teslanv
1 MW
Great graphic, Teklektik.teklektik said:
Mind if I borrow that?
muxus 3000 chugging ?
- Thread starter 999zip999
- Start date
Mind if I borrow that?
999zip999
100 TW
Teklektik ( what does that stand for ?) So don't you need amps for that chart to work.
Tesalnv I sent the motor out. Good if you chose to fix.
Tesalnv I sent the motor out. Good if you chose to fix.
teslanv
1 MW
Amps will affect torque and accelleration, but not unloaded speed.999zip999 said:
You will need higher amps to get the very most out of your loaded speed, since more current will allow you more total power at any given voltage, and push harder against the air resistance at higher speeds, but it is voltage, higher Kv and tire diameter that ultimately determines the top speed.
999zip999
100 TW
What does kv fill like.
arkmundi
10 MW
What do you have? 3T? 4T? Group buy version or version 2.0? Thanks.teslanv said:
teslanv
1 MW
I do not have any at the moment, but will be placing an order with MXUS in the next few weeks. I can order whatever you want.
The Version 2 will be available, but it will be a little more expensive.
I can also have it laced in a Moped Rim. You will just have to pay for whatever difference the final cost is.
The Version 2 will be available, but it will be a little more expensive.
I can also have it laced in a Moped Rim. You will just have to pay for whatever difference the final cost is.
arkmundi
10 MW
Can I get that unlaced but with the smaller 2.5mm spoke holes intended for 13/14 gauge spokes? I already have a rim, spokes and tire. Assuming same dimensions so my spoke calculation remains the same. Thanks. You're awesome.
John in CR
100 TW
999zip999 said:
Primarily because MXUS believes the myth. There are reasonable reasons though for a slow wind if high power and speed aren't a priority, and they're mostly to be able to go cheap on the controller and wiring, not torque, heat, and efficiency. Plus it wasn't too many years ago that high current controllers weren't readily available, and lesser controllers fried while trying to push speed wind motors. The rapid growth in high powered scooters forced the Chinese to develop controllers to push those higher Kv speed wind motors, so controller availability isn't an issue.
teslanv
1 MW
I am not 100% sure if MXUS is able or willing to do the smaller spoke holes, but I will ask.arkmundi said:
teslanv
1 MW
Yeah, if you want high torque while keeping current low (Because you have a low-powered Controller and small wiring), then you would choose a Low Kv motor. You would do this with the understanding that top speed would be reduced, as compared to a higher Kv motor.John in CR said:
The other good news is that copper prices are at a 5-year low, so now it is not so expensive to install big-ass battery & phase wires on your rig.
John in CR
100 TW
But then you might as well go with a smaller lighter motor too, because torque per amp is exactly the same for motors with the same Kv. The reason to go with a bigger motor is to get more power and speed.
teslanv
1 MW
Well, there is that...John in CR said:
I have to say, I was surprised to find that Kt is inversely proportional to Kv, regardless of motor size.
For every motor, Kv x Kt = 7.04375, or Kt = 7.04375/Kv so Kt (Ft-lbs. of torque per Amp) can be calulated if you know the Kv of a motor.
What matters is how much current the windings can handle, and larger motors can handle more current, and therefore produce more total torque with less waste heat.
Here is a list of the MXUS 3000W Kt Values, based on Winding Pattern:
21x3T (12 Kv): 0.587 ft-lbs./Amp
16X4T (9 Kv): 0.783 ft-lbs./Amp
12X5T (7.2Kv): 0.978 ft-lbs./Amp
10X6T (6 Kv): 1.174 ft-lbs./Amp
wesnewell
100 GW
I know the halls are right now. I had them wrong to start with. Reference post above. No way of measuring current draw without sticking the watt meter in the middle of the 24s pack, but I get virtually no voltage sag unloaded, so it can't be much. Controller does not get hot. I do have a spare 48V 30A controller I could hook up with a watt meter to test if it comes to that, but I'll have the tach by the end of the month. I'm in no hurry. Are there any markings on the motor that indicates the windings? if not, you may want to suggest they start doing that.teslanv said:
999zip999
100 TW
Teslanv I have tried and mapped all 36 combos. John so a 5t gets less hot and easier on controller and phase wires over a 4t ?
teslanv
1 MW
wesnewell said:
MXUS marks the stator with the winding pattern.
