[Garegin]

Hi all

I am from Armenia. I have cnc stone working machine. I am trying to engrave a big granite rock. but have some problem with it. The stone dimensions are 180x80x15cm. The engraving depth is 10-20mm (it varies from the model it is engraving). The engraving tool is 20mm tool hard-grained diamond (know it is quite big for granite but the spindle is 6 kw and it can handle it easily) z feed is 0,3mm, processing speed is 3000mm/minute . I have tried 12mm diamond tool but the work time increased dramatically. The problem with engraving is that tool stop cutting stone and start burning with big noise. It can be because of steel parts in the stone but usually it should last for a moment and continue it's work. After working for minute or so the machine stops and bring error of overloading (the water is plenty so it is not water problem). If somebody is familiar with granite engraving please advice optimal processing settings and please advice if I am using correct type of tool. Which type of diamond is more efficient for hard stone hard grained diamond or fine grade diamond?

Thanks

Garegin

[marktill]

Hi ,

you should have fine ( small grains ) say 44 grit diamonds in a med / soft bond. If you are getting burning drop the rpm down . also you may do well to back of the side ways feed to less than 2000mm but make the Z feed 0.65mm . By slowing down the rpm you will get some big changes in the way it all works. Also check that the water is able to get inside of the center of the tool, some time the water gets pushed away from the the tool from the the out side it looks like you have good coolant but in real term the center is running dry .

MT