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ESC Testing and Comparisons

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05-13-2026 | 10:27 AM

#46

OffRoadJunkie

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Quote:

Originally Posted by DirkW

I believe his question is what happens inside the ESC when you apply the brakes.

IIRC in the brushed days, the two motor poles were shorted somehow and that created a braking force. Not sure about brushless systems. Never really cared for the details, tbh.

AH...
I took it as him asking why his brakes keep activating when off the throttle. I see, now, that he may be asking how the ESC turns the motor into the brakes.

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05-13-2026 | 10:33 AM

#47

OffRoadJunkie

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The ESC turns the motor into brakes by shorting out the stator. This creates a magnetic pull that will not allow the rotor to turn very easy. Basically, it turns the motor into a generator with an extremely large resistance on it.

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05-13-2026 | 01:56 PM

#48

gigaplex

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Quote:

Originally Posted by Mac The Knife

Back in the day with brushed motors, it was called regenerative braking, as they used the motor as a generator, and instead of using a resistor to short across, they directed the energy back into the battery. Brushless motors I assume would do the same, but they add the ability to change the pwm frequency of the braking for smoother, or more aggressive braking.

Brake PWM frequency isn't unique to brushless. My old Novak GT7 had adjustable brake frequency.

05-13-2026 | 03:04 PM

#49

Burl Swift

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Quote:

Originally Posted by DirkW

Yup, you got it. And thanks for the info.

I club race and I drive a very HEAVY SCT on some nights, my brakes are garbage when I try to get it slowed down at the end of the straight, I had always assumed it was my motor not having the strength. Now I'm thinking its the ESC.

Either way, I need to put the SCT on a diet.

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05-13-2026 | 06:11 PM

#50

OffRoadJunkie

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Quote:

Originally Posted by Burl Swift

It could be both. The brakes also depend on the magnetic strength of the motor. What ESC and motor are you using?

05-14-2026 | 04:36 AM

#51

gigaplex

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Quote:

Originally Posted by OffRoadJunkie

An extremely low resistance on it. Shorting it lowers the resistance.

This works by allowing current to flow through the stator as it acts as a generator, which creates a back EMF that opposes the rotation. The lower the resistance, the higher the current, the bigger the EMF.

05-14-2026 | 07:15 AM

#52

Burl Swift

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Quote:

Originally Posted by OffRoadJunkie

It could be both. The brakes also depend on the magnetic strength of the motor. What ESC and motor are you using?

I'm using the last gen HobbyWing 80a Stock Spec ESC and a Whitz 13.5 off the shelf.

05-14-2026 | 09:59 AM

#53

Mac The Knife

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Quote:

Originally Posted by Burl Swift

I'm using the last gen HobbyWing 80a Stock Spec ESC and a Whitz 13.5 off the shelf.

If you have a programmer, I would try lowering the brake frequency. The lower the frequency the more aggressive the braking.

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05-14-2026 | 10:10 AM

#54

Burl Swift

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Quote:

Originally Posted by Mac The Knife

If you have a programmer, I would try lowering the brake frequency. The lower the frequency the more aggressive the braking.

I'll check to see what its set to when I get home, thanks for the advice

05-14-2026 | 01:41 PM

#55

OffRoadJunkie

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Quote:

Originally Posted by Burl Swift

I'm using the last gen HobbyWing 80a Stock Spec ESC and a Whitz 13.5 off the shelf.

That's a decent setup. The motor is quite a bit old, so the torque might be down. That will affect your brakes. Is anyone else using your same ESC and having good brakes?

05-14-2026 | 06:10 PM

#56

gigaplex

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Quote:

Originally Posted by Burl Swift

I'm using the last gen HobbyWing 80a Stock Spec ESC and a Whitz 13.5 off the shelf.

That ESC is known for having weak brakes and you've put it in a heavy SCT. I'm not surprised it's struggling.

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05-15-2026 | 10:42 AM

#57

Burl Swift

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Quote:

Originally Posted by OffRoadJunkie

That's a decent setup. The motor is quite a bit old, so the torque might be down. That will affect your brakes. Is anyone else using your same ESC and having good brakes?

Nope, I'm the only one in the class that I know of using the "baby" HW. Everyone else is using 160a type ESC's, various brands, I threw the 80a in trying to save weight.

I'll be repowering before the Nat's come locally next year, but it looks like I'll just have to deal with it for the Regionals...