Both springs have been finally assembled on the Achilles tendon area.

They have been printed with different materials (both have a safety factor considered in calculation to account the material difference) and the new one (left foot) is definitely stronger. Additionally the salt annealing treatment enhances its fatigue life to the limit.

Functionality of both spring have been tested and they correctly guarantee the return of the leg in vertical position after the squat movement. Here is a preview video of both spring, both on the legs alone and on body.