Difference between the MXUS 3000W - V2 - 4Tx16 and 5Tx12?

markz

markz

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Whats the difference between the MXUS 3000W - V2 - 4Tx16 and 5Tx12?
Is the best controller the Infineon 12fet or 18fet?

I am placing the motor on a 26" mountain bike rim to see how it works out, then might go 24" heavier duty rim if I need more torque.
Most likely go with BMSBattery, batteries. In the 15Ah range. Not sure what voltage to use.
Thinking 48 is too low, maybe 60 or 72.
 
4T wind will be higher rpm.
Controller and battery requirements depends on your needs. I'll be using the same 24s lipo pack and 15 fet 40A controller I have now on mine. Match your battery pack to the controller you use.
 
The 4T has 4 more strands in the slot, so it will be more efficient. That's an extra 6.7% of copper around each tooth, so the choice isn't even close. To quantify that let's say you pull an average of 5000W during acceleration. Then from a full stop until the motor reaches 50% efficiency it averages only about 25% efficiency, so 75% loss almost all of which is heat in the copper at the lower end of the rpm scale or 3750W of heat. That's an extra 250W of heat from zero up to about 1/4 to 1/3 of top speed. Of course the losses continue, just with decreasing effect as efficiency gets higher. The greater heat leads to higher temperature, which further increases resistance and increases the extra losses for the 2nd takeoff.
 
In this case, 5000w, nice wide motor, it aint going to matter if you weigh 150 or 250 pounds. It's not going to spend 90 seconds in that inefficient rpm. Pick the faster winding if you like it's top speed better. With plenty of headroom for watts, lots of copper in either motor (cuz it's a huge motor), either winding will be fine. Pick the slow one only if it's top speed is more to your liking. This is one reason I tend to like the slow motors, I don't ride real fast on the street, and the local trails are very hard on you above 15 mph.

So your choice depends on what it is you want the motor to do. If you want fast, then pick the fast one. It's not going to be lugging unless you want to run a pedicab.
 
Ah, now I see why the attempts to continue promoting the essence of the myth, because your employer sells slow wind motors with the inaccurate description of "High Torque" for a motor that can't make any more torque than the other model it sells, and it too makes more heat because the slow wind model has reduced copper fill.
 
The "myth" is subjective. It depends on if you are talking about system performance or simply motor behavior.

The fact is that, all other things being equal (Same Battery voltage, Same Controller type & settings/Current, same tire diameter), the 4T motor will spin faster and have less torque than the 5T motor.

As far as which option is "better", you can certainly make a case that the faster wind is better, since it has a larger "pipe" for current. However that "pipe" inside the motor is restricted by the smaller "pipe" (Phase wire size) which generally is limited by how thick of wire you can get through the bearing/axle of the motor. In most cases, that phase wire is limited to 10-12AWG wire size, and this is what heats up first under high power loads.

A 4- turn motor will bake the Phase wires before overheating the windings. (Easier to replace I will grant you that). A 5-turn motor has the potential to overheat the windings before melting the phases.

If we are talking about the MXUS 3000W motors, the stock phase wires are 2.5mm^2 or about 13AWG. So realistically, one should not really be running 250 Phase amps, even if the 4T windings could handle that amount.
 
teslanv said:
The "myth" is subjective. It depends on if you are talking about system performance or simply motor behavior.

The fact is that, all other things being equal (Same Battery voltage, Same Controller type & settings/Current, same tire diameter), the 4T motor will spin faster and have less torque than the 5T motor.

As far as which option is "better", you can certainly make a case that the faster wind is better, since it has a larger "pipe" for current. However that "pipe" inside the motor is restricted by the smaller "pipe" (Phase wire size) which generally is limited by how thick of wire you can get through the bearing/axle of the motor. In most cases, that phase wire is limited to 10-12AWG wire size, and this is what heats up first under high power loads.

