Removing the electric break from a cordless drill?

Electric brake? Those I've seen with that function are mechanical.

Would the owner of this device,

please tell us what drill you are using that has an electric brake?

He's using drill bits that create excess torque. :-)

Rene

My pleasure.

Features and details:

Owner's manual:

Parts breakdown:

They don't even explain how to remove the chuck, so it's not exactly technical.

A so-called electric brake is a common feature of modern drills. I guess the way it works is bleeding off the electricity generated when the rotor is spinning down. Not knowing much about electronics basics, I guess if there were no place for the current to flow, there would be no braking effect. Then again, maybe it's just the magnet that causes the braking effect. You tell me.

I'm planning to use the drill as a modular scooter motor and I'm concerned that the massive reverse electric pressure when coasting down a hill will cause the controller/switch to overheat. If that's not true, please disregard.

Thanks.

Its called 'friction' - the force in nature that causes everything to stop if you dont keep supplying power to it.

Luhan

"Shift-Lock? drive system quickly shifts from "drill" to "driver" mode"

That makes sense, but I doubt the brake is electric. Many devices have a mechanical brake so you can use it as a manual screwdriver.

Ive got an old black and decker screwdriver/drill, as well as the trigger there is a switch for fwd, reverse and stop - wich puts a short accross the motor.

However the reduction geearing is so great that it is close to becoming imposible to turn due to friction anyway, ... for a certain reduction ratio there is a level of friction that will make it imposible to back drive it,

To make the drill light a small but high speed motor is used with lots of reduction to get the torque.

I would suggest the reduction used in a hand held drill would make it unsuitable for a scooter.

Colin =^.^=

The parts breakdown kind of shows that the chuck can not be removed.

I see in the parts breakdown that the Var/Rev Switch (8) has some sort of power FET screwed into the FET Spacer (22) that is screwed into the Yoke (16).

I see on page 5 of the owners manual "electric break", but its not very clear what that means.

I don't think I have ever seen this "common feature" in the drill display at Lowes or Home Depot.

I will start looking now, as I have not purchased a drill in years.

Good Luck

donald

The amount of effort to guess what this "electric brake" does, could be spent on setting up a test fixture to test this out.

Measuring the amount of current thru the motor at some load, then releasing the trigger would show a reverse of current into the motor. That amount of current would be directly proportional to the amount of breaking.

I agree that the free-wheeling current of the motor windings will feedback into the FET control.

I am sure makita did not design this drill for the strange uses people will find to use it for. But, I am sure they did design it for some safty reason. And I am sure, freewheeling was not one of them.

Testing is the only of knowing.

Good Luck

donald

Get another motor and build a peice of electronics that fits. I once equipped a skateboard with two motors, one for eack back wheel. While it was a bit fun, it wasn't great fun with the 20 pound on nicads underneath the board. The electronics was a 4-quadrant switcher for each motor.

Rene

I doubt that it will coast at all.

My DeWalt cordless appears to have an electric brake. I would have thought it to be mechanical, but I note that the brushes spark when I let go of the trigger.

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I'm quite sure it has a mechanical break that lock its when no powered, othervise it would be difficult to tighten the chuck.

-Lasse

...

Gear selection, a single sleeve ratcheting chuck (not to be confused with the two-handed "keyless" crap), and being able to lock out the clutch with a switch instead of having to rotate all the way around to the drill setting, and NiMH or Li-Ion batteries are all significant improvements from my cheapo Skil 12 V model from five years ago. Unfortunately, Makita's 18 V model is heavy.

Thanks for the follow-up confirming Roger Hamlett's original warning about the free-wheeling current of the motor windings feeding back into the FET control. If I can't find an electrical solution, I might do a mechanical solution. Whatever.

Sure. I built mine almost 20 years ago.

Rene

Maybe I will run the drill and measure the controller's temperature, then connect the other end of a 1/4" steel rod to another drill to spin the otherwise unpowered drill and see if the controller overheats.

Thanks.