Our house has a 2-zone heating and air conditioning system. Today is the third time in the same number of years that one of the automated damper has broken. The problem seems to be the CAM (P/N DURO DYNE C 005096) that triggers the limit switches inside the motor is made of a flimsy plastic and easily break. Instead of trying to replace with two adjustable CAMS my design includes one, thicker CAM which I modeled in OPENSCAD. Details can be found on my blog: https://colbrydi.github.io/air-conditioner-cam-replacement.html Please let me know if you find this useful.