Thanks Irving2008 goes some of the way but still not clear how reproducible partial steps are when under load as the bit I read on the web inferred that steps between full and half were hit and miss not that I fully understand but I would think that as one of the coils only has partial power then its actual position will be influenced by the load.
So I would think that greater accuracy could be achieved with gearing albeit with a slower responding unit being as I want to make fairly small parts I think I should have gone with gearing instead of direct drive, only time will tell.

Peter