It’s the bin labeled “For Customer Builds”
He verry good Video fore basic
3 Likes
Or can get the kv on the bldc tool easily looking at erpm, voltage, and divide by how many magnet pairs.
2 Likes
Battery 60V 5A 190KV have more Torqe all time
Battery 30V 10A 140KV
Have the same Power in the moto 300Watt
That could underestimate the kv for 3 reasons:
-
the motor only sees 95% of the battery voltage maximum because of the duty cycle limit
-
the true kv is measured at 0a current, 100% duty (bemf = bat v), so you have to spin the motor faster than it will do on its own because of the iron losses leading to no load current
-
the motor spins slower if you are in foc mode than if you are in bldc mode because the sine wave lowers the effective maximum voltage
1 Like
is there a way to convert ft/lbs torque to pull force?
i ask wondering what chain tension will result from 10 ft/lbs from the motor. seems a smaller chain is quieter and looking to find the smallest that will satisfy the strength needs
1 Like
this is a good answer @ross_forp thanks. 
i stuck it in the original post.
thanks @hummieee for asking more good questions about the equations and leading to that.
2 Likes
Divide the torque in Newton meters by the radius of the pulley in meters to get the force in newtons, then you can convert newtons force to pounds force or kilograms force.
4 Likes
nice math skills you have. you can tell who 's who around here by their math skills.
1 Like
Sorry fore this porn 
3 Likes
So adding voltage… is it just allowing amps to flow more easily or what because with pwm making an effective voltage, which then enables the desired current, how does adding a higher battery voltage equate to more power?
If it were a bulb or any resistor I can imagine a current at such and such voltage multiplied to give a wattage but I don’t see that in the motor.
More tension is more efficiency.
Transistors and also motors.
Voltage is like the pressure that presses on the magnets, not just the current.
It’s less resistive losses as the same energy can be transferred with less current. Of course at some point the energy will like to fly somewhere rather than do what you want it to.
1 Like
Current is the quantity of electrons moving voltage is the preset and there for the speed that there moving at. combine thay make the wattage that will result in the pressure on the magnets.
1 Like
why does a lower KV motor have more torque?
Because it behaves like an ignition coil / throttle coil. There is a kind of induction voltage which results in more pressure because it builds up a larger static magnetic field.
I agree with you URI PUI set. But not all watts are the same. Look at how it is with asynchronous motors as they are there. They will be the future at some point. Our controls are not ready for the public yet.
Because tork for us only limiting factor a low RPM for ESK8
A 100kv motor vs a 200kv motor at 1mph 100kv motor PWM is on for double the amount of time than the 200kv motor. (There is a few other losses in lower KV motors l but only small amount) this is also presuming that have the same gear ratio so the 200kv motor can go almost double the top speed
Hey Kids.
TLDR.
I’m pondering upgrades for my flux build.
running off a Unity.
currently have a 12s10p 30q pack. 30Ah
going to a 12s9p BAK-N21700CG pack for 45aH.
I have the TB 190kv 6380s on there.
they have been just great.
will I be happier if I go to the flipsky 190kv 6384?
guessing this is negligible.
will I be happier if I go to the flipsky 63100s
thinking this could be nice.
what would Jesus do?
Does the flux have gear drives? without them, I don’t think 100’s are a good idea.
Unless you’ve had maintenance issues with the TB’s or want to go to a sealed can, they’re probably fine
4 Likes
it currently has belts…
I also ponder getting the bn drives.
the flux runs totally fine…
in fact I should not mess with it…
but I can’t help myself.
one thing I want to do with the larger battery is go from 14/72 to 15/72.
so if I do get a bumb in torque from the 63100s that would be welcome.
3 Likes
Just some few things I think it’s important to point out, keep in mind that I just skimmed thought it all since there was 300 messages since last time I looked here
1 - Doing efficiency calculations using only copper losses is wrong and non representative of real life usage, you have to include a core loss model, specially since we see bigger and bigger motors these days, I bet that for most riders core losses are bigger than copper, so you would benefit from actually making the motor spin slower and increase motor current limits to have the same torque as before
2 - Only way to actually make any useful comparison that it’s not just blind testing is using ride data for your specific board with you riding, the more the better, so you can get a pretty good sample size, having that on hand plus a representative motor or motors models, you can “easily” find the the best ratio and motor combo for your riding/terrain style. If you go a step further you can even have a thermal model of each motor and find the most efficient setup that still has the same torque as before and wont overheat
3 - Just reiterating, comparing voltages, motors, ratios and etc on single point is useless, as in X setup is Y when I accelerate at Z throttle
4 Likes