Thanks for getting back to me Mark, much apprecited.

The Magneto Bearing looks ideal and avoids the need to install belleville washers by the looks of it? If going down this route would I use one magneto bearing between the chuck and housing and one standard bearing between the housing and motor?

I am hoping to cut wood but perhaps starting with an old computer ATX power supply will let me feel my way into the power question - sounds like this might be waht you are using.