Mini Mill Tool Stuck in Spindle

[100]

We had this problem. Used the prybar with very little pressure and the tool pops out. We fixed the problem with a washer .03 between pull studs and the toolholder. The problem on our mill was that the rod that pushes the toolholder out of the spindle was adjusted at the max but it was not quite enough to drop the tool. After putting the washer on all of our toolholders we no longer have the problem and they never stick. We had to play around with the thickness. If the washer is to thick the toolholder will not pull up tight in the the spindle and you can feel the play with your hand. The mill we have is not a haas but it is the same problem.

[Rockyr49]

Got to be careful with that "cure" too. Any lengthening of the retention knob with a washer decreases the amount of drawbar pressure you have. That can cause a tool to come out at a very bad time. Dangerous way to fix the symtom but not cure the problem. Check tool knockout this way. Clamp a tool in the spindle. Check the distance from the flange of the tool to the face of the spindle using calipers or a depth mic. Next Unclamp the tool and hold it in place by hand with the drawbar unclamped. May take 2 people to do this. One to hold the button and one to hold the tool and check the dimension. There should be .015 to .020 difference. In other words .015 to .020 positive tool knockout. If that is there, the tood should release if the spindle taper is good and the machine has proper pressure at the drawbar. Be it air or hydraulic, there needs to be enough pressure to unclamp and still hit the tool hard enough to break the seal. Spindle taper wear is definitley a culprit here.