Use wooden jig to stop hole saw sliding around at first, until you get a small groove of 1mm Add water regularly to keep the drill bit cool Start with a slow & steady speed Not much pressure, sometimes just the weight of the drill You’re actually GRINDING, not cutting – so go slowly Replace water regularly You can remove the jog once you’re in even 1mm or so More water . . . I had added duct tape underneath so the cutting won’t fall and smash Always slowly, especially at the end The finished product . . .