Yeah, you've got to go over metal with really coarse paper to get a good noise out of a sander. Unless it's one of those massive bench ones and you can get a bit of plastic or something to wobble about the horizontal just above it and catch on the belt, spring back up and drop down and catch again.
That was a memory from year 10 plastics, I totally didn't realise back then that noise was one of those things you could be into.
Currently I'm listening to a preview of an upcoming release by a band (guy?) called
drawing voices. That link goes to the preview, that's really all I know about the band/album. So far it seems like interesting yet accessible noise that doesn't do too much (hardly any actually) of that one loud texture for a short while, abrupt cut to another, suddenly into another etc. If I run into this on a shelf somewhere it's a very likely impulse buy.