I use a lot of metal cutting endmills as router bits on the CNC router - they work great and are often much cheaper than router bits of similar design. HSS will dull too quickly to have any cost advantage.
As mentioned, keep your feedrate high enough where you are getting chips, not dust. Sometimes you would be surprised how fast you should be cutting and how well it works! Don't be afraid to take roughing and finishing cuts if you are looking for a good finish.
Keep the tool bits clean - this is critical. If cutting manmade materials (plywood-MDF, etc.) the glues will bond to the cutter slowly. When cutting hardwoods (or any real woods) the pitch will build up on the cutter slowly. As some point there is enough "Gunk" on the tool where the buildup increases dramatically, and very quickly. Once this starts to happen the tool overheats and is generally ready for a re-sharpen - yes overheated carbide can be resharpened.
Don't wait for the build up to become a problem - clean the end mills frequently. If you look at the land (the flat looking area just behind the cutting edge of the flute) you will see the build up starting, once you see something there, clean the tool. I have found that if you soak the tools in a cleaner called "Simple Green" it will remove the resins pretty effectively.
This product isn't nearly as nasty as oven cleaner or some of the other application specific chemicals that are out there. I keep some in a coffee can (nearly full) for this purpose. However, I also clean other woodworking tools in the same can. If you have a drum sander you probably have learned that they too build up with pitch pretty quickly. If you soak the rolls of abrasive cloth in the coffee can over night, then rinse it off with water, the resin is gone as well and the belt looks like new again and are ready for more abuse (opps, meant use).
Primarily though two things help a lot...
1) Feed fast enough that you are cutting (the same is true in metal working, if you cut too slowly (feed rate) you will rub the tool dull).
2) Keep the tool clean - remove the pitch before it builds up
Chris  |