A 4- turn motor will bake the Phase wires before overheating the windings. (Easier to replace I will grant you that). A 5-turn motor has the potential to overheat the windings before melting the phases.

If we are talking about the MXUS 3000W motors, the stock phase wires are 2.5mm^2 or about 13AWG. So realistically, one should not really be running 250 Phase amps, even if the 4T windings could handle that amount.
Click to expand...

In this case there is nothing subjective. 64 strands of the same size magnet wire around each tooth is better than 60 strands no matter what silly conditions you try to put on the comparison. FWIW your insistence on keeping everything the same to compare two different windings is a fail, because it means at least one is running with improper controller settings. For best results, controllers need to be individually tuned for the motor, load, and use.

It's amazing that you're more concerned about a tiny bit of extra heat in 10" copper from the end of the phase windings to outside the motor, which is relatively simple to upgrade anyway, than you are about extra heat in the windings, which are many times longer and can't be changed.
 
I think I am sloooowly getting it.

So if these are the stats for the different winds of this MXUS 3000W.....
15X4: 9.00 Kv - Clyte HS - (Standard Normal Motor for the USA group buy) Fast Wind?
12X5: 7.19 Kv - Cromotor
10X6: 6.02 Kv - Clyte HT - Slow Wind?

I can wrap my head around certain points of view from the various members here on E.S.
I doubt when building any ebike you keep things the same from one to another, and I can see how the speed and torque are the same for the different motors, I also understand the more wire for the 4T, which is what you want...more wire = more efficiency. I also completely understand the tire diameter rule, decrease in tire diameter gives you more torque which results in less speed, and a larger wheel diameter gives you more speed and less torque. But if anything you want to decrease the tire to a comfortable level, I myself dont care about looks.

I just dont then understand why there would be a choice, in "Turns". For a given battery voltage your speed changes, I understand that, because of the Kv.

So most of you would recommend the 4T 15x4?
This would be an overall improvement on the famed cromotor?

OK I am going to email them and order my 4T x 15 motor.
Now for the controller, Infineon is the way to go I hear, and those Lyen Controller are even better, if not the best.
School me on this controller biz, for the mxus 3000w, ebikes 12fet 40A 72V for $190, or go Lyens 45A 12fet 72V for $130 or 65A 72V 18fet for $200?
 
Just recieved an email back from MXUS, that was quick!

Should I get this motor unlaced or laced?
I think the shipping cost will be higher if I order it laced, plus wouldnt the quality of the wheel be better if I source the lacing products myself?
Then again to get someone to lace it at a bike shop will be what? $50 minimum
I know I need a road grade rim, beefier spokes.
 
I bought a couple of 15fet 72V 40A 1500W controllers in June 2011. I've been running one of them with 24s lipo (100V) since then without a problem. They were $35 each shipped from China. Ones been sitting here all that time. I see no reason not to use it with this motor which is going into a 26" DHL wheel with a 26x 4" tire with a 29" diameter. Unloaded speed will be 77 MPH. All I want is 40 MPH without over heating and I don't see that being a problem. Lacing a rim is easy. Just takes a little time. I have no idea what they will charge to do it.
 
Baiscly, I'm still trying to say, "it depends". Of course for some situations the slow wind motor my employer sells sucks. Did I recommend the motor I sell to this guy? I sure as hell did not!

Riding in very steep terrain, with too much power for the size of the motor, I melted motors several times. So even I understand that just changing a winding does not make it a magic motor able to do anything. But when I first started riding these very slow motors, I did think that. I was wrong. All I'm saying now is,,,,,, If you want to go slow, doesn't a slower winding make sense? If you don't want to go slow, then a slow winding is stupid.

Bottom line is, you do need the right tool for the job. And if your weight is heavy and the hill steep, nothing short of more copper and more magnet and more watts will do. Once you have that, the winding you are using will matter a hell of a lot less. Either one will blast out of the start beautifully. This guy is looking at large motors, either one will work great for him. His choice should be based on what top speed he'll prefer.
 
markz said:
OK I am going to email them and order my 4T x 15 motor.
Click to expand...

