(Corey, Greg, Jim)
Unit#3's Pesky Rotation
Over the last week Jim & Greg have been addressing floating issues with Unit#3. Stage1-2 floats well, but Stage 0-1 is exhibiting an even larger rotation than what was observed on Unit#2. The first float showed a clockwise rotation, with dial indicators seeing a rotation atleast 0.060" (As Stage1 was floated, it would twist to the limit of the Lockers. To observe the amount of rotation, the Locker Base bolts were loosened and Stage1 continued rotating to the 0.060" value, until the bolts ran into their thru-holes.
Stage1 Parts were then addressed. The system was locked back up, Alignment Pins installed, and the Stage0-1 Flexures, Springs, and Spring Posts were removed. Jim & Greg used the Romer arm to take various measurements of the parts (both on a table and re-installed on Assy). What I understood from Jim, is that there was nothing glaringly bad from these measurements.
So, Spring Assemblies were re-installed on Unit#3. This time we went with different Springs & Flesure Assemblies. Before torquing the Springs down, we pulled on the Spring tips such that they were slightly "to the right" (where right is right if you were looking at the Springs from above--we were hoping to favor a counterclockwise rotation), and then torqued them down.
Thursday afternoon Stage0-1 was refloated: Alignment Pins removed, Lockers unlocked, and unfortunately, the system exhibited clockwise rotation. The Lockers were adjusted horizontally to accomodate this rotation. This time the Locker Base bolts didn't butt up against their holes and the worst observed twist was only 0.040". So, all Lockers were adjusted horizontally to accomodate this twist, and the system is set to accomodate this clockwise Stage0-1 rotation. Obviously, the Stage0-1 Alignment Pins will no longer work with the current set up.
Here are the s/n's for the new Flexures:
As Of This Morning......
Jim found out with this rotation, we are not able to mate the Large Actuators between Stage 0 & 1! The horizontal gap is just too much for the L-Brackets.
Received Crates of GS-13's & L4C's
These crates were received on 9/22, and are inside the Staging Bldg.
Transitioning BSC Back To HAM
Since the next assemblies to be built will be HAMs, have started the task of bagging up/storing BSC parts/hardware to make room for HAM stuff.
Unit#2 Work
Install Spring Hatches, Secure Wall weights, & Install Bread Boards (procedure calls out for 1/4"-20x1.5" long bolts for the breadboards, and this is probably too long by 1". I went with 1/4"-20x5/8" bolts).