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Re: Drilling (geometry change)
Re: Drilling (geometry change) -- NDR	Post Reply	Top of thread	Forum

Posted by: randykimball ® 01/30/2006, 18:45:25 Author Profile eMail author Edit

The amount of rake on the flute points determins what shape and where the chips try to go. The type tip grind (in the center at the web)determins how much force it takes to push the drill into the work, but if it gets too thin on the end it will break too easily. This is called "thining the web". Remember, at the exact center of the drill there is close to zero surface footage, so the way a drill cuts in the center is completely different than the way it cuts farther out near the flute edges. If drilling through thin materials, one can grind the faces of the web vertical for a few thousands or as far as the flute edge sprial to prevent the drill from grabbing and "screwing" itself through the work. The configuration of grind can determin whether the drill hunts center or strays off, at the expense of effeciency. Chip breaking configurations can be ground into the flute face to cause chips to roll up or break, or even to stream up through the hole. There are many ways and configurations to grind a drill point. Different grinds work best in different materials, as well as different depths. /←randy→/ The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them. Modified by randykimball at Mon, Jan 30, 2006, 23:14:21

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