See 999zip999's photo below. His is marked as a "12X5" (12 strands x 5-Turns) This may involve removing the cable side cover which can be a bit tricky.
The non-intrusive way is to sample the RPM at a known voltage and calculate the Kv. If it is truly a 4-turn motor, you should get around 9 RPM per volt.
A Digital Laser tachometer is cheap and handy. http://www.ebay.com/itm/New-Digital...467?pt=LH_DefaultDomain_0&hash=item20dc9a654b
John in CR
100 TW
999zip999 said:
There is NEVER any reason to try 36 combinations.
No a 5 turn doesn't get less hot unless it is making less torque. Everyone needs to let go of the myth and all the different ways it is worded (better hill climbing, more efficient at low speed, high torque wind, and all the other garbage). Even when using the same battery and controller and settings it only makes slightly more torque, but only from 0 (so it has jerkier starts) up to a surprisingly low rpm. Above that point the torque curves cross and the speed wind motor makes more torque, and that torque gap gets big quickly and stretches all the way up to the top speed of speed wind motor. The torque advantage of the speed wind extends for well over half of the operating range, so it's actually the speed wind motor that is the higher torque motor. Once you add in that those pushing high power typically can't even use the full low speed torque available with the slow wind, because the common short wheelbase high CG ebike will flip, the torque advantage of a slow wind motor run with the same settings and voltage all but evaporates.
Apparently there are some geared hubbies where the manufacturer makes no real attempt at good copper fill, and they simply put more turns of the same thickness copper for the slower winds. In that unforgivable construction case, the slowest wind is the best motor because it has the most copper, but looking at the stator picks I saw even the slow winds had poor copper fill, so I consider that entire line of motors to be junk. Know what you're buying.
999zip999
100 TW
John I do understand and read most all of your posts. I'm triing. Plus I did the long math of 36 combos just to check. I found only two working forward matches. Yes I'm an ebike caveman and never be Tesla or Dustin. I would need to try a 4 and 3t to understand. This must frustrating for you sorry John. Just a little thick. They found a vinegar battery in are family cave, maybe 3,000 yr. old or more square wheel with three phase motor. If great grandpa would have use a round wheel. Oh well.
wesnewell
100 GW
So you order 40 motors of various windings and there's no way of telling them apart without either taking them apart or putting them on a test rig to check rpm. With this being the case, I'm wondering how you separated the ones you got or even know if you got what you ordered? And how does the end user know what he got> A simple half penny paper sticker on the motor casing would take care of all this.teslanv said:
999zip999
100 TW
That's if the sticker doesn't fall off and a China worker puts it back on some odd motor. But good point Wes, they would have to stamp the axle or ? Something that's not interchangeable. I mean in the long run.
teslanv
1 MW
Actually I was very insistent that MXUS label clearly all of the various windings. (There were three different options.)wesnewell said:
They were shipped three or four motors to a box, and each box from MXUS was labeled with a 4T, 5T or 6T, and I verified the total count for each winding matched the Order, which they did.
When I opened the boxes, I relabeled each motor with a 4T, 5T or 6T with Blue tape before I transferred them to individual boxes, which I also labeled with the corresponding 4T, 5T or 6T.
Wes, If you did in fact end up with a Slower wind motor, it would be because MXUS slipped one in a box labeled as 4T.
Regrettably, I did not Kv Test each motor to verify Speed/RPM before boxing it up. Good to know for future reference, I suppose.
999zip999
100 TW
Teslanv there wasn't blue tape on mine, maybe your China man took it off. Meaning a steel stamped motor from Muxus ? Let's not push them over the edge, but might be good for muxus in the end to mark there motors.
teslanv
1 MW
For all future orders I will be Kv Testing them before they go out. It's the only way to be sure.999zip999 said:
Ya - but checking the phase-to-phase resistance would be easier and would let you identify the turn count once you got the baseline resistances for each.teslanv said:
You can either do the iCharger/Voltmeter trick (or variations) and compute the resistance, or (since you will be doing a bunch) you might consider a little adapter I ran across that plugs into your DMM and allows you to measure milliOhms as milliVolts directly on any DMM.
Here's a post about it.
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