which motor will give the most run time?

[auto2]

mentioned on another forum ( by someone i trust) was that the hacker motor will give longer run time than a NEU cause it draws less watts .

like to start a discussion on this topic. in 1/8 buggy you only need so much power. are the neu motors im using overpowered ? 1512 1.5y? (5s)would another motor still have adaquate power but add to my run time?

[suicideneil]

Motors dont draw watts, they make them:

Power (watts) = voltage x current (amps).

I would say compare the listed specs of a neu and hacker that have the same kv rating and length to answer that question (on paper at least).

Since a neu has 4 poles vs 2 on the hackers, I would say you could get away with using a smaller neu to do the same amount as work as a larger hacker- due to nearly double the torque being produced. A 1509 should work okay in a buggy, but I'd say look at other peoples setups to see what they like the most...

[lincpimp]

Without specific experience, I would say it is hard to determine what will pull less amps...

I can say that a hacker c50 L can motor will move a buggy around just fine.

I can also say that a hacker c50 L is very similar to a 1512 in terms of power produced, and runs slightly warmer. A 1512 is the correct size motor for a buggy, IMO.

Now I did find that a hacker c50 XL motors was between a 1515 and a 1521 in terms of power produced. But the L can seems to be very similar to a 1512.

[SpEEdyBL]

Originally Posted by suicideneil

Motors dont draw watts, they make them:

Power (watts) = voltage x current (amps).

I would say compare the listed specs of a neu and hacker that have the same kv rating and length to answer that question (on paper at least).

Since a neu has 4 poles vs 2 on the hackers, I would say you could get away with using a smaller neu to do the same amount as work as a larger hacker- due to nearly double the torque being produced. A 1509 should work okay in a buggy, but I'd say look at other peoples setups to see what they like the most...

Actually Auto2 is more correct. Motors don't "make" power. Batteries make the power, motors draw power and convert it into mechincal power. So if you switch from 30c packs to 20c packs of the same capacity, you will probably get a little more runtime as the 20c packs will not be able to supply as much current to the motor. Yeah I know, the terminology of "power" is confusing. The true definition of a "Powerful" motor is one that is efficient (enough not to overheat) and doesnt break down at high power inputs (voltage x amps). But suicideneil, I have to admit that it can be very hard to get the point across without saying that "motors" make power.

Auto2, I think this is a question that is best answered yourself. Only you know how much your setup suits you. Does your neu motor feel overpowered or not? If it does, then a smaller motor of equal kv may be better than gearing lower alone, because the smaller motor will draw less current. But since torque is a function of current (this applies for any motor; 2 pole, 4 pole, winding style, etc) the smaller motor will also have less torque, and therefore less power. Think of ratios. 2/3 the current will give you 2/3 the torque, 2/3 the power, and 3/2 times the runitme.

If your 1512 1.5Y has exactly the amount of power you need (personal preference) you can't get more runtime and keep the same amount of power output, just by changing the motor alone, (unless you find a motor that is even more efficient).

Now, 4 pole vs. 2

If you have a 2 pole motor and a 4 pole motor of equal kv and they are both drawing equal amounts of current, they will output the same torque. It doesn't matter if one's 50% efficient and the other is 90% efficient, their oz-in/amp (the amount of force 1 inch away from the shaft, per amp) = 1352/kv - a fixed number that only depends on kv, nothing else. The only differnce is that the 50% efficient motor will be spining at half it's kv and the 90% efficient motor will be spinning at 90% of its kv. It just so happens to be that 4 pole motors may be more efficient than 2 pole motors, so 4 pole motors can get away with pullimg more current to make torque. However, there are good 4 pole motors and there are bad 4 pole motors and a good 2 pole motor can at least be almost as good as a good 4 pole motor.

[Oppressor]

Originally Posted by suicideneil

Motors dont draw watts, they make them:

Power (watts) = voltage x current (amps).

I would say compare the listed specs of a neu and hacker that have the same kv rating and length to answer that question (on paper at least).

Since a neu has 4 poles vs 2 on the hackers, I would say you could get away with using a smaller neu to do the same amount as work as a larger hacker- due to nearly double the torque being produced. A 1509 should work okay in a buggy, but I'd say look at other peoples setups to see what they like the most...

I know that i am new here but logic tell me that if 4 poles motors were twice as good as two pole motors there would be no two poles motors on the market and even if a four pole motors had really two time the torque potential of a two polers the controllers and motors would burst in flame way before reaching such torque level as most motors are much more limited by heat than by their magnetic strenght. At that level sheer size and efficiency count and an hacker is nearly as efficient i believe.

Manufacturer aren't stupid, while the hacker have two time less pole each of them have two time the repulsion strenght(two time more meterial). It's like comparing kick to punch. Sure you can punch faster but a kick is a kick.

Of course it hold true only for motors of about the same mass.

The real questions, i believe, should be:

1 Will the motor stay cool enough for my need? (Keep in ming that larger motor radiate more heat)

2 Can it be tamed? (Think power over torque as ultimately it's power that decide how fast it move and accelerate)

3 Can it's power be transformed for my need? (High rev motors with low torque can be geared down to raise torque at wheel and low rev motors with high torque can be geared up to turn the wheels faster.)

Theorically it would be possible to need an overly larger motor for it to stay cool but that would be hard to tame. (Think kb45 for a erevo for example).

Even a single brushed 400 can motor could move a gst 7.7(Would probably need a machinist for gears though). It all depend on how fast you want to move your model (power).

If you want to draw less watt you will have to ask for less power which mean making your model move slower. Also accelerating slower and less often would help but it kinda get in the way of such a thing as fun ;) Smaller motor and esc amp limit could help taking less energy accelerating as you would accelerate less often for a given time period.

A big motor could be surprisingly close to a smaller motor in energy consumption as electric motor have a tendency to take more and more energy till they reach it's rpm or burn trying meaning that a model with a neu 1515 or a neu 2230 would take nearly as much energy to sustain the same speed the difference being in the motor weight to lug around, it's rotational inertia and a slight effeciency difference due to one of the motor being closer to it's ideal power curve.

As for what motor will work well i don't know

[auto2]

hummm, interesting. one thing for sure the neu runs cool. i never checked what gear im running in relation the motor RPM. i do know I can gear it up at least 5 teeth on the pinion and it still runs at most warm and that speed is a good 50 +MPH
BTW running a 808 with MMM and 5s 3700 enerland 16 or 17t pinion for the track

[molak]

The one that produces the power your need at the higher efficiency..

It´s a complex matter... It depends on how you gear it, the effieciency "curve" of your motor, the efficiency of your ESC and how you drive it.

Batteries are your power source, a limited one, so each time your slipper slips or your wheels spins, you are shortening your run time..

pd: the efficiency curve should be a 3d map rpm, torque and volts.

[Patrick]

If you set both motors (1512 and C50L) up so the car drives basically the same around the track and putting out the same power then there shouldn't be too much difference in runtime, probably not even enough to tell if it's the motor or inconsistencies in your driving. The only difference should be down to motor efficiency which I would say is slightly better on the neu, but it won't be huge.

Motors do draw watts, they draw watts to make watts. Efficiency is the % they put out compared to what they use.

If you have a 2 pole motor and a 4 pole motor of the same size and kv, the 4 pole motor isn't going to have twice the torque of the 2 poler, because to be the same kv as the 2 pole motor it has to have a lot less turns, and lower turn motors have less torque. If you do have twice the torque from the 4 pole motor it will be half the kv, so in the end it will basically even out. You don't get things like double the torque without sacrificing something else (kv in this case).