More Lucas PTE Tips

A commonly seen problem with the Lucas PTE system is a foreshortening of the travel length of the collet - resulting in an inability to insert or remove tooling from the spindle of the machine.

While this symptom may indicate a serious PTE problem for which the system needs to be returned to the factory for a complete rebuild, it may also indicate a minor and easy to repair problem.  Here is how to test for this problem.

1. Place the PTE system into Clamp.
2. Feed the spindle a small amount OUT of the head.
3. Place a dial indicator on the tabletop with the indicator plunger against the end of the spindle.
4. Zero the indicator.
5. Place the PTE system into Eject.
6. Place the PTE system into clamp
7. Read the dial indicator.
    

A reading of more than a few thousandths indicates that the bearing assembly at the rear end of the spindle that mounts the PTE ejection cylinder to the spindle has become loose.  Simply tightening the nut on the rear end of the spindle will allow the PTE system to function correctly again, however, there is actually a completely different problem present that caused the nut to become loosened.

A little investigation will show that there is no lubrication to the bearings that are 'set' by the nut.  Running the machine without correcting the underlying lubrication problem will result in the nut becoming loose again and may result in bearing failure.