JT continues his series on Building and Programming the Fabulous Fabio “Arduino-Compatible” Controller Board:
Setting Z-axis milling depth with conical engraving bits.
The Fabio Arduino clone PCB was milled into .062” (1/16”) FR4 PCB material with a 1oz. copper cladding (weight of copper is 1 ounce per square foot). The CNC engraver / CNC Router was fitted with a 45 degree engraving bit from Think & Tinker LTD. I picked this bit so I could adjust the width of the cut by specifying the depth of cut and still make some narrow cuts. If you do the math (Geometry, actually), you come up with a formula that tells you how deep to make a cut for a desired cut width and tool tip included angle. To make things easy for you (and me) I developed a spreadsheet for various engraving bit included tip angles as shown below: Continue reading »
