@PixelatedPolyeurthan Lots of love giving and many many posts for 50 days straight 
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Well that is not hard hahahaha
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Yup, just saw that. Now youâre a regular here, too. 
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10char
I havenât looked but it isnât necessarily wrong. If you put the same low motor current through 2 different size but same kv motors you will measure the same torque, but if the resistance is different, the same motor current will draw a different battery current (more battery current for the higher resistance smaller motor at the same rpm same torque same kv same motor current).
The larger same kv motor might be able to handle more motor current before the iron of the stator becomes fully magnetized which is called magnetic saturation. If the larger same kv motor can handle more current, then it can produce more total torque, because same kv motors produce the same torque per motor amp â so more amps means more torque and lower resistance means less heat, and lower kv means more torque per motor amp.
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Tldr
10char
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So basically because both motors can handle a max of 80amp, only the stator determines the motors torque.
Can you explain this differently, i am struggling to understand. Maths has never been my strong subject even though i really love physics
I appreciate you tuning down the overly scientific explanations. I find answers like these most beneficial to the community.
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The torque per motor amp is directly proportional to the kv.
You can state the kv in either:
-RPM per volt no load
or
-Radian Per Second per volt no load
^When you state the the KV in radians per second per volt, then you get the torque per motor amp in newton meters from:
1/KV = Torque_per_amp_newton_meters
if you want to do this in one step from RPM per volt KV instead, you can use:
60 / (2 * pi * KV_rpm_per_volt) = Torque_per_amp_newton_meters
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More basically:
(Battery Voltage) X (Motor Kv rating) = RPM (revolutions per minute) of the motor.
Clearly, a higher motor Kv rating will make for a higher RPM.
i.e. higher kv motor is better for higher speed.
A low Kv motor has more winds of thinner wire, it will carry more volts at fewer amps and can produce higher torque. A high Kv motor has fewer winds of thicker wire that can carry more amps at less volts and spin at higher revolutions.
From there, calculators will use your wheel size (larger wheels take longer to make 1 full revolution than small wheels because larger circumference) and your gearing ratio (pulley ratios or gear ratios depending on belts or gears) to calculate how fast you will go.
Direct drive motors have a 1:1 gear ratio. One motor turn equals 1 wheel turn.
Belt setups with, lets say, 12 tooth motor pulleys and 60 tooth wheel pulleys have a 12:60 ratio or more simply, a 1:5 ratio. One motor turn equals 1/5th of a wheel turn.
Lower gear ratios (1:1 = 1/1 = 1 vs. 1:5 = 1/5 = 0.2) result in higher torque setups.
Itâs just all a game of balancing.
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not necessarily, the following 3 systems should have identical thrust and top speed given the same motor current limit:
190kv, 2.4:1 ratio, 60mm tire
95kv, 2.4:1 ratio, 120mm tire
190kv, 4.8:1 ratio, 120mm tire
You changed another variable, wheel size.
And then changed gear ratio.
All of which I alluded to. Donât overcomplicate professor, I was speaking in laymanâs terms and elaborated further.
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Iâm not sure what was exactly meant by this paragraphâŠ
yes a higher kv motor has less turns of thicker wire when the rest of the motor is constructed the same, giving lower resistance for the same motor size, potentially giving higher kv motors an advantage when appropriate gear reduction is used â especially since a higher kv motor with the same km (size constant) puts out the same torque for the same copper losses as the lower kv motor. the higher kv motor requires more motor current to produce the same torque as the lower kv motor, but since the resistance of the higher kv motor is lower, it turns out the same torque generates the same heating regardless of kv for the same km.
no, neither will âcarry more volts at fewer ampsâ â they can both receive the same effective voltage from the controller and they can both receive the same motor current from the controller â the motor with half the kv has twice the peak torque and half the peak rpm for the same voltage battery and same motor current limit.
Motor winding wire resistance exists. Iâm not laying any massive hybrid scenarios out here boss. You keep saying they âcanâ do this or that. Yes, of course they can. Theyâre dumb motors and will suck whatever voltage and current they can take before dying. Iâm simply stating the design intent and history of different Kv motor windings.
I understand you did lots of research on the hummie motor project. In the immortal words of the ghetto boys, âreal gangsta ass niggas donât flex nuts, cause real gangsta ass niggas know they got emâ
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itâs true a higher kv motor with the same km can âcarry more ampsâ because if the kv is doubled at constant km (size constant), then double the motor current produces the same heating as before in the motor, and generates the same torque. this is where you start bumping into the limitations in the number of amps the controllers which we commonly use can put out â because if you double the number of amps you send to the motor to get the same torque and heat with a doubled kv (same size/km) motor, then even though the motor doesnât heat up any quicker than before for the same torque at the same rpm, the controller heats up 4x more quickly, thanks to I^2R=W. the reason the doubled kv same size motor doesnât produce more heat with double the motor current is, when you halve the number of turns to double the kv, it halves the resistance, and when you double the thickness of the winding to keep the same size, it halves the resistance yet again, giving 1/4th the original resistance for double the kv, same km (& 1/2 the kt or torque per amp).
^ The winding conductance is the inverse of the winding resisitance (1/resistance = conductance â as the resistance decreases the conductance increases), here you can see a representation of how (at constant size/km!) the KV increases at the square root of increases in the winding conductance. For example square AMQP has double the area (conductance) of square AFGH, and in such a scenario the kv increases by a factor of the square root of 2 or sqrt(2) or 1.41421âŠ, or proportionally to the change between line AF and line AM. So doubling the KV (line AF->AN) with constant KM requires 4x the conductance (square AFGH->ANSR) or 1/4th the resistance. This relationship is not maintained if the km or size constant changes (for example if a different copper volume is used in the winding).
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I donât see an enclosure on your list. If I could be of assistance, it would be to choose your items in a different order. Donât choose anything else until youâve chosen your deck and enclosure. Because you need to know if it will even fit. Enclosures are much more difficult than you think, and you need to know if flexibility will be something you design for, or not. So go in a certain order, along the whole way making sure you choose things that are compatible with each other.
- helmet
- deck + enclosure
- battery
- ESC(s)
- drivetrain & trucks
- wheels
- motors
- {everything else}
- remote
- aesthetics: grip, colors, lights
Leaving enclosures until last as an afterthought is a surefire way to end up in less-than-ideal position.
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Good advice! But torqueboardâs battery comes with a enclosure for battery and ESC. And the enclosure fit on the 9 two 5 deck.