Hello, I own a Bridgeport Boss 5, with what I believe is a Series 2J head. It has the Erickson QC30 spindle. It works fine when taking very light cuts, but today I was taking a (fairly conservative cut) with a 1/2" Carbide End Mill. It was all going great until the tool holder fell out of the spindle suddenly, destroying my work piece and tool.

This has happened 3 or 4 times with this machine now. It has a solid spindle with no drawbar or hole for one.

Has anyone run into this issue before? What can I do to prevent this? The spindle nut was incredibly tight.