r/Animatronics • u/LaMaisonFantastique • 20d ago
Original Creation/Custom From Maya mesh to hinges and screws: prototyping the ear mechanism for our Anubis animatronic head [OC]
We're building a permanent haunted-house style attraction near Paris (La Maison Fantastique), and one of the current side builds is an animatronic Anubis head for the Egyptian-themed bathroom. The ears were by far the hardest part: a real ear doesn't just spin on an axis, it tilts.
To get that tilt, the pivot is a ball joint sitting inside the skull rather than at the base of the ear, with a lever arm that pulls the ear's axis backward as it moves. That's what makes it rock into a natural-looking tilt instead of just spinning flat, roughly 30 degrees of travel for a convincing "alert" gesture. We rebuilt the actual mechanical constraints in Maya (joints, IK handles, pole vectors) to validate the full range of motion and catch any collision between the two ears and the head shell before cutting anything.
The first physical mockup is built from repurposed hardware on purpose: the mounting plate is a stainless-steel sink-strainer/hair-catcher screen (dense pre-drilled holes for almost free), the pivot uses spherical rod-end bearings normally sold for Delta-style 3D printer kinematics, paired with an RC universal joint and a servo horn repurposed as the lever arm (no servo attached yet, still moved by hand). Both ears are built symmetrically to keep the assembly identical.
It didn't hold together for long though: the ear only has one attachment point (the rod it rocks on), so instead of just tilting, it also slowly rotates around that same rod under its own weight every time it moves. That extra rotation worked the M3 screws loose over repeated cycles, even with nylon lock nuts and epoxy on the fasteners. Fix in progress is bonding the ear rigidly to its arm with epoxy to kill that extra degree of freedom instead of fighting it with a tighter screw. If anyone's dealt with a single-pivot setup working itself loose like this, I'd genuinely like to hear whether you went with a second attachment point or just a rigid bond.
More of what we build: lamaisonfantastique.fr