Specifically ask for the 4Tx16 you put in the thread title, not the 4Tx15, even if it costs slightly more. FWIW 9rpm/volt is a common ebike wind, not what I'd consider a speed wind.

If you only want to run relatively low power, as demonstrated by your controller list, why even go with this relatively heavy motor?

WRT wheel size, proportional increase in speed with wheel size applies only to lower speeds. Wind resistance increases geometrically with speed, so powering thru it requires more torque at the ground. I have ebikes with identical motors, one with a 20" OD wheel and one with a 23.5" wheel, and they are capable of a nearly identical top end right at 60mph. With 15% more torque applied to the road the one with the smaller wheel has noticeably more acceleration, better hill climbing, and better economy. Plus the higher rpm at equal speed means not only does it make less heat because the motor is less stressed, but it sheds heat a bit better too.

If they're going to lace it up with a moto rim, then it will probably be cheaper to pay the extra shipping. If it's a bike rim, I wouldn't even let them try, because it would be best to drill the proper size holes halfway between the existing holes that are too large for bicycle spokes.
 
Thanks, ya I noticed the little difference between the V1 with 4Tx15 and the V2 with 4Tx16 as I was reading the various threads.
I am ordering the Version 2 motor with 4Tx16 for sure, more wire etc.
I have been reading up on this spoke hole dilemma, not to sure how to proceed now, I am a little hesitant.
There doesnt seem to be a readily easy solution. Perhaps I will emphasize the smaller spoke hole, if they will do it on just one order.
But your point on drilling holes between existing makes sense too, might weaken the flange a little bit, if that is even a factor.
I am one step closer, I guess.
 
With 15% more torque applied to the road the one with the smaller wheel has noticeably more acceleration, better hill climbing, and better economy. Plus the higher rpm at equal speed means not only does it make less heat because the motor is less stressed, but it sheds heat a bit better too.
Click to expand...

How is this not an argument for higher wind = lower resistance/heat?

Electrons pass around conductors, not through. More conductors = more current.

Myth or Math?
 
markz said:
Thanks, ya I noticed the little difference between the V1 with 4Tx15 and the V2 with 4Tx16 as I was reading the various threads.
I am ordering the Version 2 motor with 4Tx16 for sure, more wire etc.
I have been reading up on this spoke hole dilemma, not to sure how to proceed now, I am a little hesitant.
There doesnt seem to be a readily easy solution. Perhaps I will emphasize the smaller spoke hole, if they will do it on just one order.
But your point on drilling holes between existing makes sense too, might weaken the flange a little bit, if that is even a factor.
I am one step closer, I guess.
Click to expand...

Putting an extra set of spoke holes is simple and won't weaken the flange at all. In fact some of the manufactures have gone to cutting big U's out of the flanges between spoke holes.

It's better to go with a moped rim, tire, and moto spokes...definitely worth the extra weight. If you go the bicycle parts, then contrary to common belief, you don't want to go with thicker spokes. Quality 14ga spokes is the route to go for a longer lasting wheel. Liveforphysics was running huge power and didn't solve his spoke problems until he got with Chalo and learned how bicycle wheels need the flexibility of thinner spokes to spread the load properly. No doubt that factual statement will draw plenty of anecdotal comments to the contrary, but his stuff regarding bicycle wheels is Chalo's best contribution to the forum, and solving LFP's spoke problems is all the proof I need.

The question I haven't seen answered is whether the V2 has better steel in the laminations. Is it the same 0.5mm steel or thinner. I ventilate motors for high power use, so sinking heat away from the stator steel a bit quicker and holding more heat in the aluminum at a given temperature, which are the benefits of the V2's aluminum spokes between the center and stator steel ring do nothing for more. More copper fill is of value as quantified above.
 
