I was hoping someone may be able to answer why I cannot seem to mill MDF from a ProDesktop file without it sounding like the machine is going to break?!?!?

I am trying to cut a 3D model of a CD tray which will then be vacuum-formed but each time I set it to cut the machine starts 'banging' and sounding like it's not operating in the usual way. I have also tried both 6mm ball end tool and the other type which cuts a flat edge (sorry can't remember what it's called!)
Fingers crossed you can offer some advice!
Thanks,
Zoe
