re WP 3999

We swapped the Parker Valve on BSC2 NE Vertical Actuator.  It went smoothly with little mess.  This Vertical Actuator remains in bleed mode for a time, at least an hour or several.  This means vertical drive of this corner is not possible.  If the HIFOY crew can not proceed come early afternoon, we'll forgo any further bleeding and put it back to Run mode for driving.  Otherwise we'll put it back into Run mode first thing tomorrow.  At the moment this disturbed position is not critical for the HIFO crew.  Attached are trends of the global position, it sure would be nice if the frames had the units contained...  I believe the units presented are nanometers & nanoradians.  So the horizontal positions are back: X, Y, & RZ; but, the vertical dofs are not.  Again though, currently, the HIFOY crew can work with it the way it sits.  If you think about the location of the corner we have disturbed, it's likely we have tilted the table around the barrel of the optic and therefore possibly have only rolled it.  Looking directly at the vertical IPS readouts of corners 2 & 4, (not plotted) there is a total pitch about the NW-SE axis of 1.5mm over the ~4m distance between the diagonal piers giving a roll of ~0.4mrads.