Thanks to DC's fix, we can now print at high resolution without the workaround - I printed a new set of Z gears and have attached a photo below showing the orginal RRP one (as a common reference) and one sliced at 0.04mm (sorry Ian, it would have taken a day longer to print at 4 micron:p). I used 40 percent infill every 3 layers (so infill was 0.12mm). Looks like I'm still under-retracting, but the extrusion seems very good, and there's no (or little) z banding. The height of the original gear is 13.15 mm, and so is the 0.04mm sliced version - which I take to mean that there isn't much error in Z (there were 328 layers in this).
to my eye, the blue gear looks pretty smooth and matt (though I can see the layers on the orange gear at the same distance) - the microscope/web cam I'm using shows more detail, and makes the blue look out of focus (but it isn't). I didn't remove any whiskers, and the blue gear is as-printed (no sanding/filing) I think a light snading and some acetone and it'll look like it's injection moulded.
[edit] also, the horizontal edges, eg on the top surface, feel SHARP and smooth, the vertical edges show some drift, probably because of y belt tension and slippage of the table top relative to the table, and some noticeable lack of constraint in rotation about Z (I'm not sure if my Y bearing mounts are loose or the vertical rib under the bed that they mount to has play, will check this soon) [ /edit]
Edited 1 time(s). Last edit at 01/12/2014 02:05PM by rayhicks.