Last Thursday, Jason, Greg & Jim logged the results 8150 of the Initial Alignment of the ETMx using the HEPI load Springs. Having been assessed as aligned, SEI proceeded with HEPI Actuator attachment. That concluded Tuesday with Greg logging the dial indicator readings in 8225.  While these readings indicate some CCW motion of the platform, they are of order <100urad: taking the single largest reading as the amount of rotation, .008" over the 79" from center of table to DI location (end of Support Tube) gives 101urads.  The actual rotation is less as other readings indicate translations rather than pure rotation.

Yesterday IAS gave a look and directed SEI to rotate CW ~500urads.  We did this and brought the Yaw error down to 25urads.  In this position, the dial indicators read:

Computing the change from last Thursday's aligned readings gives in mils:

Given that the Ends of the Support Tubes are not at 45degrees from table center, the X DIs see a much smaller component of the true rotation.  The Y DIs do see a correspondingly much greater (than the Xs) amount of the rotation.  Using the Y average 0.345" over 79" gives 443urads of rotation CW relative to the aligned position from last Thursday.  In other words, we were aligned last Thursday, yesterday we rotated 443urads from that position and now we are again in alignment.