Friday, March 5th, 2009: Doug's Work Log

  • Mounted Hexapod and Dummy Hub on crane
  • Mounted DM672a on Hexapod
  • Mounted Retro-Reflector Holder on Dummy Hub
  • Connected Hexapod cables
  • Marco tested six positions of closest approach of DM672a. Five were vertical collision points of the miniskirt/thin shell with the inside of the G-ring and one was a horizontal motion (up) and the collision of a coolant pipe with the dummy hub/G-ring interface. The results for the vertical clearance was good, with the measured clearance equal to, or greater than Marco's theoretical distances from his simulations. The horizontal test had good clearance, but it was difficult to get a good measurement of the clearance. A good measurement is useful to confirm Marco's models are correct (although the vertical tests confirmed that they are good). See Monday, March 9 for more on horizontal clearance measurements.
  • Found the coordinate system of the OSS is rotated 180 degrees around the z-axis relative to Lorenzo's software. After looking into Paul's code, I found he has a factor of (-1) on the X,Y,Rx,Ry terms that are sent to the UMAC (ie rotation of 180 degrees). The OSS coordinate system is consistent with the coordinate system at the telescope. When the telescope is at horizon:
    • +x axis is to left when looking from primary to secondary
    • +y axis is up
    • +z axis points from primary to secondary
  • Need to confirm that this coordinate system is correct. Also, need to decide if UMAC firmware should be changed to be consistent with the telescope coordinate system or if the software (OSS and Lorenzo's) should make the transformation from UMAC coordinates to telescope coordinates. Either way, the coordinate system used in the Solar Tower should be the same as at the Telescope. !!Send Emails!!
  • Put the hexpod/hub/DM672a in a safe position for the weekend.
    • Removed hexapod cables
    • Removed retro-reflector holder
    • Transfered the "Unit" to a beam mounted on the lower flange of the Solar Tower pipe with short straps so the Unit would not swing (much).
    • Parked crane at the top of the Solar Tower and put cover back on.
    • Covered the Unit with plastic

-- DougMiller - 09 Mar 2009
Topic revision: r1 - 09 Mar 2009, DougMiller
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