Compressed Air Sound?

[rbcmetalwork]

I have an SV2412 and when the spindle runs I hear a compressed air flowing sound. Does anyone know what this is from?

On a possibly related note, there are 10 small tapped holes on the face of the spindle. One of them has what looks like a set screw in it. What are these holes for?

Thanks

[Geof]

Could be from the spindle lubrication; a lot of machines use an oil mist driven by low pressure air to lube the bearings.

[timlkallam]

I asked sharp that when i got my mini mill they said it helps keep the bearings cool. I turned mine way down I got tired of the air compressor running nonstop.

[rbcmetalwork]

How and where do you turn it down? I know what you mean about the air compressor running non-stop. I ran a long program today and the air compressor kept going and going...

[SteveinAZ]

Be careful adjusting the air blow...it could be an air-oil mister for the spindle bearings or an air curtain around the spindle face to keep coolant and contaminants out. Either way, call up Sharp and ask them, if misadjusted you may loose the spindle bearings.

The screws on the face of the spindle are for balancing. When the spindle is built and tested either by the factory or aftermarket rebuilder, they balance it using set screws in these holes. Depending on the spindle, there may be a bunch at the other end too.

Steve