Hello,

I have a problem with an old Dynamyte EM-3116 mill. The collet is not locking properly to the quill when tightened with compressed air. The collet seems to lock at least almost properly when tightened at first. However, when the spindle is turned on, the collet drops down slightly for an unknown reason and the grip becomes loose. When the spindle is stopped the collet stays on the downward position and is not held tight.

What could be the issue?

Background: The collet holding screw was changed, although this is likely unrelated.