hah, yup i gathered as much, but since i dont really have access to a mill, the drill press method is more through neccessity than design.\
I do, however, have a brother who works at SKF bearings here, so I will look into getting side load bearings for my drill press and give it a shot - im not after 100% accuracy here (obviously, the vibration from a drill press is far more than that of a decent mill) but it will allow me to do flat bottomed channels with a mill bit.
My understanding of rotor's design is that of a tumbling turbulence - the water 'rolls' accross the bottom of the inverted cone shaped holes that the drill bit has left, up the sides, hitting the ridge, and rolls back down the other side etc. The pins help in removing the head by adding extra surface area? The rolling allows more water molecules to touch the surface of the copper and adsorb the energy.
Well, thats my theory at any rate
The pump I am using is very similar to an ehiem 1048 in pHaetus's graph of pump flow vs. head (I think, cant remember the exact title of the graph).