Hi
Yesterday I was messing about learning to use an edge finder, so was not actually doing any cutting, but the spindle was doing around 1500 rpm. I noticed after about 6 or 7 minutes that the chuck felt warm despite no cutting taking place, and when I felt the body of the mill it was very warm to the touch from the drill chuck all the way to the top of the plastic motor cover.
Does this sound par for the course? With no load I would expect a smaller current draw and so less heat. There is a ton of oil inside the head, so much so that occasionally a little drips out on the table. It is an open design and you can just squirt the oil onto the gears.
The mill is a WM18, and I have had it since May. I had some electrical problems with it which were resolved with a new controller board, but given past performance I want to ensure this level of heat is to be expected.