[SheldonB]

Need help trouble shooting tool change knock-out. Has anyone experienced a problem with a decrease in force within the knock-out actuator resulting in tools not releasing. If so, what component in the air supply was the cause? We have increased the stoke but it seems to be lacking force?

[Geof]

Obvious suggestion...check your air pressure. Also check for a sluggish solenoid valve; if the valve opens slowly the air creeps in and the knockout piston does not snap down quickly, the impact is needed for the knockout. If the piston moves slowly at first it takes up the clearance and then just pushes instead of knocking.

I had this problem on a smaller machine and loosened up the solenoid valve by disconnecting the air line leading to the valve and squirting in a bit of transmission fluid.

You use the remedy at your own risk!

[RRL]

Do you have coolant through the tool?

If so, I have seen in the past that coolant can migrate into the clamp spring area. This results in rusted springs, and also when the draw bar is compressed it is not only trying to overcome the springs, but the coolant that may be trapped inside and raises all kinds of havoc with the tool changer!!

RRL