MXUS 3000 Hub Motor - V1 V2 V3

[sacko]

Can anyone who has their motors, or even laced them; confirm these are the correct measurements.

Looking for the correct specs for "Hub Flange Diameter" and the "Flange Spacing" numbers for calculating spoke length. Believe its Hub Flange Diameter: 231 mm; Flange Spacing: 49.5 mm; Diameter of a Spokehole: 3 mm. For the USA Group Buy for MXUS 3000W Hub Motor which I signed onto. Also, motor centers on the rim, so no dishing, right? Thanks.

I'm currently looking at ordering these sized spokes for the JRH 19" Moto rims.

 

[Emmett]

Sounds like this motor will have some serious top speed potential. How efficient might this V2 motor be when used in low speed high torque riding conditions? Compared to say a H4040. That is riding at 5 to 35 km/h, and needing very high torque for 10 to 15 minute periods of hill climbing on trails. I suppose the ability to modulate the torque smoothly with the throttle is dependent upon the controller smarts, right? Torque control is important to me too.

 

[teklektik]

I will be doing independent Kv tests on those winds as soon as I receive the motors (within 2 weeks) and will confirm the Kv.

Outstanding. Looking forward to the results.
Thanks!

 

[madin88]

Sounds like this motor will have some serious top speed potential. How efficient might this V2 motor be when used in low speed high torque riding conditions? Compared to say a H4040. That is riding at 5 to 35 km/h, and needing very high torque for 10 to 15 minute periods of hill climbing on trails. I suppose the ability to modulate the torque smoothly with the throttle is dependent upon the controller smarts, right? Torque control is important to me too.

its the same thing like with any other hub motor.
50% of unloaded speed results in about only 50% efficiency
torque = heat (no matter what turn count).

for your purpose it would be better to look for a middrive or build one with this motor with 1:2 gearing.
a very fast wind motor would be nice for such a setup to also have good top end speed -> is 30x2 turn possible?

 

[teslanv]

I has asked about a 20X3T winding, but MXUS said that was "Too dangerous"

 

[madin88]

I has asked about a 20X3T winding, but MXUS said that was "Too dangerous"

it would be interesting why exactly its to dangerous. sure it makes no sense with such small phase wires, but for the motor it should be no problem..

 

[John in CR]

I has asked about a 20X3T winding, but MXUS said that was "Too dangerous"

That's perfect example of what I talked about before with even manufacturers not really understanding motors. If that 4 turn Kv is accurate, then a 21 strand 3 turn is the one to not accept no for an answer. "Too dangerous" is ridiculous.

 

[e4bike.ru]

What will you do with the 3Tx21 motor with 13G phase wires? 4T is the lowest possible turn count for 13G phase wires, that is my opinion.

 

[John in CR]

50% of unloaded speed results in about only 50% efficiency
torque = heat (no matter what turn count).

This isn't accurate. 50% efficiency at 50% of no-load rpm only occurs when motors are pushed to their absolute peak power, ie full stator saturation. Other than maybe getting a few spin ups on a dyno, a hubmotor can't be used at those current levels without burning them up. That means we rely on current limiting to protect our motors, and it has the effect of broadening and flattening the power and efficiency curves. To get a good feel for those effects load up a speedy wind motor in the Ebikes.ca simulator and simulate with different controller current limits and see what happens as you restrict current. It's not too difficult to have settings that cross through 50% efficiency at below 20% of no-load.

Taking advantage of extreme current limiting for off road riding requires a large motor and gearing for a lower top speed than you'd use on the street. Look at Zero emotos as an example. They have a motor large enough that they can run it conservatively (lower than max current for a broad efficiency curve), and gear their dirt bike(s) to a lower top speed to meet the greater load demands and repetitive low speed high torque accelerations of off road riding.

 

[edventure]

Hi Teslanv,

Not sure if this has come up or not, but I am curious for my own future knowledge if you know or could ask what the temperature class of the magnet wire used in these MXUS motors is? There is such a range of coatings for magnet wire and am curious to know if they are just using the cheapest low quality 105C wire or something with a higher rating.

Thanks,

Ed

 

[e4bike.ru]

The Curie temperature is 120C as I know.

 

[edventure]

The Curie temperature is 120C as I know.

Thanks ebike.ru, I was figuring something in this range. I wish someone would make one with a higher temp insulation, "200 or 240". Ideally you don't want to run it that hot, but when you do long 20 mile runs like I do, having that added level of over engineering makes it less likely to have a problem.

Ed

 

[e4bike.ru]

Sorry, I thought you asked about Curie temperature of magnets. It is 120C. For the wires it is 150C working.

 

[John in CR]

What will you do with the 3Tx21 motor with 13G phase wires? 4T is the lowest possible turn count for 13G phase wires, that is my opinion.

