2-Axis Animatronic Eye w/ Eyelids

This is the animatronic eye mechanism I designed for my Balloon Boy project.
The eye can move in both X and Y directions, and both eyelids move independently for more realistic motion.

The linkage system works with either:

• bent paperclips
• or M2 rods + ball joints for smoother movement (recommended)

Assembly is pretty straightforward, so I didn’t make a full tutorial this time.
You can see how everything goes together in the photos.

Before attaching the servo horns:

• set all servos to 90°
• make sure the eye and eyelids are centered/in their neutral position

Hardware Needed (per eye)

Servos

• 3x MG90S / SG90 micro servos
  (any servo around that size should work)

If using paperclip linkages

You’ll need:

• 2x ~18mm M3 screws (eyelids)
• 1x ~10mm M3 screw (eye movement)

If using rods + ball joints

You’ll additionally need:

• 4x ~10mm M2 screws
  (for mounting the ball joints to the servo horns)

Magnetic Eye Attachment

The eyeball and base both include optional magnet holes so the eye can attach magnetically.

Magnet size:

• 10mm diameter
• 5mm thickness

You can also just glue the eye in place if you want.

This upload only includes one eye, but you can print a mirrored second one for a full pair.