Hi, I have a good quality solid CNC router mill. When I try to cut thick ply or cabinet board etc using a 2 flute endmill, the cutter gets terribly hot. For example at the moment, cutting pieces from 18mm thick ply sheeting - it cuts very easily but the cutter is smoking after a cut that takes a minute or so. I have tried various sized cutters and different stepdowns per cut. At the moment I'm using a 4mm endmill and 9mm depth per cut, feedrate around 3000mm/min and 16000rpm. It's throwing chips nicely, not creating much dust, and the cut is quite sharp and smooth.
Being a narrow deep slot it's hard for the heat to get out so I've tried vacuuming the dust out of the slot by hand during the cut (the main vacuum head isn't powerful enough to pull the dust up out of the slot). And now I'm using a jet of air from the compressor directed to the tip, to both blow out the chips and cool the cutter. But it's still hot enough to burn chips at the end of the cut.
The way I've normally dealt with this is to use smaller stepdowns and do a double width cut each stepdown, to create a wide slot. But this takes a lot more time. I can't understand how the cabinetmaker workshops do it - they seem to be able to cut through 16mm dense laminated board in one fast cut. What sort of cutters do they use?
Any tips greatly appreciated! Thanks,
Andrew vB