Pink plate is controlled by three step motors via blue timing belt drives, green sliders, violet and yellow bars.
Each slider is fixed to front branch of its belt.
Axes of three revolution joints of the plate are perpendicular to each other.
The plate is kept always horizontal and can move without rotation in three directions of a Cartesian coordinate system XYZ. Its displacement in X, Y or Z direction is equal to the one of the slider that moves in X, Y or Z direction respectively.
It can be used for 3D printers, pick and place devices.
See a real tripteron: