here is what I think we could do with a top pantograph
onshape parts for top pantograph
note the steep cutouts needed for chain clearance when in the bottom, near corner
onshape assembly for top pantograph
in the onshape assembly, you can grab parts and move them
I may need to fiddle with the lengths.
for those who have been doing the graphs, are there any dependencies between the horizontal and vertical bars? or am I right in thinking that the horizontal ones have to match each other and the vertical ones need to match the sled?