ABCD: parallelogram
OCE: straight line
O: immobile
OE/OC = BE/BD = k = constant
Figures traced by pointer E and pin C are similar.
Scale factor is k.
This is the case when the red tools are immobile (not installed in place of pin C) and the orange pantograph is connected to system of slider and parallelogram (by pin C and a hole of the green plate). The system enables the green plate to move translationally.
Red tools trace red figures on the green plate. They have same size with the figure traced by pin C but upside down.
Two workpieces are machined at the same time.