Focus: Shim the elevation rails
Shim the elevation rails:
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Compute the pitch,roll, and focus error of the dome as
it moves up the elevation rail using the theodolite data
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Shim the elevation rails to correct for this error. This
will correct for the tilting of the platform do to the weight imbalance.
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The pitch and focus errors vs za change as we move 60
degrees in azimuth. We shim to minimize the errors (we can't make it go
to 0).
Shim the azimuth rails:
Using a theodolite at the rotary joint measure the deflections
of the azimuth trolleys as they move around in azimuth.
The azimuth trolleys are spread over +/-18 degrees
of azimuth. Shim the azimuth rails to minimize the deflections in azimuth.
Iterate the measurements from AO9.
-
Redo the measurements from AO9. Go back and touch up any
elevation rails shims that are out of spec. Try and shim to about 1 mm
(1/32 inch).
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