Mxus 3000 vs Cromotor?

I Wonder what is the totalstator effective surface area diff between the MXUS 3000 and the cromotor?

one is 45mm and the other is 50mm but what about the circuference?

wider stator mean more torque.. but diameter too!

wodl be great to have a neutral comparaison between both... ex with let say 20cm stator diameter and 50mm width this is 314mm sq of effective stator core surface facing the magnets rotor.

From what i remember it look like the MXUS 3000 is larger diameter right but have 5mm less stator width...?

so could be the MXUS similar total surface of stator the same as the cromotor ?

And is the torque proportional to the effective surface of the stator?

you see what i mean guys?
 
The MXUS motor stator diameter is the same size as their smaller motors. I believe all these diameters are based on the I.D. of an 8" iron pipe, which is the back-iron used on the rotor magnets.
 
they have almost the same spoke flange diameter (mxus a little smaller but thinner back iron) so stator diamter will be 99% the same.
 
That stator steel is a common generic part in China used on millions of hubmotors, so I'm pretty sure the OD of the stator is the same.

Adding some extra width to the stator decreases Kv for the same winding, so it increases the torque per amp, and while the copper is a very slightly longer it's still the same thickness on each turn, so it's capable of the same current levels. That makes it ultimately a higher torque motor. Controller settings and good tuning gets so little attention from the vast majority of members that the potential performance difference pales by comparison, so the real differences are those I mentioned in the previous post.
 
Btw IIRC there have been some talk about Cromotor v4 launching this spring.
Can anyone confirm that?

If there is such a thing as Cro v4 coming, what changes will there be? Any changes in weight, Kv or copper amount?

And if a v4 is coming when can we expect it to be out?
 
macribs, i have asked zelena vozila the same things two or three times but they never give me an answer. since this i will not come to them again.

and since the manufacturer QS offers the motors also with axle for 150mm bicycle, i see no reason for spending some extra dollars for a "real" cromotor.
AFAIK they even offer them with more copper fill (the "extra type") and different turn counts
 
madin88 said:
AFAIK they even offer them with more copper fill (the "extra type") and different turn counts
Click to expand...

maybe this is or will be the v4 cro?
Litte bit more max efficiency, little more torque....

Its obvious why they dont talk about the benefits for getting a "real" cro.......maybe they order them from qs and thats it.

It makes no sense to keep this "improvements" of the so called "real" cromotor a secret.

When i sell a product which is better than another.......why not promoting these better features?
 
macribs said:
So should we try to do a group by of the cromotor directly from QS via the QS thread in for sale section?
If we could order at least 10 maybe we can get price down too, and get the motor with extra fill?
Click to expand...


Great idea.

Doc
 
As I am in Norway and we are outside the EU. So that means the custom fee, taxes, VAT and duty for these motor would add significant costs if I where to host a group buy and have the lot send here.
So I can't host a group buy - all I can do is join in on one.

Wonder if any US or EU es member can take on the task to manage a group buy - as I think there will be less taxes, custom fees and VAT if we do it that way. And cheap bargain prices is what we are after, right?

Btw. How is Canada on taxing Chinese goods these days?
 
In for group buy. Need soon!! Do you think we could order any different windings on this new version? I really need (want haha) around 10-10.5kV.
 
routy, the kV you want will not be possible with this motor. the options with QS 205 / 50 (Cromotor) should be 9,3kV (4turn) or 12,37 (3turn)
 
The two version of cromotor are really similar to the old X5303 and X5304 in term of Kv and these X5 motor was the most popular too.

5303:

-winding:
--Kv: 12.1
--turns: 3
--number of strands: 8
--size of each strands: AWG 20 ( 0.033"dia)
--All strands = to one AWG 11 conductor
--inductance between two phase wire: 169uH with my meterman XR37 and 220uH(retested with calibrated Agilent LCR meter) 5 jan 2014
--DC resistance between two phase wire:0.097ohm(direct to winding) and 0.103ohm(thru the anderson connector)

-number of pole: 12
-number of magnets: 24
-Stator/magnets width: 32mm



5304:

-winding:
--Kv: 9.1
--turns: 4
--number of strands: 5
--size of each strands:
--All strands = to one AWG
--inductance between two phase wire:
--DC resistance between two phase wire:

-number of pole: 12
-number of magnets: 24
-Stator/magnets width: 32mm
 
Drunkskunk said:
I'm interested in figuring out how these compare to the bigger 5403 and 5404 with their 42mm stators.
Click to expand...


