>> >>> I have a craftsman 10" compound miter saw and the brake no longer works.
>>> Anyone else experienced this problem or know of a fix without going to
>>> Sears service center for the "$35.00 look & see"
>>>
>>> Dave
>>
>> Does any one know how long reverse polarity is applied to the motor to brake the blade?
Momentary or constant? if momentary I assume there is a relay or capacitor in the trigger that applies the voltage.
> No reverse polarity. They short the motor into a resistor and the
> resistor dissipates the back-EMF, essentially turning the motor into a
> generator driving a resistor.
>
Almost all of these work with the motor turned into a generator when the trigger switch is 'off' (effectively shorting the motor). The most common fault, by far, is the trigger switch has succumbed to dust intrusion (easily fixed with a blast of compressed air). Sometimes the brushes get worn to the point that they no longer seat properly and cause the same braking problems.
-BR