Originally Posted by zephyr9900  Larry, for 90% of my work I use Atrax carbide endmills from Enco. Carbide is much stiffer than HSS which means less cutter deflection and a better surface finish in general. Atrax are American-made cutters and much better quality than the cheaper Asian bits and not that much more expensive.
With the carbide bits you need to use the ER collet-style holders because carbide bits don't have setscrew flats, and will walk right out of a setscrew-type endmill holder. I only use the setscrew holders for occasional-use HSS bits I already had.
I use flat endmills in 3/8, 1/4, 1/8 and 1/16 diameter and ball-ends in 1/4 and 1/8 for most of my work, the latter for 3D contouring. I have used bits down to .020" in the Proxxon spindle so far.
For that matter, I don't use the 3/8" bit all that much. With manual machining I would always use the largest bit I could to minimize the handle cranking to clear out material, but with CNC it is trivial to set the stepover distance to match the bit and let the machine do the work. The 1/4" bits, flat and ball, get probably 75% of my use.
Best regards,
Randy |
Randy, I thought the same thing, and then asked Greg at Tormach. He said it would pull the tool out of the R8 collet before it would move from the setscrew with a carbide bit and no flat.
I have been using carbide with the set screw holds since... and have had very good luck! I have had the tool holder pulled out on a 1/2 inch bit and the set screw didnt budge with a carbide bit.
David