According to Rana, the following is the "new" (should always have been used, but now we're going to enforce it) earthquake stop backing-off procedure:
1. Back all EQ stops away from the optic, so that it is fully free-swinging.
2. Confirm on dataviewer that the optic is truely free-swinging.
3. One at a time, slowly move the EQ stop in until it barely touches the optic. Watch dataviewer during this procedure - as soon as the time series of the OSEMs gets a 'kink', you've just barely touched the optic.
4. Back the EQ stop off by the calculated number of turns. No inspections, no creativity, just math. Each EQ stop should be between 1.5m and 2.0mm away from the optic.
5. Repeat steps 3 and 4 for each EQ stop.
Note: The amount that you need to turn the screws depends on what the threads are.
FACE and TOP stops are all 1/4-20, so 1.5 turns is 1.90mm
BOTTOM stops are either #4-40 or #6-32 (depending on the suspension tower). If #4-40, 3 turns is 1.90mm. If #6-32, 2.5 turns is 1.98mm |