Hydraulic/Air Chuck?

[Hellbringer]

Hi i was woundering if someone could shead some light on how a computer controled hydraulic/air chuck works. also i see that some of the cnc lathes use a collet disign to grip the stock, the biggest collet i can find is 1.25" is that the bigges stock you can do with a chuch system?

thanks for you help in advance
Mike

[philserveng]

absolutely not, collet chucks can be very large diameters. The difference is that chucks can grip more firmly and are more suited to billet work (hand loaded). Collets are more suited to bar work where a barfeeder is used.

They work in similar ways, except that a collet chuck is pushed by the draw tube and the 3 jaw chuck pulls the draw tube to clamp the work. Both systems need valves to actuate the stroke of the draw tube and both need switches to monitor the function. See M10/ M11 codes for this function.