So trying to put a keyhole in purpleheart is tricky. With a simple plunge and traverse the bottom, sides, top and keyhole portion of the bit constantly stays in contact with the wood. This leads to lots and smoke and burning of the wood and bit. A friend at work help me make a program that moves in a spiral in the vertical and horizontal movements. As you can seen there was zero burning on the wood.
The G Code can be downloaded with the link below.
https://app.box.com/s/ja26gy1keg3w3cp5b2crqkyhmh4pcyo7
The bit i used is the following
Enjoy
