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Old Jan 01, 2010, 11:55 AM
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Finding Motor Problem

The trouble is a pulsing motor (like a gas engine cutting out) at almost WOT. Is there a way to determine whether the esc or motor is causing the problem...without having to swap out parts?

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Old Jan 01, 2010, 12:01 PM
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It's likely neither the ESC or motor but rather the battery being unable to hold sufficient voltage under load and the ESC is hitting soft cut.

Can be verified with a wattmeter.

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Old Jan 01, 2010, 12:03 PM
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Could be pulling to many amps. The battery can't hold up. Loose connection, bad solder joints, too small of wires, esc timing, bent shaft. Got to look it all over well.
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Old Jan 01, 2010, 04:51 PM
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a few potential candidates rear their head here.

1/ does your antenna pass close to the motor?
2/ are your motor's brushes in good condition and not causing the motor to spark?
3/ are you suppressed sufficiently
4/ vibration causing connections to fail
5/ is the esc's rx lead in good shape, no broken wires, is it plugged in properly at the rx?

my primary suspect would be arcing from the motor affecting the signal if its brushed motor, check where you run the rx antenna
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Old Jan 02, 2010, 12:41 PM
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I've had a damaged Rx crystal cause strange things after a bad crash. It caused surging throttle, then a snaproll right over my head during a low pass !
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Old Jan 02, 2010, 01:39 PM
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Many ESCs pulse the motor when they're approaching lvc, to warn you that it's time to land. As mrforsyth has suggested, battery voltage may be dropping to lvc and thus causing the ESC to go into pulsing mode.

Possible reasons include battery too small for the amps that are being demanded, battery getting too old, or some fault in the power wiring or connectors. A wattmeter will show you how the voltage drops as the amps increase.

What motor/battery/prop are you using?
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