I'm about to buy a 3-axis router whose main function will be 3D milling of small brass parts with a lot of surfacing. The cutting area is 24" x 31" x
5", and the machine is extremely solidly built compared to many I have look ed at. I'm opting for this unit because I also want to use it for a variety of woodworking operations. The seller is a moldmaker with a collection of CNC machines, both knee mill and router based. He says that I shouldn't buy the machine because it is simply not fit for working in brass. His argumen t is not based on the stability of the machine, but the spindle, which is 1 .5kw, and runs at 8000 to 24000 rpm. He cuts aluminum and plastic with this spindle, but uses heavier machines with slow spindle speeds for brass.Now I must admit that my CNC experience is only with knee mills and slow sp indle speeds, but my research leads me to believe that high speed routers c an cut brass just fine, as long as you do it properly. He also said that fo r brass I shouldn't implement a spray lubricant, but instead a good vacuum system. He uses spray for aluminum, but says it's not necessary or appropri ate for brass. This makes sense to me. The guy is obviously very conscienti ous and doesn't want to sell me something that isn't going to work, but I t hink he might be less that up to date on how HSM is now being implemented f or nonferrous. I've talked to some other manufacturers of similar machines who claim I can even use their systems to cut stainless, as long as I have proper cooling spray.
So, any tips or links on high speed machining of metal?