JimW EricA Greg

This morning we disconnected the HEPI Actuators because the YAW correction needed by IAS was ~200urads or about .4mm at the HEPI foot.  The range of motion is only +-1mm, plus, the attached actuators will fight that amount of motion and cause non-expected responses.  Jason tweaked up the IAS gear and gave us the confirm on moving.  We brought it from 180urad CCW to 15urad CCW with 1/4 of a turn on each of the big Double Start Counter Wound (DSCW) HEPI Springs.  After lunch we set to reattaching the Actuators and while we'd like to see better centering of the Actuator Plates for max range of motion I think it will be plenty.  We'll have to really do driven range of motion measurements to determine this.
In the end based on the Dial Indicators relative the last In-Chamber Vertical survey of the optical table and post this mornings move and OK by IAS, HEPI has Yawed the Optic from 15urad ccw to 35urad cw (still in spec).  We also improved the level of the optical table, depending on how the tilting of the HEPI actually translates into the tilting of the optical table, from 0.5mm p-p to 0.3mm p-p.  So again all good; really we just got lucky.

I've attached a few pages from my logbook recording the in-chamber vertical survey and all the HEPI DSCW Spring adjustments and the Dial indicators readings.  Let me know if you want a guide or tour.