Motor magnets and rotor - lack of breaking

[martgifford]

If my motor lacks brakes in my 4wd due to the motor being worn/used. If I replace the rotar with a new rotar will this give me more braking?

Ie how does a motor wear - is it the rotar or can
Thanks

[metalmickey0]

Personnaly i`ve never heard of a motor wearing causing it to lack brakes. i would check your esc to see if you have brakes at 100% or 0

[Jamie.T]

Over time your rotor will loose its magentism and essentially "wear". This will result in poor brakes and a new rotor is normally sufficient. But bare in mind once the motor has done that much work the sensor board and bearings have done a fair amount of work, so your usually better off replacing the whole thing.

I know the old novak velocity motors used to loose brakes a lot over time due to the rotor loosing its magentism, espcially on the cheaper bonded rotor versions.

[martgifford]

I heard from someone that a brushless motor does wear. And it wears by losing its brake ability as the magnet lose their power...

[SlowOne]

Brakes, rotor, braking, lose, you're, and so on. I feel better now...

Brushless motors wear the same way as the brushed motors used to, with the obvious exception of the brushes and the commutator. That means the magnets in the rotor, and the bearings in the can.

The magnets will lose strength over time due to the heat they have to cope with. That's made worse if you use the brakes a lot. As their strength reduces, the brakes will be less effective. In a BL motor the brakes are applied by firing the coils against the rotor rotation, and that generates a lot of heat. The same applies if you use a lot of timing-on-the-fly (boost and turbo).

Bearings usually last a long time. They're easy to check, just pop the rotor in the bearing when it's outside the coils and spin it. If it spins the bearing is fine, if not it can be replaced.

The most likely explanation is that the rotor has lost some of its magnetic strength and thus the braking performance is reduced. If the motor is a popular type, the rotor has value to people running blinky classes, especially in 1S, as a low-strength rotor is actually a plus. I'd try checking the speedo setting first as metal mickey suggests, and also confirming that the speedo is still applying brakes. Put the motor in a mates car and see if you get the same result.

If it is the same, then a new rotor is much less than the cost of a new motor, and would be the fix of choice. HTH

[RudolfXC]

Originally Posted by SlowOne

In a BL motor the brakes are applied by firing the coils against the rotor rotation, and that generates a lot of heat.

Doesn't the brakes work by shorting out the stator coils?

To test the brakes you can also apply full brakes and spin the transmission to feel (and hear) the brakes working.

[DCM]

You can lose magnetism in your rotor, but usually poor braking is a mix of esc and motor. Older motors will have less braking efficiency than the newer motors, thats the development process.

[MattW]

From the tests we've done, some brands of motors / rotors hold their magnetic field very well, and some lose it very quickly!!

[martgifford]

Originally Posted by MattW

From the tests we've done, some brands of motors / rotors hold their magnetic field very well, and some lose it very quickly!!

What are the 'best' ones?
Whete did speed passion and Lrp stack up

[MattW]

I'd say that speed passion rotors generally tend to hold quite well

[DCM]

I am on old Tekin Redline motors, loads of brakes.