CNC Bits

CNC BITS

By: Josh Rucinski

A primer of your Bit choices in the DFL.

        The upcut bit.  This bit gives very good finish cuts with the surface of the material.  It should be used for profile cuts and highly detailed scoring.  The downside is that this bit is more expensive, and more easily damaged then other bits.

        The Mill End bit.  This bit gives good all around cutting, but the edges of the cut may need light sanding.  This bit gives the best performance as a pocket cutting bit.  This bit is best at creating flat pockets cut into wood.  It is analogous to a butt shoulder cut with a chisel when creating a pocket for a hinge.

The V-groove bit.  This bit has a 45 degree miter to form the "v" shape.  This bit allows precision mitered edges in woodwork.  The woodworker must take into account the very small varience due to the inputted thickness of the wood and the actual thickness of the wood.  It will be very slightly different because to completely cut through the wood, it is best to input a number at least 1/100th of an inch larger.  Otherwise there is a risk of being left with an thin skin of wood due to the varience that sheet goods have in tolerances.  The skin left over is referred to an 'onion skin' in CNC lingo.

        The Ball end bit.  This bit is used to create 3D models.  The spinning bit creates a half circle profile cutter head.  The amount of offset in each pass determines the resolution of the model and the time it will take to cut.  Models with very high resolution will take much longer to cut.

        The levelling bit.  This is a speciality bit that is used to clearcut large swatches of material in one pass.  The shape is basically a cylinder with carbide cutting edges on the perimeter of the bit. This bit is usually a poor performer for most applications.  It is used to level the CNC table periodically, and it could be used to cut an entire piece of material down.  For instance, if you needed a piece of material exactly 1/2 inch thick or 0.500 and your material was 0.625, the levelling bit would cut down the board the fastest.