There are hundreds of possible bits available? How to know where to begin.
The reason there are hundreds of possible bits is that there is no single perfect bit for all job and materials
Start simple and ask yourself two basic questions:
1. What material am I usually going to be cutting? (plywood, MDF, solid hardwoods, foam, plastic, metal, etc.)
2. What kind of designs: 3D, V-carving, cutting out parts? i.e. are you usually cutting all the way through the material or just carving on the material?You can buy starter kits of bitsCenturion
has a number of starter setsShopbot
sells two different collections of Onsrud bits in starter sets:Router Bit Starter Kit (13699)Shopbot Desktop 7 Piece Bit Kit (13698) Some basic terminology:Straight:
Neither upspiral nor downspiral (see below)Downspiral or Downcut:
Down spiral bits push the chips downward back into the slot that was just cut. They are designed to leave a clean top surface of the material. They work well with vacuum hold down becauyse they place a downward force on the material and, at the right feed rate, they will pack the chips back into the groove that was cut so there is little loss of vacuum.Upspiral or upcut:
Up spiral router bits pull chips towards the shank and are great for plunge cuts. Good for doing fast cuts but can have some tear out problems on the top surface of the material. Not great for machines with vacuum holddown since they lift the material as they cut.Up/down or Compression:
The part of the bit near the shank is downspiral, and the part farthest from the shank is upcut. These bits are designed to cut sheet goods such as plywood and MDO in a single pass with minimal tearout. They tend to be more expensive and, because of the complicated geometry, they cannot be resharpened.Spiral O, Super O, or O flute:
Available in up or down cut, the Open flute allows for easier chip formation and evacuation, but also provides for a sharper cutting edge that delivers a better edge finish on a variety of materials. For certain materials these are the only bit that will produce a good result.Flutes:
The number of surfaces that cut the material as the bit rotates one revolution. For wood a single or 2 flute design seems to work best. Bits for working in metal may have 3 or 4 flutes.
If you don't buy one of the starter bit sets here is how you can put your own set together:
A 1/4" bit is pretty handy general purpose bit. Start with a straight bit and later try upspiral and down spiral bits. Buy a good brand such as Onsrud or Centurion
, but you should also try a super cheap bit. That way you can understand
the difference between a $2 bit and a $40 bit.
A 90° bit is great to try out V-carving. Try the ones from Centurion
. Later you can try a 60° bit for smaller lettering or a 120° bit if you are carving larger signs.
A 1/8" ballnose bit is great for doing 3D work. If the carving is less that 1/2" deep then you can get away with shorter, less expensive bits from MSC Direct. For carvings deeper than 1/2" buy the bits from BeckwithDecor.com
. They are beastly expensive and worth every penny
A large diameter bit (1.25" or larger)
for leveling your spoilboard is handly. You won't use it often, but when you do it will be glad it is there.