190KV or 230KV For Quad Loangboard Setup?

Hello guys,
I am starting an ambitious project. I'm designing a 4WD electric long board and I am currently researching motors. I am stuck between the enertion r-spec 190kv and the alien power 6355 230kv. I want the board to go 35-40 and am unsure if having 4 r-specs at a very low gear ratio would be as good or better than having 4 230kv motors at a higher gear ratio. In my mind it would seem like the 230kv motors might do a bit better. What do you guys think?
Thanks a bunch!
Josh

IMO Because you have 4x.. I'd go 230KV. You don't need that much torque. I also run 230KV on a dual motor setup too.

Alright cool, that's kinda what I was thinking. What motors do you have and how have they held up if you don't mind me asking?

I have 6355 230KV motors on my site. Most motors will work great and will last you a long time.

Typically, the only time motors will fail is if motors get caught up when running, stuff just fails or the most common would be getting too hot (motors being over-worked).

Some are better than others but most are ok.

Ok cool, actually your motors look perfect as I am planning on using a 12s pack. What sprockets would you recommend for it considering the 4WD? Also, does the sensor interface with the VESC controller and would they be available in non-sensored versions? Which version would you recommend for use with the VESC?
Thanks a bunch!

12s with 240kv is not a good idea. The kv is too high for this voltage. You should either go 10s or use a lower kv motor.

@S28400 -with a 4wd, you can probably get away with building a faster system if you wanted too and go for a gearing ratio which is 1:1.8 or so versus the standard 16:36 which is 1:2.25.

If you use the VESC and the 230KV. You'll want to limit to 10S battery. Currently, it doesn't work with 12S and 230KV+ kv ratings.

Hi
Holy smoke mate, what do you want 4 motors for?
2 x 63mm motors is already a beast, 4 x 63mm motors is just overkill. You will not be gaining any top speed, only acceleration (if one can handle it) or serious hill climbing ability.
I could possibly understand 4 x hub motors but 4 geared motors?
Of course everyone to their own, no reason not to I suppose. (Well apart from expense and weight)

akiraEC said:

12s with 240kv is not a good idea. The kv is too high for this voltage. You should either go 10s or use a lower kv motor.

Click to expand...

I agree with this. 240 kv x 48V = 11,520 romantic, which is well over what Vedder concludes is optimal. The 190 kv would have a maximum romantic of 9,120, which is very close to his target of 8,600.

WeeChumlee said:

Hi
Holy smoke mate, what do you want 4 motors for?
2 x 63mm motors is already a beast, 4 x 63mm motors is just overkill. You will not be gaining any top speed, only acceleration (if one can handle it) or serious hill climbing ability.
I could possibly understand 4 x hub motors but 4 geared motors?
Of course everyone to their own, no reason not to I suppose. (Well apart from expense and weight)

Click to expand...

I agree with this, too. I'm running a single 192kv SK3 6374 at 12S and it rips. I can'tell imagine dual wouldn't be more than enough for any hill!

Do you plan on rolling up pike's peek? or pulling a group of longboarders up hills?

Surely overkill for anything else.
its going to weigh at least 50lbs to have enough batteries for 12kw!

anyways take lots of video and set an uphill speed record! 8)

Yes, I was just reading about the kv being to high on other forums. It would be better to keep the voltage high and lower the KV to keep the motors running cooler? Is is possible to limit the voltage via the vesc? Also yes I helped a senior design student build a dual drive system with the r-spec 190kv motors and the thing rips. My main goal for the 4wd system is to distribute the power over the wheels for better traction, braking and unprecedented acceleration. My battery pack consists of 36 a123 26650 cells and the bms system on it allows it to push 180A continuously so I plan on feeding ~40 to each controller. I was also considering using 4 smaller motors rated for around 1.5KW but I can't seem to find any that operate at 12s voltages or KV's around 200-300.

Ok so I think I have it figured out. I first want to point out that when I say 12s, I mean 12 of the 26650 LiFePO4 cells with a nominal voltage of 3.3v. Fully charged they are 3.5v. I did some calculations and figured that the 230kv motor would be better suited for my application as at 37v it is at 8510 rpm. I also discovered in the vesc settings, you can set a maximum voltage. Setting this to 37v would ensure that the motor is getting 37v for the entire charge cycle. Here are my other calculations, let me know what you think:

Motor kv: 230
Batteries: 37 volts
Load factor: 100%
Motor speed: 8510 (rpm)
teeth big pulley: 36
teeth small pulley: 20
drive ratio: 0.556
Diametre of wheels: 75 mm
Circumference of wheel: 235.62mm
Top Speed: 66.83738371 kph
Top Speed: 41.53082478 mph

Here is also the alternative version with the 190kv motor:
Motor kv: 190
Batteries: 40volts
Load factor: 100%
Motor speed: 7600 (rpm)
teeth big pulley: 36
teeth small pulley: 22
drive ratio: 0.611
Diametre of wheels: 75 mm
Circumference of wheel: 235.62 mm
Top Speed: 65.65928646 kph
Top Speed: 40.79878909 mph

those are pretty much the same batteries that boosted uses, x3 so you should be fine.

The vesc setting is more of an upper limit, it won't regulate it or anything so you'll still get 42 - 38ish full to empty and 44/45v on braking...

the more i think about all the mechanical i'm just seeing headaches and tuning...why not go with a quad hub motors from the forum members?
since its 4x torque on high voltage you'll have plenty of acceleration and you can go ahead and break the speed record while your at it.. its been..weeks

I looked into the hub motors, but the acceleration and torque seemed poor, even when considering a 4WD variant. I'm coming from a boosted board dual plus and I want to at least double that acceleration and torque. I also want to have modular wheels so I can swithc the wheels out for large off roading ones. With hub motors, the larger diameter would kill the torque completely.

4wd...I was thinking about climbing trees with this bad boy. Most of the time 2 wheels is fine, but what about if you want to do some serious off-road boarding? 4WD might come in handy. And we all know how inconvenient it is to have to step off ur board and pick it up and walk to where you can ride again...geez...why can't I just ride up the side of that cliff? ;P