The 1/8" end mills seem to lack a flat spot. On the shank of end mills there is usually a flat spot so that the set screw that holds the end mill in its holder can gets a solid purchase. I have been struggling with the set screws failing to hold down on the perfectly round and very smooth shanks. As feed rates increased, vibration was loosening the end mills.
After reading discussions on this online, I used my grinder to cut a little notch in an appropriate place on the shank. It seems to have solved that problem.
Perhaps you should use an end mill to mill a flat spot on your end mills.
ReplyDeleteI thought very seriously of that but holding an endmill securely in a vise sounded like an opportunity to break a mill. The next time I break one, I will try that on the scrap.
Delete