"Charles Spitzer" wrote in message
...

maybe because it won't burn. if the round one gets a little bit stuck or
doesn't rotate at the same speed, then it might burn the laminate?

But which is better a burn or if the square one gets a little bit stick or
does not allow the bit to rotate inside the square guide bearing it may dent
and bang up the laminate. Actually my round bearing stays clogged up with
glue and does not always spin. No burning. I suspect because it does not
stay in one spot long and has a slick surface.