This afternoon Mitch and I went to the chamber and after putting a little extra pressure on the locking screws, we started taking tension off of the springs. All springs started around 2k lbs each, we left them with about 400lbs each. Before transferring load to the stops, I used the screws to push HEPI about 100 um above the reference position. RX,RY and RZ were all within 25urad, X&Y were about 80um away from the reference. Right now Z has settled about 100 um below the reference position, all of the other positions are nearly unchanged. First thing in the morning we will drop all of the springs to ~150lbs each and re-assess the position. If things are still good we will attach dial indicators and get ready to remove the actuators.

First attached image are the after (left side readouts) and before (right) IPS readings. Second image are the cartesian IPS locations in nm or nrad, left column is after spring relief, right is before.