Hi Pilou and Michael,

Thank you for your replies, both of which solved my question.

The reason I asked was that I needed to place a cylinder in an exact position on a clock back plate to 'drill' a hole.

re OWC: I understand the problem now Michael. I was of course only thinking of my particular problem. And also thanks for the explanation, very clear and succinct.

I also have to say I am most impressed with MoI3D, in particular, I needed to use imperial measurements and it was a delight to be able too enter 3/16" (for example) as a distance, rather than converting it to pixels, mm or units first.

regards,
Mark.