In preparation for the vent, I centered POP QPDs so that we can use it as an alignment reference when we will install HAM3 beam splitter.

Right now both POPA and POPB PIT and YAW are all within +-0.015.

QPDA sum is 56.3, QPDB 51.7 using straight shot.

POPA picomotor counts are: X -331, Y -28257.

POPB picomotor counts are: X 4151, Y 20661.

Not unlike TMS picomotors, these are sort of degenerate. You can use pico B to center QPDA, then pico A to center QPDB, and repeat thousands of times to eventually have a good centering. You can also overshoot repeatedly to make it quicker. For example, when QPDB is too low while QPDA is centered, you use pico A to bring QPDB up, then pico B to bring QPDA down, and repeat.

The sled is sensitive to even 1 step of the picos. Medium step (100 steps) is safe to use without worrying too much about losing the beam, but if you want to use Large (1000 steps), be prepared to lose the beam on both of the QPDs.