2.2kw spindle noise

**marbles** · 15-04-2020

Hi,

Have a 2.2kw spindle on my machine. It mills fine but sometimes makes this horrible screeching sound at lower RPM. TBH when I installed it I didnt know to run it at lower rpm to allow the grease time to bed in. Maybe that was the start of the issue?

Here's what it sound like today,not nice!

is this a bearing issue or possibly an electrical issue. Any thoughts or links welcome.

https://youtu.be/JYx9n7kGlSo

**Boyan Silyavski** · 16-04-2020

Wow, sounds like a dead rat inside. Its not difficult to open and change bearings. Do it. Could be bearing or could be sth loose like the spring that pushes the bearings together, who knows. Probably bearing.

**marbles** · 16-04-2020

Sound horrible doesnt it!

I'm going to start by checking my VFD setting today just to eliminate any electrical issue and then look into replacement bearings.

Do you have a source for good replacement bearings?

**JAZZCNC** · 16-04-2020

Throw it away and buy a water-cooled version.!!..

Being serious now that's knackered so at the least, it needs new bearings. However how long do you run this spindle.? if you run for 4+hours at a time continuously or leave a cooling down period between jobs then I would replace it with a WC version because these air-cooled don't have the duty cycle needed to keep them alive. This will happen again and eventually, you'll end up paying more than price of a WC spindle.

**marbles** · 16-04-2020

Interesting point about the duty cycle. Point taken about the water cooling, good to know. Are all the 9kw spindles they put on Chinese units water cooled?

Yeah I frequently run it for more than 4hrs. Not always continuously thought. I recon the issue started not long after I set that machine up milling a marathon 10hr finishing pass on a 2000x600x100mm epoxy tooling board! I'm going to keep going with the air cooling as I do a lot of foam carving and the spindles dont get hot doing those. I'll get a news set of bearings!

**JAZZCNC** · 16-04-2020

Originally Posted by marbles

Interesting point about the duty cycle. Point taken about the water cooling, good to know. Are all the 9kw spindles they put on Chinese units water cooled?

Can't answer that question because I'm not Chinese.!! . . . But that spindle you have there isn't 9Kw. It's a 2.2Kw and whether 9Kw or not they still have a duty cycle and these cheaper units won't cut 10hrs continuously for long before they start feeling the effects. I also very much doubt they will be rated S1 so can cut continous.

**ericks** · 16-04-2020

I bought a very similar motor just to use on my test bench. When i first started it up i noticed the lack of air blowing through the motor, that obviously cause heating even though it was just running without load. Found they installed the fan wrong way around...fixed it and problem solved. Obviously their quality control is not great. Just thought i'd mention it :)

**Boyan Silyavski** · 16-04-2020

Yes, the fan Could it be the fan is broken?

**ericks** · 16-04-2020

Actually, i did not say i think it's the fan :) was just trying to say that these motors don't seem to be very good...their torque for example is not great.