Brushless motor question

[tnrcboatracer]

I have a question regarding the brushless motors: are these motors rated for continuous duty? I'm thinking of using a brushless motor and controller for a high speed spindle drive on a CNC mill application. The HP is plenty for for my application, but I don't know how well the controller would hold up in continuous operation. I can hook up a radiator cooling system to keep the temps on check. Any thoughts would be appreciatede.