I wouldn't use 13awg phase wires on either one. I take it that the strands used for winding are the typical 20awg stuff. 15 strands of that is the equivalent of between 8awg and 9awg, so why on earth would anyone want to use 13 gauge phase wires at 3 times greater resistance per unit of length than the copper wound on the stator? To maximize the copper size coming out of the motor I use magnet wire with all 3 phases, halls, and extra wires made into a single bundle to waste the least amount of cross-sectional area on plastic insulation, as well as get shape that better fits the shape of the exit. I've used this method with great success on 4 motors with about 15cm of magnet wire outside the axle, enough to do the drip loop and then attach individually insulated more flexible phase wires. In the future, I'll use small gauge magnet for the halls and sensor wire instead of the plastic covered stuff that wastes significant room and commonly has low temp insulation.

For custom ordered motors, I wouldn't have them attach phase wires at the factory. Instead, I'd have them leave each phase of the winding terminated normally at the ends. For the halls and other wires, just have them attach normally, but not run them out of the axle, just tie that bundle down inside the motor as well. The factory should love that...no cost in phase wires, and no potential for wire damage in shipment. It also allows me to get a much lower resistance connection of to the end of the windings, because I never like the way the factories attach the phase wires to the ends of the windings and always beef that up with extra copper anyway.

 

[e4bike.ru]

They use 0.5mm diameter wire for windings. It equals 0.2mm2 square. So having 4Tx16 we have 16*0.2=3.2mm2 square for windings. This is similar to 12AWG not 8-9. 13AWG for 4T motor is enough, our several rides feeding 250A phase current and 11kW total into 4Tx15 v1 motor in summer 30+C temperature proves, nothing melted. The motor had temperature control.

If you want 3T then we have 21 wires that equals to 21*0.2=4.2mm2. Having 13AWG phase is not good in this case. Also you will need some big connectors like XT150 to be sure they don't melt. Average phase current will increase for 3T motor for the same overall power.

MXUS makes ready-to-use motor and gives guarantee for it. That is why they don't recommend having 3T motor. If you remove guarantee they will wind 1Tx60 for you, no problem.

 

[flathill]

i know of a custom RC motor with 0,1mm lams and it was a bit more efficienct than the same motor with 0,2mm lams. if i remember right this motor was used in a pylon plane for speed / lap records.

Sure this leads to less iron because there is an "air gap" between every lam, but if it even was better for above purpose, going here from 0,5mm to 0,3mm will not have any disadvantages.

I am being pedantic but saying thinner lams will not have ANY disadvantages is not true. You can say probably overall no disadvantages or virtually zero disadvantages and that is OK. We don't even know what the lams are made of.

As the lams become thinner the iron fill factor decreases at at faster and faster rate since the insulation thickness is fixed. It is not linear. Add to this laminations are not perfect. The achievable stacking factor is not the same as the calculated stacking factor.

Skin effect eddy current losses related to thickness are only part of the story. The quality of the material matters just as much. Eddy current losses also depend on resistivity. Then you also have hysteretic loss that also depends on the material props. Stacking factor effects energy transfer (efficiency). I am not saying that thin lams are not needed for high frequency operation, but do you even know what frequency this direct drive hub motor is running at?

 

[John in CR]

They use 0.5mm diameter wire for windings. It equals 0.2mm2 square. So having 4Tx16 we have 16*0.2=3.2mm2 square for windings. This is similar to 12AWG not 8-9. 13AWG for 4T motor is enough, our several rides feeding 250A phase current and 11kW total into 4Tx15 v1 motor in summer 30+C temperature proves, nothing melted. The motor had temperature control.

If you want 3T then we have 21 wires that equals to 21*0.2=4.2mm2. Having 13AWG phase is not good in this case. Also you will need some big connectors like XT150 to be sure they don't melt. Average phase current will increase for 3T motor for the same overall power.

MXUS makes ready-to-use motor and gives guarantee for it. That is why they don't recommend having 3T motor. If you remove guarantee they will wind 1Tx60 for you, no problem.

.5mm diameter is about 24gauge. That's like the solid core wires in network wire, though I personally use 23awg network wire. I don't think I'm quite that blind yet, but the wire pictured on stators on earlier pages doesn't look like .5mm diameter, but instead like .5mm2 wire I've seen in almost every hubmotor I've opened. It's about the equivalent of 20ga. Sure the enamel on the wire adds some diameter, but not much.

Go ahead and run 13 gauge wire if you want, but that drastically increases the chances of blowing halls when the phase wires in close proximate to the halls get hot enough to weaken the hall wire insulation causing shorts and blowing halls. I believe this is the most common cause of blown halls, and why people just blow them again after replacement, because they didn't change the hall wires, which were the problem to begin with.

The 40mm motors I got back in 2008 had the channel type wire harness exit, and despite a huge amount of cross sectional area taken up by a rubber-like plastic, they still managed to fit the metric equivalent between 11 and 12 gauge phase wires. 13ga is fine to accept to get the lowest price, but I'd suggest that users upgrade that themselves.

The Chinese have no real understanding of how we run our motors, and while 13ga is marginally acceptable if running only the rated 3kw, it's not acceptable for what the buyers plan. As far as warranty, I've never made a warranty claim with any ebike part. I honor them myself, but that has all been shipment damage related.

