Hi Jonathan, and jazzcnc.
Jonathan many thanks for the info I hope this will get me in the ball park, Jazzcnc that's a big difference in chip load, where can I find more information on line about chip loads and calculations, I know about GWizard But I would rather have one with no cost or a one off payment as I mainly will cut ply and balsa and some small parts in aluminium. Once I can get near the correct settings I would have no or very little use of Gwizard calculator and yes I have been plunging into the aluminium but a very slow rate.