Travis, Gerardo, Jordan, Betsy, Tyler, Richard

This afternoon we began the process for opening GV20, following the procedure outlined in E2600314.

To prep, Tyler machined a 7/8" hole in the 8" diameter handwheel so we could drive the gearbox by hand. We then closed GV19, measuring the distance from the top of the clutch body to the top of the ball screw in the open and closed positions. 

Open: +37 9/16"  Closed: -10 5/16" (zero is the top of the clutch body)

Moving on to GV20, the motor had been decoupled from the gearbox yesterday, so we again confirmed the measurement from the top of the ball screw to the clutch body with the valve closed. 

Closed: -10.125" (zero is the top of the clutch body).

Then we torqued the loose set screws on the top clutch retaining nut. We confirmed there was only 1 set screw per hole, but they were not brass tipped set screws as expected.

We then proceeded to check the set screws on the drive shaft collar/ball nut. We had to rotate the drive shaft in order to access to these set screws, so we began turning the handwheel clockwise, per procedure at 1:48:40 Pacific. There was some increased resistance after~20 turns, and then at turn 31 the clutch popped (1:56pm Pacific). We stopped and called Jon F to discuss. We re-measured the ball screw position and found it at -10 5/16", so the ball screw had been driven down and that's what popped the clutch. We then turned the hand wheel counter clockwise with a scale on the ball screw and confirmed it was indeed raising. After 15 turns, the clutch reset and then at turn 31 (net 0) we stopped and re-measured the ball screw and it had returned to -10 1/8". We then checked the ballnut and confirmed no threads had been exposed. 

We then met with the rest of the group on Zoom to discuss before proceeding with the rest of the procedure. We decided to continue raising the valve until we could check the set screws on the drive shaft collar, then raise it 1" past the point where the valve un-cams then set it back down 1" to confirm operation and rotation is as expected.

So we continued raising the valve by turning the handwheel counterclockwise, stopping every 50 turns to inspect the ballnut and measure the height of the ballscrew to confirm it was raising. At turn 171 (3:22 pm) the valve state turned from red to yellow on the medm screen. We used this as the point of "soft close". The ball screw height was exactly -9" at this point. We noticed a small amount of oil dripping from the gearbox during raising. We then continued raising for the 1" test after turn 171 (expected 150 turns per inch, so 321 turns total) again stopping every 50 turns to check the ballnut. When stopping rotation of the handwheel, it rotate slowly backwards (clockwise), but would stop after varying fractions of a turn (maximum was ~1/2 turn, with caveat that I never fully released to wheel, so I could stop rotation if needed).

Once we got to turn 321 (3:37:40 Pacific), we stopped, checked the ballnut and measured the ball screw height of exactly -8". We then lowered the valve by turning the handwheel clockwise back 150 turns (3:49:00 Pacific), where it will remain overnight. By this time more oil had dripped from the gearbox, we put a foil tray underneath to collect any oil that may come out overnight. Pictures below are of the oil at the end of the day, after lowering the valve back to soft close position.

We will meet with the group tomorrow morning to decide the next steps.