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Which ESCs keep brake on indefinitely ?

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Old 08-15-2012, 01:28 PM
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Bobhend
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Default Which ESCs keep brake on indefinitely ?

I was out flying my Phoenix 2000 today and the motor continued to windmill. The BRAKE function is turned on, but does not stay on, it just brakes for a few seconds. This ESC is one of Hobbyking's that came with the plane. Can anyone verify that a quality brand ESC like Castle or Electrifly has a constant always-on brake function ?

For what it's worth, this 2 m glider is a great flying plane but I had to replace the motor and re-engineer the motor mount. Oh yeah, and the brake does not work, but hey $ 80 receiver ready. I got under a growing cumulous cloud and had lift continuously even with the prop windmilling away.
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Old 08-15-2012, 03:00 PM
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jshelton999
 
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Default RE: Which ESCs keep brake on indefinitely ?

Castle does. So does Jeti. Most every ESC supports hard braking which is what you want.

Jim
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Old 08-15-2012, 03:52 PM
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Default RE: Which ESCs keep brake on indefinitely ?

Please note there is no always on braking. Hard braking will help assure that a folding prop will fold or that a regular prop will stop but it won't prevent the prop from windmilling again once the braking action is done. No ESC applies a full time brake.
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Old 08-15-2012, 05:24 PM
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Default RE: Which ESCs keep brake on indefinitely ?

I suspect continuous hard breaking would be a consistent high drain on your battery. Anybody know how much current it draws when it’s on?
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Old 08-15-2012, 05:40 PM
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Bobhend
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Default RE: Which ESCs keep brake on indefinitely ?

No power would be required if the windings are shorted to each other. Take a motor [disconnected from ESC etc.] and short two or all three wires together and try to turn it. You can rotate it but it will not spin.
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Old 08-15-2012, 06:05 PM
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Default RE: Which ESCs keep brake on indefinitely ?

Yes but that insen't the actual mechanism used in operation, is it? I thought the back EMF from the spinning prop was used to supply the breaking effort.
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Old 08-15-2012, 07:45 PM
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Bobhend
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Default RE: Which ESCs keep brake on indefinitely ?

I just found a Turnigy 25A "Basic" ESC, cost $ 11 I think. I installed it in the Phoenix. Anyway, it provides permanent braking action. My problem with the one that came with the Phoenix is that it has no name or markings and would not respond to programming "throttle stick" instructions for Turnigy, Electrify or Thunderbird. I am going to wildly speculate that 'all' ESCs short the motor coils indefinitely when receiving a low throttle signal from the transmitter. With the transmitter off there is no braking. I don'y think it is using much power for braking, however I hope to hear from someone that is sure.
The Prius uses back EMF to recapture the braking energy but our brushless ESCs can only brake, not regeneration.
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Old 08-15-2012, 10:45 PM
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Default RE: Which ESCs keep brake on indefinitely ?

If you're not using a folding prop then it's going to windmill to some extent even if the brake is on all the time. An "always on" brake is simply one which shorts out one or more of the "phase windings" on a brushless motor. And at the sort of low RPM you get it can still windmill at anything other than slow to moderate flying speeds. It just won't windmill as fast as it would otherwise.
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Old 08-16-2012, 09:52 AM
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Default RE: Which ESCs keep brake on indefinitely ?

I had the Phoenix 2000 out today and the prop was folding back perfectly. This is a great thermal flyer from Hobbyking for $ 80 receiver ready.
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