Did you know that the C12 has overload protection?

[dltflt]

I did not see it in the literature, but I was drilling a 35mm hole for hinges and pushed a little to hard and beeped and shut off.  I relesed the trigger then started drilling again.  Is that normal or is there an issue with the drill.

 

[Eli]

I don't have one so I couldn't swear to it, but maybe it has something to do with the charge on the battery? Otherwise overload is handled by the clutch setting? Only used one a few times, but I remember that beep I think.

 

[Scott W.]

I was using mine today with a 1.5"  bit & had the same experience It beeps & stops. Let up on the trigger & it will start again.

Full bat. right off the charger

There must be something "in there"

Scott W.

 

[bruegf]

C12 has circuitry to protect both the motor and the battery.
http://www.festoolusa.com/Web_files/C12_technical_review.pdf

 

[dltflt]

Thanks for the link Bruegf.  That was great information.

 

[Spike]

It is an awesome drill!! I bought one 2 weeks ago, and yesterday bought another to minimize change over time. When I first saw and handled the C 12 in the store I backed away because I simply didn't understand it's design.

After a short couple of weeks, it is by far the best drill I've ever used. Brilliant in a word.

 

[Dan Lyke]

... pushed a little to hard and beeped and shut off.  I relesed the trigger then started drilling again.

So as a sometimes electronics designer, I can tell you that it's the same "low voltage" detection that occurs when you run out the battery, just that in this case the low voltage is happening because you're drawing too much power at one time from the battery. Remembering that the voltage in between two series resistors is the total voltage times the resistor between 0 and the measurement point and the total resistance of the two resistors, and that the battery has an internal resistance, if you make the resistance between 0 and the measurement point really small (by loading the motor heavily), the voltage drops and the drill detects an undervoltage situation.

More than you wanted to know...

I think I remember that it also has a motor temperature sensor, but that's not the same thing.

 

[LaserGecko]

In short, if you're engaging the clutch, it will shutdown within a half a rotation with a "beep". If there's no clutch ratcheting, then it's a low battery warning.

BEST DRILL EVER. Man, my BattleBot building friend was amazed that someone finally put a brushless motor in a drill.