CNC grinding & wheel dressing

A friend has been doing a lot of work with grinders, headed toward
making form cutters for clock gears. He asked me if I thought it
possible to build a CNC wheel dresser.

It seems to me it should not be to hard- the XY travel needs to be only
an inch or so, but the diamond should be arranged to point always
perpendicular to the line of travel.

Are there such things?

Anyone ever try to build one? Could Vector figure the angular axis to
keep the dresser pointed in the correct direction?

ron ginger