Reply by spunwood

I had this problem. The big thing is to make sure that the chisel and auger bit height relationship is right on. Try this video:

http://blip.tv/the-wood-whisperer/episode-5334237

With all that said…I still haven’t got my craftsman mortiser to just right. So I am selling it and going to learn to do it by hand.

-- I came, I was conquered, I was born again. ἵνα ὦσιν ἓν