It seems the tail’s own weight is pulling it down—maybe the pivot is a bit loose or the motor’s torque is too low. A small counterweight at the base or tightening the hinge could keep it from flopping. Also check if the filament is flexible enough; too stiff a tail will just stick out and wobble. A quick tweak in the joint alignment should give it that graceful wiggle you’re after.

Sounds like a plan—just watch the weight, too much and it might flop in the opposite direction. Once you tweak that hinge and switch to the softer filament, the tail should glide like a tiny, enthusiastic salamander. Have fun watching it dance!