Hi Wayne,
Many thanks, you provide lucid insight with few words.
I am struggling through the examples and still can't get my head around a "Coincident Relation". I need to attach the mid-point of a folded piece of sheet metal to the mid-point of a sketch above it for allow me to add a tab. It appears that the mechanism to connect these mid points is the use of a Coincident Relation. This will ensure that the Tab is centred on the folded piece.
The folded piece is Black, so I think that means that it is resolved, and therefore fixed. The sketch is blue, so I assume that it will move towards, and attach to the folded piece when I have completed the operation correctly.
Are my observations and assumptions correct ? I have spent quite a while right clicking mid points of lines, only to see them vanish when I right click the surface that I want to attach to. I have seen A Coincident pop up in "add relation" once, but trying to accept it told me that illegal geometry would result.
Any indicators to what I am doing wrong will be appreciated.
Thanks,
Mark.