 3k. 138 motor.

Is this maybe the 3k 138 motor with a slightly better design or is it bigger overall?

 

[j bjork]

I can also confirm how much more capable the 138 70h is compared to the 205 50h hub. When pushing about 24kw peak in both, the 205 overheats in maybe 15-20min riding in the woods. That is with statoraid and hubsinks. I have yet to overheat the 138 70h on a bike twice as heavy and twice as heavy terrain.

 

[larsb]

I don’t know anyone that smoked one yet
That’s a challenge for y’all

 

[PITMIX]

On 4kw Magnets are 90mm and 70mm on the 3kW

 

[DanGT86]

All things being equal that would mean more torque per amp right?

 

[Merlin]

QS 4000 mid will power a Quantya next weeks. ASI 8000, 5.8kwh 20s battery.

lets see if we can reach 40kw

 

[PITMIX]

7000rpm vs 6000rpm, 70Nm vs 56Nm all is stronger !

 

[DanGT86]

Thats all good news. Now we just need A super thermo nucular controller.

 

[markz]

7000rpm vs 6000rpm, 70Nm vs 56Nm all is stronger !

More power and torque the better!

IMHO

 

[PITMIX]

More power and torque the better!

IMHO

Exactly

 

[TorgueRPM]

I just got my motor today, a v2 3000w version. I spun it up on my ASI BAC4000 on sensorless mode and it makes this weird noise, definitely not what I'd expect with FOC or sine wave. I haven't noticed this noise in any other videos. I also noticed a similar noise when I spun the motor up with a drill, disconnected from the controller, and when spinning it by hand. There is no noticeable resistance when turning it though. Any ideas as to what this might be?

https://youtu.be/KeXE-3S6kVo

 

[larsb]

probably bearings damaged during assembly.
second guess is that sensor ring is touching something. remove cover on the rear side to check this.

 

[flippy]

i see some version with chain drive and others with belt. does QS supply a belt option and what belt model does it have?

 

[larsb]

it's HTD-8M-20mm (or the nicer GT variants) but the rear pulley they use is not cut to more than HTD standard.