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magnum
10-06-2005, 10:08 PM
I have not broken a collet on my Bridgeport in 19 years - this week I broke 2 1/4" collets in the Colombo - why? Anyone else have this problem? Am I over tightening? Been cleaning between changes with a toothbrush and air. Also getting a grinding noise intermittently in the 15000 rpm area. Is this normal? Only had a few weeks on this machine.
TIA

Brady Watson
10-06-2005, 11:23 PM
Barry,
Make sure that the spring collet is correctly seated in the collet nut. You have to press down and turn 90 for it to be properly snapped in and seated. Then thread the nut/collet assembly onto the spindle...then insert your tool and tighten. The spring collet should appear to be even with the bottom ring of the nut.

You should not be getting a grinding noise at any RPM...However you may be hearing vibration coming from the cooling fan or other metal parts near the spindle causing resonance & vibration.

-Brady

magnum
10-07-2005, 01:03 AM
This is not how I have been doing it. Will try to put the collet in first and then put the nut on. The nut never seems to go on easily - hard to keep all parts together and get the thread going - thought the Italians were crazy here....

Brady Watson
10-07-2005, 09:47 AM
Barry,
If you snap the collet into the nut, it should not be difficult to screw on to the spindle correctly. Hold the shaft with one hand and spin the nut on.

-Brady