I've just graduated to CNC, having retrofitted a cheap Rong Fu machine with motors, ballscrews, etc. And I'm getting quite familiar with Gcode and Mach3. It took a while to figure out that the Taiwan inch for the Z axis is only a metric approximate of a real inch, but I digress
In the part i'm building, I need to first put a 3" diameter hole in the middle of a 1" thick bar of aluminum. Before the CNC I would have chucked it up in the Lathe and bored it out, but now i've got to take a new approach, and since there are so many ways to program a hole I thought I'd ask this forum.
First off, it needs to be done with a 1/2" flat endmill.
The first time I programmed it, I would cut down 1/8" and make little circles in the center going progressivley outward continuously cutting. This worked well for cutting, but the chips would fall into my pocket.
Now i'm making a series of holes that go all the way through, starting small and slowly widening the hole, cutting only with the edge of the mill. This takes much longer.
I'm now wondering if I should cut a series of holes like I am now, but in a helical motion instead of in stair steps. I'm a little nervous about using the bottom of the endmill to cut down at the same time as around, but it would be a big timesaver. I'm curious how this would affect tool wear, since I'm using the bottom of the same bit to face off tops of the part in a finish pass.
Any thoughts would be appreciate. Thanks!
Stewart