Proper assembly of the collet, nut, and tooling is critical to successful milling. Failure to secure the collet correctly will lead to poor cutting quality and oversized holes. It could also possibly result in a catastrophic failure with damage to the collet, nut, tool, workpiece, spindle, and CNC machine components.
1. Make sure the collet is properly seated into the collet nut. The collet should snap into the collet nut when turned at a 45-degree angle so that the collet and nut do not come apart. Slide the tool into the collet-nut assembly. Thread the tool-collet-nut assembly onto the spindle.
2. Push the tool all the way into the spindle while threading the nut onto the spindle by hand as far as you can, then tighten the collet nut using wrenches to ensure that the tool does not come out while milling.