Electric drill whining noise

rob77 · 10 Jun 2015 at 17:31

Hi Guys

Sorry if this is in the wrong part of the forum but didn't know where else to ask.

I have just bought a li-ion cordless drill but noticed a whining noise coming from it if I press the trigger gently. When it is running with the trigger fully pressed down it seems okay. I just wondered if this was normal and just how the motor works?

Cheers

Skidder · 10 Jun 2015 at 17:34

Normal

Brutal biff · 10 Jun 2015 at 17:35

It's fine it's normal it's only whining because of the gears inside

rob77 · 10 Jun 2015 at 17:37

Thanks guys

Its almost like a constant beep. Then as the driver starts rotating if I press it a little more it goes away.

NickK · 10 Jun 2015 at 17:45

This thread disappoints with the lack of GD responses.. The garden etc forum would answer - but you may end up with a new set of drills and an SDS too!

The way that most modern drills work is to control the power using rapid switching (called pulse width modulation, PWM) that is more efficient than using a resistor. The down side with PWM is that it can make varying whiney noises as the pulse length changes. Especially on cheaper implementations of it.

With big high speed PWM (i.e. direct class D audio amps) the switching is so fast you don't hear them but the switching has to be shielded as it gives of microwaves!

snapdragon69 · 10 Jun 2015 at 17:50

It's the speed controllers PWM oscillator that controls the speed. It emits a beep at the frequency it operates and the torque increases with the width of the pulse.

Cosimo · 10 Jun 2015 at 17:52

Came in expecting some gory details of drilling into human flesh.

rob77 · 10 Jun 2015 at 17:55

Thanks for all the responses

Now I know it is normal and have ordered a wera bit set to go with it I'll be having a play this weekend. Nothing at the moment to fix or make but I'm sure I'll find something!

ZG002 · 10 Jun 2015 at 20:17

rob77 said:
Thanks for all the responses

Now I know it is normal and have ordered a wera bit set to go with it I'll be having a play this weekend. Nothing at the moment to fix or make but I'm sure I'll find something!

That's the spirit lol

Hades · 10 Jun 2015 at 20:24

Buy hammer.
Break stuff.
Use drill to fix it.
Profit...

Participant · 10 Jun 2015 at 20:35

Are you sure it's not your wife?

rob77 · 10 Jun 2015 at 20:51

Participant said:
Are you sure it's not your wife?

Haha her as well. Is that normal??

arknor · 10 Jun 2015 at 21:01

rob77 said:
Thanks guys

Its almost like a constant beep. Then as the driver starts rotating if I press it a little more it goes away.

speed controller expensive rc cars do the same thing

doofer · 10 Jun 2015 at 21:07

I have a hammer and it makes these loud banging noises but only whenever I hit anything hard with it.