Stevil_Knevil said:
With 15% more torque applied to the road the one with the smaller wheel has noticeably more acceleration, better hill climbing, and better economy. Plus the higher rpm at equal speed means not only does it make less heat because the motor is less stressed, but it sheds heat a bit better too.
Click to expand...

How is this not an argument for higher wind = lower resistance/heat?

Electrons pass around conductors, not through. More conductors = more current.

Myth or Math?
Click to expand...

Not sure what you're getting at. With the same copper in total around each tooth, differently wound motors are actually identical when compared at the same power and rpm. The higher turn count (lower Kv) motors have longer thinner copper, but require less current to make the same torque and higher voltage to get back to the same rpm. Conversely to make a speed wind motor climb a hill just like a slow wind, simply use a lower voltage and increase the current in the same proportions as the difference in Kv, and it will produce the same power at the same rpm with the same motor efficiency since it has shorter thicker copper for the same copper losses as the slow wind.

What you quoted is strictly related to wheel size, which benefits all direct drive hubmotors regardless of how they are wound.

BTW, until you get up the AC operating frequencies where skin effect kicks in, the electron flow most certainly goes through the copper. At hubmotor operating frequencies solid core wire will work the same as multi-strand.
 
"flow around conductors" sounds like a stream flowing around rocks, where the rocks represent the conductor. So, no. Current does not bypass a copper wire, preferring instead to travel to the far end of the wire via the air and soft furnishings in a room.

If you're instead referring to the literal movement of the electron cloud in a metal carrying a current, then "no" for DC and "sort of, maybe" for AC.
 
Stevil_Knevil said:
Pretty sure electrons flow around conductors, not through.

Is that a myth?
Click to expand...

Myth unless you're talking about skin effect. Electrons make full use of the copper cross section to flow through. Though it seems solid to us, the atoms are mostly empty space, so plenty of space for the flow of electrons.
 
I have been sitting here for an hour, searching ES, searching Google, and Yahoo.

Tell me what a "Slow Wind" "Slow Winding" "Fast Wind" "Fast Winding"
As far as I can tell, someone said 12T is crazy slow, DD in 10T is slow wind, 2810 - 6x10 - x5404

I was confused when I wrote this statement, I do not know if its true
15X4: 9.00 Kv - Clyte HS - (Standard Normal Motor for the USA group buy) Fast Wind?
12X5: 7.19 Kv - Cromotor
10X6: 6.02 Kv - Clyte HT - Slow Wind?
Click to expand...

Fast wind you go fast, slow wind you go slow. So the statement above is correct?
Lower Kv = Slow Wind or Winding
Higher Kv = Fast Wind or Winding
rpm/volt
 
I'd recommend the 18-FET. If the 12-FET was all you'd need, I'd get a lighter (and less expensive) motor to go with it. Big motor equal lots of copper mass (45mm wide stator), so it can take a lot of amps...

Even if a lighter motor cost the same, the 3000W MXUS is heavy. It was made for 72V / 60A+...
 
I just ran the stock 13AWG phase wires on a 3T (12Kv) MXUS 3000W up to 50 MPH or around 3600W.

I didn't do it for very long, though. It was just a quick top-speed test.

To answer your question, Markz...

Faster Wind (Higher Kv) motors spin faster per Volt than Slower Wind (Lower Kv) motors. Faster Wind motors can also handle (And require) higher phase amps, so that both the Slower AND faster wind motors produce equal torque for the same copper fill. Faster Wind motors benefit the most from larger phase wires, since they take more current to run them.

My best suggestion would be to choose your desired top speed and work backwards.

For a given top speed, you will find that you can adjust wheel & tire size, voltage and current in a variety of ways to get similar performance from all the motor speeds. - Since most guys will prefer lower voltages for safety reasons, the Higher Kv Motors end up being the preference, especially when they have good copper fill like the 16X4T motor.
 
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