A 180 degree movement (12 o’ clock to 6 o’ clock in a clockwise direction) transposed into a180deg shaft rotation with no mechanical components present at the pivot point or in the swept arc after movement (i.e right hand side of clock face) Example: I’m currently designing a sophisticated folding leaf table as a home project. The key features I would like to incorporate into the design are: Firstly, a traditional leaf table uses a piano hinge positioned so that when the table is folded open 180deg the axis of the hinge is just above the surface of the table. I intend to use a 180 degree hidden hinge so that the table has a flush surface when folded open. Note that the point of rotation is slightly above the surface of the table so that when the table is closed the two surfaces are held about 4mm apart. Secondly, (and perhaps most difficult) I would like the rotation of the table leaf to be geared to the rotation of the supporting structure without any of the gearing system protruding above the surface of the table when opened Can anyone suggest a mechanical system that would for fill these requirements? The problem I can’t seam to get around is that below the flush surface of the table there is always less than 180 degrees of space around the pivot point. My history is in ship structures but I have never studied mechanical engineering, can anyone recommend a good site for introducing someone to geared systems and the different types available.