ER Collet Connundrum

This is an article, written by Dan Murphy, that originally appeared in our June newsletter, The Swiss Advantage. More readers clicked through to read it that any previous article. For that alone, I thought it was worth posting.

Given the stringy nature of the chips from cutting 316, plus the cycle time penalty of single point threading, we decided to thread mill. When the job was set up, the thread mill chattered horribly.....The ER collet was technically the right size. The “inch” size shank of the tool was less than 1mm smaller than the ER collet nominal size. The collet nut was tightened down plenty tight. Tight enough where there really should be no question that it was holding onto the shank...more.