vatt:vatt_stall
Recovering from a Stall
| Jun 14, 2021, P Gabor et al. | ✔✘ | ||
|---|---|---|---|
| Control room |  Mirror cover must be open. | ||
| Control room |  If you want to close the dome slit (may be a good idea esp. when windy), close the mirror cover (assuming that the breaks came on when the stall occurred), than close the dome slit, and then open the mirror cover again. | ||
| Control room | Turn on the dome floodlights | ||
| Control room | Breaks off Be ready to set the breaks again if the telescope slumps in elevation when the breaks are released (watch the telescope in cameras,  and watch the elevation value in TCSglue) | ||
| Control room | Keep dome tracking on | ||
| Dome, lower lvl | Inspect the “flippers” and find the double-headed bumper. You will need to spin the telescope back to its stow azimuth. Remember that: | ||
 the double-headed bumper “lives” in the South |
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| from your vantage point at the dome's lower level, a flipper may show a green patch or no patch; you can never see a red patch from there |
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| Safe (recommended) | Less safe | ||
| if both are green, simply align the arrows meticulously | if both are green, simply align the arrows within a few inches | ||
| if one is green and the other has no patch, spin towards the latter, flipping it to green; then keep spinning until the arrows align perfectly | if one is green and the other has no patch, spin towards the latter, flipping it to green; then keep spinning until the arrows align within a few inches | ||
| Basement | Disable the hydtrostatic bearing: Turn Stage 2 off. | Does not apply | |
| Dome, upper lvl | Move the telescope to zenith | Step onto the telescope yoke platform carefully (avoid imparting angular momentum in azimuth), and move the telescope to zenith | |
| Dome, upper lvl | Turn the derotator (considerable force is required) back to home, untwisting the cable bundle | Still standing on the yoke platform, turn the derotator (considerable force is required) back to home, untwisting the cable bundle | |
| Dome, lower lvl | Align the Azimuth arrows accurately | ||
| Dome, upper lvl | Bring the dome to its home position (gently spinning the encoder wheel) | ||
| Basement | Enable the hydrostatic bearing: Turn Stage 2 on. | Does not apply | |
| Control room | Set the breaks | ||
| Control room | Close the mirror cover | ||
| Control room | Close the dome slit (if open) | ||
| Control room | Turn Thermal control off | ||
| Control room | Stop Autocollimation | ||
| TCS room | Reboot VATTtel | ||
| Control room | Close and open TCSglue | ||
| Control room | Start Autocollimation | ||
| Control room | Turn Thermal control on | ||
| Done! | |||
vatt/vatt_stall.txt · Last modified: 2021/06/17 22:46 by paul
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