MXUS 3000 Hub Motor - V1 V2 V3

[Hyena]

Does anyone knows what torque this motor has?

42

 

[999zip999]

The holes for the spokes is 7ga. Or 4.47 wow is this o.k. to lace to a bike rim ?

 

[Lyo]

My Revised Plan:

4T Wind, with the following Controller:

http://www.sabvoton.com/product/72v-6kw-brushless-motor-controller.html#.VF_Dz2d0yfA

http://endless-sphere.com/forums/viewtopic.php?f=30&t=62240

Sine Wave, Field Weakening, 350 Phase Amps, 6kW Continuous, 12kW Burst, Variable Regen. Best with 18S-20S LiPo.

Sorry noob question, what does "wind" mean? Is it like can you choose between multiple options?

 

[Lyo]

What controller and what voltage would you recommend me when I want to go 70 km/h with a 24/26 Rim?

 

[John in CR]

The holes for the spokes is 7ga. Or 4.47 wow is this o.k. to lace to a bike rim ?

A bicycle rim cannot withstand proper tensioning of motorcycle spokes.

 

[Motobikewheels]

The holes for the spokes is 7ga. Or 4.47 wow is this o.k. to lace to a bike rim ?

A bicycle rim cannot withstand proper tensioning of motorcycle spokes.

That's a pretty big hole! I will have mine tomorrow and check this out

 

[teslanv]

My Revised Plan:

4T Wind, with the following Controller:

http://www.sabvoton.com/product/72v-6kw-brushless-motor-controller.html#.VF_Dz2d0yfA

http://endless-sphere.com/forums/viewtopic.php?f=30&t=62240

Sine Wave, Field Weakening, 350 Phase Amps, 6kW Continuous, 12kW Burst, Variable Regen. Best with 18S-20S LiPo.

Sorry noob question, what does "wind" mean? Is it like can you choose between multiple options?

Covered in detail in this thread previously.
But basically it's kind of like a gear ratio for electric motors, except instead of using physical gears, it uses "winds" or "turns" of copper wire to provide a specific rpm at a given voltage, known as the "Constant of Velocity" or "Kv". The fewer the turns, the faster the motor will spin at a given voltage, and the higher the Kv.

For these 45mm Mxus motors, the common options are:

15X4 Turns (4-turn)
12X5 Turns (5-Turn)
10X6 Turns (6-Turn)

I have tested the different winds above and came up with the following data for the V1 motor:

15X4: 9.0 Kv (9 RPM per Volt) - (Comparable to the CLyte "High Speed" Motors)
12X5: 7.1875 Kv - (I believe the Standard Cromotor is also a 5-Turn Motor??? Can anyone confirm that?)
10X6: 6.02 Kv - (Comparable to the CLyte "High Torque" Motors)

 

[Lyo]

Ah alright thank you, I think I'm getting the "normal" wind version, from the european groupbuy

 

[teslanv]

Ah alright thank you, I think I'm getting the "normal" wind version, from the european groupbuy

The standard "normal" motor was the 4-turn "High-speed" wind.

 

[999zip999]

Yes roadrash please check it out and give some input. I"m worried.

 

[bataanjr]

18x4 Cromotor do so alone.

 

[Allex]

For these 45mm Mxus motors, the common options are:

15X4 Turns (4-turn)
12X5 Turns (5-Turn)
10X6 Turns (6-Turn)

I have tested the different winds above and came up with the following data for the V1 motor:

15X4: 9.0 Kv (9 RPM per Volt) - (Comparable to the CLyte "High Speed" Motors)
12X5: 7.1875 Kv - (I believe the Standard Cromotor is also a 5-Turn Motor??? Can anyone confirm that?)
10X6: 6.02 Kv - (Comparable to the CLyte "High Torque" Motors)

MXUS told me that they do:
16x4
12x5
More copper with the first option it seems.
Not sure wich one to take as John did not respond to Madins question

 

[teslanv]

MXUS told me that they do:
16x4
12x5
More copper with the first option it seems.
Not sure wich one to take as John did not respond to Madins question

More copper fill will mean better power handling. The 16X4 is the clear winner in the two examples above.

However, you need to consider what voltage of battery you intend to run, and how many battery & phase amps your controller supports, and what tire diameter you will ride, to make a good decisions about which option to choose.

The "How Fast will my bike be" equation (Simplified/generic concept):

Speed = Motor Winding (Kv) x Battery Voltage x Controller Current x Tire Diameter

Change one and everything else is affected.

 

[Allex]

24" 84V 150dc amps and 400 phase amps.
Torque is more important than speed in this case.

 

[teslanv]

24" 84V 150dc amps and 400 phase amps.
Torque is more important than speed in this case.

Assuming a KV of 9.0 for the 4-turn and 7.1875 for the 5-turn you would get the following unloaded speeds:

4t: 54 mph (86 kph)
5T: 43 mph (69 kph)

To calculate accurate No-load speed this is the actual equation:

Motor KV x battery voltage = Unloaded RPM

Unloaded Speed (mph) = Unloaded RPM x wheel diameter (inches) / 336


*However, with that much current you should get a significant speed boost and a TON of torque.

If you are running at 150A battery, that would be 12.6KW of power, which is more than e4bike used in the test video, and would likely overheat this motor in a hurry.

 

[Allex]

So wich one shoudl I choose for slow rides and steep hills? The one with more copper - 4t?
I will probably feed it with no more than 7-8kW - 100DC Amps tops because more than that will be to much for this little guy.
Thanks!

