I recently made some corian pens. What I did was keep the drillpress in the mid range for speed. I cut the peices a little long so if there was any chip out it wouldn't matter, and pulled back often to clear the chips (or what every you want to call the long plastic curls).

Just a regular bullet or brad point, both have worked. Sounds like yours might be getting too hot. Slow the speed down a little (though others have said to speed it up, I would try both and see which works best) and clear the chips frequently, that will allow it to cool a bit and when the chips/dust etc pack in there, the bit makes a lot more heat, causing it to crack. Same thing happens with ebony, blackwood etc.

I tend to go mid speed on the press (drill speed). Rate of decent is a whole 'nother matter.  I go what the blank will take, and that depends on size, species and drill speed. But...slow down as I am about to exit, that will help prevent chip out. Also, keeping it a little long helps as well, as any chip out is in the "extra." I cannot overemphasize releasing the chips, it will save many a blank.  Cristensen's (sp?) book is very good for pen turning and I think he just came out with a video.

I saw the video I think you are referring too, the one from pennstate. He does an adequate job, but I do suggest the aformentioned book, it made a world of difference. Also, the advise from Smokey and Cfuller (among others) has been outstanding.

I asked one of my tax clients who does custom counter tops, and he said that there is a special drill bit for Corian.  I remembered needing one for when I was drilling PlexiGlass, he said it is the same one.

JimQ

Thanks everyone for the suggestions.  I have been using a bullet bit and backing of oak scrap.  I'll try slowing down the drill press and my feed speed and let you know if it solves my problem.  Thanks again.