IIRC those 5xxx has had trouble with axle and also heat up more then cro. This is from memory, I think is it several threads here that claims problem with the 5xxx. Also smaller stator = less torque compared to Cro's 50mm. And less torque for me translates to less acceleration.
 
I have confirmed via inspection and testing on the MXUS 3000W Motors as follows:

21X3T Winding:
12.02 Kv
0.796 Kt (Nm/A)
0.072 Ohms resistance (Measured from end of base phase wire, (~1 meter Lead to Motor axle)
Weight (Bare Hub Motor): 9.0 Kg
Km (per Miles' Database Formula): 2.965

16X4T Winding:
8.9 Kv
1.073 Kt (Nm/A)
0.112 Ohms resistance (Measured from end of base phase wire, (~1 meter Lead to Motor axle)
Weight (Bare Hub Motor): 9.0 Kg
Km (per Miles' Database Formula): 3.206

12X5T Winding:
7.2 Kv
1.335 Kt (Nm/A)
0.170 Ohms resistance (Measured from end of base phase wire, (~1 meter Lead to Motor axle)
Weight (Bare Hub Motor): 9.0 Kg
Km (per Miles' Database Formula): 3.239

On the 3T Winding which I upgraded the Phase Wires, I have the following:

21X3T Winding:
12.02 Kv
0.796 Kt (Nm/A)
0.060 Ohms resistance (Measured from end of base phase wire, (~0.5 meter Lead to Motor axle)
Weight (Bare Hub Motor): 9.0 Kg
Km (per Miles' Database Formula): 3.248
 
What I have been able to dig up online regarding the Cromotor: (If anyone wants to test their Cromotor (Bare Hub) and post results, that would be appreciated.)

18X4T Winding:
9.3 Kv
1.027 Kt (Nm/A)
0.085 Ohms resistance (Measured from end of base phase wire, (~0.5 meter Lead to Motor axle)
Weight (Bare Hub Motor): 11.0 Kg
Km (per Miles' Database Formula): 3.521
 
Awsome work!

The phase wire resistance add important change to the evaluation.. but we should not forget that this phase wire additional resistance will create heat OUTSIDE of the motor so it cool faster and wont make the motor to heat more

Would be best to be able to get the Ohms resistance (between phase) directly on the winding and not from the wire lead. This would isolate the heat produced only Inside the motor witch really matter.

In fact it is pretty simple to get a acurate measurement of that with a 4 wire kelvin method for resistance measurement. connect the current source to the end of the phase wire lead and measure voltage across the winding junction to the wire Inside the motor.. but as well this require to open the motor.

The phase wire lead false the result for the REAL resistance of the motor witch should be only from the current path of the Inside of the motor witch is the heat production that matter...

Even if you could it wold be very nice to measure the WINDING ONLY resistance :wink:

I believe it's a matter of generated heat Inside the motor and a parameter that determine the max power vs time we can use that motor at.
This would isolate the real parameter that would become independent to the phase wire upgrade we make.

Doc

Doc
 
Official results are in for the 4T MXUS 3000W Hub Motor.
It's also now on the simulator as "MXUS 4504_V2"

Justin-le said:
the measured peak efficiency of the 4T motor at both 36V and 48V was right around 90%, and the no-load losses were about 2-3 times lower than say the similar sized Crysatlyte Crown motor. So really quite an impressive electrical performance spec, and the same lamination material in a normal 25-30mm wide motor would have one of the lowest cogging drags of any direct drive hub out there.
I've put this model up on the simulator and have put the test result graph inline here, and should be able to get to the remaining hubs by the end of the week.
Click to expand...

8)
 
thanks for the good news teslanv. now its proven the MXUS V2 is a very good motor :)

it would be great to also have QS V2 and V3 in the simulator. i very would appreciate this if you could also manage this. if you start crowdfunding im definitely in!

btw: how does justin calculate the "time before overheat"? is it based on motor mass?
 
I find this interesting because I thought the cromotor hands down was much better than the Mxus 3000. Well, at least a lot more than 10% better.

8.3kg vs 11 kg

So are you saying that the cromotor v3 is only about 10% better while being over 30% heavier in weight? Better here means in overall performance, however you want to measure that.
 
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