Over the last couple of weeks, my mill has been making a weird noise, but I just couldn't pin down where it was coming from.
It was definitely bearing related and sounded as though a tiny bit of swarf had got in there to cause the noise. Sort of like a sea shore whoosing noise, small waves breaking on a beach, that only happened every now and again.
Anyway, as visitors came and went, I asked them to listen and see if they could come up with a location. I had already disconnected and run up the motor to rule that out, so it had to be somewhere on the spindle or quill.
Eventually from the suggestions and elimination, it boiled down to one bearing, about the easiest one on the machine to change, and about the only one where swarf could have penetrated.
This is where the noise was coming from. This is the spindle brake area, and the bearing is under that slotted nut at the middle.
Undid six cap screws, prised off the brake casting, undid the nut, replaced bearing, and assembled in the reverse order. Ten minutes round trip.

This was the culprit, shown with a new bearing. The replacement one is already installed, and this is a spare, just in case it happens again.
The bearings cost less than 3 squid each off ebay.

I will now make a plastic cover to sit over that area, and hopefully the dreaded swarf won't get in again.
Quiet time Bogs