 

[teslanv]

For slow rides and steep hills, get the 5-turn or maybe even a 6-turn, and use a lower voltage, higher capacity battery that can feed a lot of current. Also, a "Slower" wind (5T or 6T) will reach it's peak efficiency at a slower speed than will a faster wind like the 4-turn motor.

 

[Allex]

Ok, 5T and 4t is in order for test. At the same DC amp and voltage, will the slower wind have better acceleration compared to 4t? thx again.

 

[wesnewell]

Unloaded speed @100V 4T motor
wheel dia times pi circum rpm MPH KPH
24 3.1416 75.3984 900 64.26 103.413618
26 3.1416 81.6816 900 69.615 112.0314195
28 3.1416 87.9648 900 74.97 120.649221

I'm putting mine in a 26" 4" fat tire that will have about a 28" wheel diameter. I'm kind of heavy so don't expect more than 60mph out of it with a 40A controller, but I really just want to be able and cruise at 40mph without over heating.

 

[Allex]

Well, you need about 4kw to hit 50mph So you will probably be getting around 40.

 

[Motobikewheels]

What is everyone using for spokes in these rather large holes? holes are 4.39mm

 

[John in CR]

More talk as if the Myth was true.

For goodness sake Wesnewell, use a smaller wheel. Why do you think there aren't electric motorcycles using hubmotors in big wheels? Reduce the 28 to 24" OD and you'll end up with the same or virtually the same top speed, you'll have better acceleration in the mid range, your motor will run at greater overall efficiency due to the lower gearing, and it will cool better due to the higher rpm.

150A battery 400A phase is a HORRIBLE setting. It might be okay with a sine wave controller if the only time 400A gets delivered is for a split second on launch and bemf reduces further it every step of the way as rpm decreases, but I don't know how they work. Didn't our Russian friend already experience a heat issues at much lower settings? Also, set the temp threshold conservatively, because at this price point I don't see it having the more expensive highest rated magnet wire, magnets, and epoxy. With common controllers no way is 150A/400A remotely close to reasonable settings. That kind of thing is a carryover from another myth only useful on direct drive hubbies below 1kw. Zombiess saw the light and settled on a 1.8:1 phase current to battery current limit ratio with 4 turn Cromotors, and I use a much lower ratio with higher speed wind motors so I can run higher battery current limits for greater performance in the mid range.

I feel that what I'm sharing is falling on deaf ears, but I want you guys to have success, because I believe in economical solutions. If my project list wasn't already overflowing I'd just clam up and order a 3x21 motor, put it in a 16" moto rim for a 21-22" OD wheel, put what I've learned about ventilation to work on this type of motor which I've yet to do, and lead by example. I'm doing a little moto conversion that should be a nice street performer, but it will be 2wd using a pair of very similar motors I've had collecting dust that are 2 turn with 40mm stators. They'll have 23-24" OD wheels in 17" moto rims, since I don't have any more 14's and these are already laced. It won't be a great comparison, but where I end up on controller settings could be useful, and if I go ventilated that definitely would, since I haven't put what I've learned in 2013 and 2014 about cooling to work on this type of motor yet. With these Mxus's so cheap it will probably be very interesting for guys thinking about 2wd with them though.

 

[teslanv]

John,
It sounds like you think a 3T (or whatever the "fastest" wind available is) is the preferred choice in every circumstance? Do I understand that correctly?
I understand that a 3T wind is better able to handle more phase amps than a slower wind, and that the amount of phase current a motor can handle before reaching saturation is directly related to the aggregate cross-dimensional area of the strands of copper making the circuit around each stator tooth.
Are there no circumstances where say you are limited to a larger tire diameter by design, that you would choose a "slower" wind motor for that specific application, provided it had the same total copper fill?

 

[douglashart]

I got my motor yesterday and first thing I noticed was the wires exiting the axel inside the dropouts. It appears to me that once tightened up, it will press the wires into the the casing that is revolving. All the schematics ive seen so far are apparently a later version, but they all show the wires exiting the end of the axel. The rubber cup appears to me to be for that version. im hoping to get some input on this before I fabricate my swingarm. A tiny washer would relieve the issue a bit just to space it off the wires. Sound like a good idea ??? Help thnx doug

 

[Kingfish]

Defining Speed – using mathematics

If we know the Power (P) and the Tire Size (given C, r, or d), theoretically we can calculate Speed (Linear Velocity, mph, kph).

• Mechanical Power (P) (kW) = (τ (Nm) * 2π * rpm)/60000
  ω = 2π * Revolutions per second (rps)
  τ = Force (F) * 2r
  Electrical Power (P) = Current (I) * Voltage (V)
  The motor constant (K) is determined by Torque (τ) divided by Angular velocity (ω).
  K = τ/ω
  Kv = RPM (rads/s)/Volt (V)
  Kt = Torque (t)/Amps (I)

Therefore Kv is relative to Tire Size. If we keep Power the same, Kv and Kt will change proportionally to the Tire Size.

In the ideal world, Kv and Kt are at inverse of each other: High Kv motors will have low Kt, and vice versa.

The highest efficiency the motor will display is during no-load at the highest possible battery voltage and current provided by the system, regardless of tire size – so long as it doesn’t overheat. It goes downhill from there.

• High Kv motors benefit from smaller tire sizes to improve their Kt.
• Conversely, high Kt motors will benefit from larger tire sizes to boost Kv.

Therefore, if desiring speed, higher-wind motors work best with larger tire sizes, and lower-wind motors work best with smaller tire sizes… Unless you have 2WD, where you can definitely use lower-wind motors on larger tires and still have an excellent torque experience at higher speed.

I just love it when it snows and I have winter tires front and back!
Good hunting, KF