When choosing CNC tools, there are plenty of options to consider. CNC routers need bits. The bits determine the type of carving you can do, how fast you move through the material, and how your finished design looks. The bits come with cutting edges that push down or pull up, have shaped or square edges, and are available in different diameters. There are some key features to consider when choosing CNC bits and CNC tools.
The Bit Shape Suited for the Project
If you are making straight cuts into plywood then you want to get a quality spiral cutting endmill. If you are carving large 3D contours then you need a ball-nose bit that is sized for the level of detail in your model. If you are doing detailed sign making or lettering, consider a v bit. This will also be the only way to have a sharp, grooved bottom on the inside of Roman numerals. If you are in charge of maintaining the spoil board on the CNC router or flattening large boards then you need a spoil board cutter. These are designed to give you a smooth, flat finish.
Choose a Bit Made for the Material
When searching for CNC tools, you need to find the right one for the material you are using. Bits for hardware are made to leave a clean edge. Bits for laminates and plywood are made to not crush the outer veneer layers. Bits for plastics help avoid any excessive melting. Many bits can be used for multiple applications so you may not need to get many different kinds right away if you are still in the prototyping stage of the project.
Choose the Strongest Bit You Can
An important thing to remember when you are picking a bit is that stout, short bits produce a cleaner cut. If you have a long bit, it invites stool vibration and deflection. These conditions make for rougher looking cuts and also shorten your tool life.
Balance the Need for Speed with Edge Finish
The bit design you pick will be made to either cut smooth or fast. If you need to cut a large amount of material quickly then you need a more aggressive bit that is pushed through the material faster. If you are making furniture and you don’t want to spend the day sanding then you want to choose one that is designed to leave a smooth finish. The more cutting edges a bit has, the finer the cut will be.
Choose the Correct Bit Direction
Spiral bits can be used for lots of applications and is a multipurpose tool. One of the big decisions you need to make when choosing your bit is cut direction. Your choice will be between downcut, uncut, and compression.