[Geof]

This fairly common especially after a bunch of heavy machining; the tool seems to settle tighter in the taper.

The carousel does not pull the tool out of the taper there is an air cylinder at the top of the spindle that is supposed to release the drawbar and knock the tool out as the spindle lifts up during a toolchange. Sometimes when the tool is tight the knock out is not enough and the little bit of extra force from the carousle lfting is enough to release it but really it should release just from the knock out.

You can reduce the sticking by making sure you keep the spindle taper and tool holders nice and clean; don't let a film of dried out coolant form keep them well wiped with just a thin film of light machine oil.

If you keep track of what holders stick the most you can maybe use these ones for only light cutting; we have found there is quite a variation between holders even from the same manufacturer.

Another way to get a better release is to install a reserve air tank on the low pressure side of the regulator on the machine. The machine pressure should be 85 psi but when the tool changer operates it often drops to around 65 psi because air cannot flow through the regulator fast enough and the knock out cylinder moves slowly. A reservoir tank on the 85 psi side keeps the pressure up.