Pictures of azencoder a 270 marker

27jan12

    The azimuth has an encoder on each side of the encoder rack gear. encoder 1 is on the dome side and is used for pointing the telescope. encoder 2 is on the ch side and is used to measure the bending of the azimuth arm.
    A reference scribe mark has been placed at 270 degrees on the ring girder. The telescope can be moved to az=270 and then a pointer (on the azimuth arm) can be slid out to meet this reference mark. When changing encoder 1, we can use this reference mark to make sure we come back to the same encoder value.

    Pictures were taken of the pointer and pointer to use as references. The correct position for the pointer on the reference mark is whereever it was when the last pointing model was made.

Some Notes:

26jan12 - Encoder 1 replaced

    If the pictures are correct, the az encoder moved by 1.5 mm or 15 asecs on the encoder. this is about 4.5 asecs at za=15.



to vertex hardware page
 

home_~phil