[akim]

What's the difference? (new to RC)

[Michael Hyatt]

I'll make it as simple as possible,

A brushed motor has two brushes which transfer electricity to the wire coils and create a magnetic field to make the motor run. The more power applied, the faster the motor spins. The big drawback is the brushes wear out quickly, waste electricity and create a lot of heat.

A brushless motor on the other hand uses an electronic speed controller, which sends electronic pulses to the wire coils to create the magnetic field and make the motor run. The power remains the same, just the pulses are faster or slower to increase or decrease the speed of the spin. The brushless motor doesn't have brushes to wear out so it lasts forever (in comparison to brushed), is more energy efficient and creates a lot less heat.

Try here for a more complete explanation,

http://en.wikipedia.org/wiki/Brushed_DC_Electric_Motor

http://en.wikipedia.org/wiki/Brushle...electric_motor

[orenda635]

Brushless motors are always better choice. Especially in serious off road environments. Brushed motors require vents to cool the armature. Since the coils on a brushless inrunner motor are mounted to can, the can acts as a heatsink. So they don't need active cooling. This means the motor can be fully sealed and thus can operate in dusty, muddy, or water environments. This makes them ideal for off road trail trucks or anything else that's likely to get vert dirty. With brushed models, you'll have to keep the motor clean. Brushless are virtually maintenance free.

The downside is cost. Brushless require more complicated electronics. They're three phase, alternating current motors. Hence the three wires. The ESC converts DC to AC using an inverter. There's also a microchip that controls phase. A brushed ESC is basically a potentiometer. Very simple and thus cheaper. A quality brushless ESC typically costs almost double that of a comparable brushed controller.

What you choose really depends on how much you're willing to spend. Brushed motors are perfectly good enough for light driving. Especially for on road vehicles. Even if the brushes go, the motors are very cheap to replace. Often just $20 for a basic, quality motor. If you drive a lot or want to get competitive, brushless is the only way to go.

[Cougar429]

Along with the forementioned advantages brushless motors are also more efficient. With brushed motors you can expect 50-60% efficiency, which means almost half of the power being fed to the motor is lost. Brushless are in the low to mid 80 percentile and that means you can get more power output for the same current.

Brushless motors are also what is called 3-phased. The three wires from the ESC to the motor carry not only the pulsed outputs to create the fields in sequence as Michael Hyatt described, but the ESC also measures a feedback from each phase to correctly set up the timing sequence. This is all done automatically and is invisible if the ESC and motor are matched correctly.

As for the ESC's many have programming options you can access and set, such as brake, timing, cut off, etc. Each option can be set independently and would depend on your application. Until you get a feel for them it may be best to leave them in default as that should at least get you running decently.

There are disadvantages, one being brushless motors have what is called a "Sweet Spot" RPM/V. If lugged down with too much load, the wrong Kv for your needs or an improper gear ratio then their efficiency falls off dramatically. Easy enough to tell as the motor will be too hot to touch at the end of a run. That's why it's best to try and figure out the RPM you require and find a motor that fits that spec.

The second concern is that the rest of the power system is strong enough to tolerate the higher current demands. If your battery is capable with a brushed setup it may be marginal with a brushless. The connectors also need to be capable of the extra draw or run the risk of melting.

This is not to discourage you to do an upgrade, just make you aware of some of the differences. As for cost this is pretty much an "How much do you want to spend" as there are now a lot of lower priced HK offerings of decent performance. If you want reliability I always rate my ESC max current at 1.5X what I expect I will ever need to feed the motor.

I would advise you to do some research on the intended application. Hopefully someone has already fit a brushless raw or done the swap and will have some recommendations. On that note, were you looking for something specific?

[photecs]

Go to YouTube and search "how a brushed motor works" and "how a brushless motor works". There two videos by the same guy that has a cad drawing on the screen and he talks you through what each type is all about, while taking the motor apart.... Tough accent, but it's a good learning video. Watch the brushed one first....