Originally Posted by
syscore
I was drilling 0.201" (#7) through holes in 1" 6061 stock, and it seems that no matter how hard I tighten the (tormach) keyed chuck, the bit seems to get push up into the chuck the deeper the hole. I switched to a collet and it seems to work fine. Is that a common experience? I was drilling at 3000 RPM, 12 IPM, 0.2" Peck. I started at 4000 RPM, 15 IPM, 0.1" Rapid Peck, and I think that would have been fine, if the bit didn't keep working its way up in the chuck. I didn't try the more aggressive drilling yet with the collet setup. All of this is with flood coolant. Holes less than 0.5" have never been a problem with the keyed chuck. I also tried the keyless chuck awhile back, and concluded that is maybe ok for plastic or wood, but not metal.
Bob