Thread: Brushless Tools Noisy?

I recently bought a few of the Ozito 18v power tools and they are pretty quiet and yet still have plenty of grunt, I am not sure if they are brushless or not But they come with a 5 year warranty so I assume that they are brushless to last this long.

I managed to try my theory out at Bunnings as they had a charged up Ryobi battery available which I tried in some drill machines, angle grinders and impact drivers and the brush-less ones are a little noisier. The impact driver hardly noticeable but then it wasn't under load, and I think some of the noise is on run down, something to do with braking perhaps.

I just bought the AEG twin pack, and they don’t seem to be any noisier than anything else I’ve used.

I've had my Ryobi One+ non hammer drill now for a while. I assumed that the gear whine noise was either the gearbox and or clutch/brake system.
I recently got their impact driver and it's just a teeny bit quieter than the drill.

I have top of the range Makita gear and find it fine, no extra noise and finding the battery life fantastic compared to my old Panasonic gear, although to be fair I am comparing 3.3ah to 5ah.

But who really cares?
Surely the sound of the rattle hammer in a rattle gun drowns out everything else.

I had an old Ryobi 18V drill ( about 15 years) which died a couple of years ago and I replaced with a new one and I didn't really notice any difference, though I was not looking for one.

Regards Philip A

Brushed DC motors are pretty quiet when they run unloaded by themselves. Most of the noise you will hear from your old drill will be the gear box.

The term "Brushless DC motor" I reckon is a bit misleading. The motor essentially runs on AC. There is an inverter that turns the DC into AC (well sort of AC at 18 volts), it can also vary the frequency of the AC, which gives the speed control.
The inverter itself will make a bit of noise, usually a high pitched squeal, but the motor when run unloaded will make a lot more noise than the old Brushed motors, that's because the frequency (speed) the inverter puts out changes to keep up with the changes in motor speed, but because the motor is unloaded the speed "bounces" around a bit, the inverter chases the "bouncing", which makes the motor bounce a bit more, etc etc. The bouncing creates the noise. Even in your low tech drill it will be doing this correction several hundred to a thousand times per second. Once loaded the bouncing in the motor speed is reduced a lot, so the whole thing stops chasing itself.

When you load the motor up it should quieten down a bit but you probably wont notice it as the noise from the gbox will start to ramp up.

Apologies for the boring detail, slow day at work.

Cheers Glen

LOVE my Milwaukee 18 volt Fuel tools. Not as noisy as my old Makita stuff, although I now wear hearing aids so what would I know?