[chucker]

I have a HS 1 Mill 1999 model with cat40 holders that keep getting stuck in the spindle I have put in some new holders and it still happens some times but not always on the same tool and not all the time has anybody had this problem or know of a fix for this other than having the taper reground.

[Geof]

This has been discussed several times for vertical spindles. We have found it sometimes depends on the holders and how hard they are working; some jam frequently some do not, some do it when they are taking heavy cuts for a long time.

Keep everything squeaky clean with a very light film of lube oil; no gunky coolant residue.

A fix that we installed on two machines was an air tank downstream of the machine regulator. If you look at the air pressure gauge during a toolchange the pressure drops dramatically because the airflow is restricted through the regulator. A tank provides a large flow of air when the tool eject cylinder is operated and the pressure drop is much less so the cylinder operates faster and stronger.

[dougtyler]

Another solution is to keep the tapers coated with car wax. It's best to find a brand that has PTFE in it. Just wipe it on and wipe it off. I have used this on 40 taper tools that used a draw bar, instead of a retention knob. Worked great.