----------------------------------------------------------------------------- Mauna Loa Solar Observatory Observer's Log ----------------------------------------------------------------------------- Sun Aug 22 16:38:05 GMT 2004 Year: 04 Doy: 235 Observer: koon WEATHER COMMENT: Sun Aug 22 16:38:07 GMT 2004 Fog and light rain, wind=15 mph from the SE, temp=43F. COMMENT: Sun Aug 22 16:40:43 GMT 2004 No obs until fog and rain clear away. WEATHER COMMENT: Sun Aug 22 22:52:13 GMT 2004 Fog and rain have receded downhill, starting most instruments. ECHO COMMENT: Sun Aug 22 22:52:43 GMT 2004 Time OK. MKIV COMMENT: Sun Aug 22 22:52:53 GMT 2004 Centered occulting. Sun Aug 22 22:53:08 GMT 2004 MKIV Start Patrol Sun Aug 22 22:53:26 GMT 2004 CHIP Start Patrol Sun Aug 22 22:53:39 GMT 2004 PICS Start Patrol PSPT COMMENT: Sun Aug 22 22:58:47 GMT 2004 Not observing, troubleshooting dome azimuth slippage problem. Sun Aug 22 22:59:27 GMT 2004 MKIV End Patrol Sun Aug 22 23:19:16 GMT 2004 MKIV End Cal Sun Aug 22 23:58:30 GMT 2004 MKIV Start Patrol NICE CHIP IMAGE: 2338 NICE PICSLIMB IMAGE: 2337 NICE PICSDISC IMAGE: 2311 NICE MK4 IMAGE: 2303 Mon Aug 23 02:10:40 GMT 2004 CHIP End Patrol Mon Aug 23 02:12:27 GMT 2004 PICS End Patrol Mon Aug 23 02:14:53 GMT 2004 MKIV End Patrol MKIV COMMENT: Mon Aug 23 03:21:04 GMT 2004 **PSPT PROBLEM**: Mon Aug 23 03:21:09 GMT 2004 I did a lot of studying of the PSPT dome azimuth slippage problem that has plagued us when the dome starts from certain positions, mainly a large NMorthern sector and a smaller South pointing sector - if the dome is pointing in these areas then the az motor may slip trying to overcome the friction of the static dome. Besides normal static friction there is a place where the inside of the dome skirt rubs against the outside of the not-quite-circular dome support wall. The rubbing occurs at the covered seam in the static ring of roller mounts that is installed on the top plates of the support wall. There are 5 covered seams but the Eastmost static seam is the rubber. There are 3 sections of rails that are attached to the dome inner skirt, one of them is bent out of shape but probably still usable. The increase in friction when starting from certain positions of az causes the az motor gears to slip in the springy racks and so the encoder which is fixed with the motor reads erroneous positions sometimes until the dome gets Homed again. So we need to reduce or prevent that dome rubbing friction, and I think the software should be changed to prevent pointing the dome slot in a Northern sector from the Home Position to an equal place to the West of North, a no-point sector. Maybe we could also move the Home switch more East and less North of its current position. I suggest not using the PSPT until we can find a solution so we don't further damage that bent dome rail. Note that the rubbing always occurs at the same place no matter where I point the dome, so the dome isn't as noncircular as the dome wall mounts are. -Darryl Mon Aug 23 03:42:18 GMT 2004 MkIV 00_01.rawmk4 00_37.rawmk4 01_09.rawmk4 01_42.rawmk4 22_53.rawmk4 00_04.rawmk4 00_40.rawmk4 01_12.rawmk4 01_45.rawmk4 22_56.rawmk4 00_07.rawmk4 00_43.rawmk4 01_15.rawmk4 01_48.rawmk4 23_03.rawmk4 00_10.rawmk4 00_46.rawmk4 01_18.rawmk4 01_50.rawmk4 23_09.rawmk4 00_13.rawmk4 00_49.rawmk4 01_21.rawmk4 01_53.rawmk4 23_15.rawmk4 00_16.rawmk4 00_52.rawmk4 01_24.rawmk4 01_56.rawmk4 23_58.rawmk4 00_19.rawmk4 00_55.rawmk4 01_27.rawmk4 01_59.rawmk4 c22_59.rawmk4 00_24.rawmk4 00_58.rawmk4 01_30.rawmk4 02_02.rawmk4 c23_06.rawmk4 00_28.rawmk4 01_01.rawmk4 01_33.rawmk4 02_05.rawmk4 c23_12.rawmk4 00_31.rawmk4 01_03.rawmk4 01_36.rawmk4 02_08.rawmk4 00_34.rawmk4 01_06.rawmk4 01_39.rawmk4 02_11.rawmk4