 

[madin88]

This isn't accurate. 50% efficiency at 50% of no-load rpm only occurs when motors are pushed to their absolute peak power, ie full stator saturation.

if you take phase voltage (why should we use battery voltage?) for calculating no-load speed, than efficiency is somewhere in the range of 50 - 60% at 50% of no load RPM. NO mater what current.. :wink:
this is with any BLDC motor - isnt it?

@ flathill

of course you have right. please let me correct myself to "virtually zero disadvantages".
those RC motors with 0,1mm lams are running at very high ERPM (7 pole motors at past 20.000 rpm). good RC controller can do 250.000 or more. Thinner lams make much more sense there.

for this MXUS motor it mainly means we can run higher voltage with still having good peak efficiency. right?

 

[Motobikewheels]

Can anyone who has their motors, or even laced them; confirm these are the correct measurements.

Looking for the correct specs for "Hub Flange Diameter" and the "Flange Spacing" numbers for calculating spoke length. Believe its Hub Flange Diameter: 231 mm; Flange Spacing: 49.5 mm; Diameter of a Spokehole: 3 mm. For the USA Group Buy for MXUS 3000W Hub Motor which I signed onto. Also, motor centers on the rim, so no dishing, right? Thanks.

I'm currently looking at ordering these sized spokes for the JRH 19" Moto rims.

That look right!

 

[e4bike.ru]

I've never seen other than 0.5mm (0.2mm2) wires in popular hub motors. Quanshun motors (original Cromotor), all MXUS motors, Conhismotor they all have same 0.5mm wires. I'll take the photo when opening the motor next time. Such wire allows better copper fill and avoid skin effect.

Long time ago I rewinded a motor with 1mm wire. It was overheating like hell even having just a little less copper fill. After rewinding with 0.5mm the motor worked fine and still works.

 

[John in CR]

This isn't accurate. 50% efficiency at 50% of no-load rpm only occurs when motors are pushed to their absolute peak power, ie full stator saturation.

if you take phase voltage (why should we use battery voltage?) for calculating no-load speed, than efficiency is somewhere in the range of 50 - 60% at 50% of no load RPM. NO mater what current.. :wink:
this is with any BLDC motor - isnt it?

It's voltage that doesn't really matter, but current is what matters. Peak power, as in the maximum power the motor can produce at that voltage, occurs at 50% of no-load rpm and where efficiency is at 50%. If you increase current past that point then you would create more additional heat but no additional torque because the stator is fully saturated, so efficiency would be less than 50%. This is all readily visible using Justin's simulator and varying controller current to see the benefits of current limiting.

Peak efficiency otoh occurs with a light load at the point where copper losses = iron losses for that voltage. FWIW no-load current is important to us, because copper losses are low enough to be ignored if current is low, so it gives us a view of iron losses. Once no-load current starts getting high, then you're getting into the practical rpm limits of the motor, because you have the heat from the iron losses and other parasitic losses to dissipate on top of copper losses as you start adding load which demands more current. Copper losses increase by the square of current, so it becomes quickly apparent why current should be limited a phase currents tightly controlled (the motor only sees phase current) instead of the widespread myth of using a phase/battery current limit ratio of 2.5:1. This results in almost 3 times as much heat in the windings during the early part of acceleration than the 1.4-1.5:1 ratio I typically use, and when I push toward the limits of motor and controller I lower the ratio even more.

 

[John in CR]

I've never seen other than 0.5mm (0.2mm2) wires in popular hub motors. Quanshun motors (original Cromotor), all MXUS motors, Conhismotor they all have same 0.5mm wires. I'll take the photo when opening the motor next time. Such wire allows better copper fill and avoid skin effect.

Long time ago I rewinded a motor with 1mm wire. It was overheating like hell even having just a little less copper fill. After rewinding with 0.5mm the motor worked fine and still works.

I took a look at one of my older motors, and I stand corrected, because it has .5mm diameter copper on the windings. I had forgotten how little copper is on these common hubbies. I'd still bring thicker wire out of the motor though, since more will easily fit, and the 3 turn version with a thicker bundle coming off the windings. I doubt the size used has anything to do with skin effect though, since at the common 16khz operating frequency of our controllers, the skin effect is 0 up to a wire gauge of 17awg. It probably has more to do with what's easier for them to work with to achieve a nice neat wind.

 

[Relanium]

Chinese market realy is crazy....
Two different sellers

http://www.aliexpress.com/item/MXUS-45mm-magnets-high-powerful-motor/2043119619.html
http://www.aliexpress.com/item/High-Quality-E-bike-spoke-motor-3000W-Brushless-DC-Hub-Motor-for-Rear-Wheel-E-bike/2045060945.html

 

[Samd]

Yep, just ten bucks different. Not so crazy.Steel stators though. Still ok.

 

[MAGICPIE3FOCUSPOWER]

Thanks for your tip, but naahhhh v2 sounds better to me 8)