The transfer functions measured on HAM3-ISI, after the installation of MC2 and PR2, featured non-matching eigen frequencies between corners.
I tried adjusting the cables coming from stage 1 and going to stage 0 so they don't rubb against stage 1, Stage 0, or each other. I also made sure the loops for the cables were large enough so they don't affect the overall stiffness observed on the ISI.
I finally found the issue of the eigen frequency mismatch we observed by checking the cables of the horizontal actuators, which are set along the spring posts: they were rubbing against stage 1. I adjusted them and the eigen frequencies measured on the ISI now match.
It is hard to see around the horizontal actuators with the actuator-doors on, and I did not run a transfer function after each adjustment so I am not sure of which cable(s) was(were) causing trouble.
Pictures and figures are attached.