Some customers have been getting good results with the Drill Doctor. Others not so good. Most of my customers just throw away anything under 1/4".
Your rake is built into the drill, so you really can't change that by any means other than trying different brands of drills. I recommend a good quality 'brite' finish drill for aluminum. A parabolic cobalt drill has been our savior in copper. Keep the RPM's down and the feed up. The chip needs to be thick enough that it takes all the heat out of the hole for you. The end relief for both mat'l should be 11 - 12 degrees.
__________________
Where Your Quality Counts!
www.toolgrinder.com
durkee@toolgrinder.com |