Blog from December, 2022

Attendance: Gabriel

Date/Time: 12/13/2022, 20:30 -12/14/2022, 00:25

Spaces Occupied: Control Room, Dome

Goals: 

Slave the Dome to the telescope

LOG:

Skip to first note for solution...

1. During some slews of the telescope with the dome "slaved" to the telescope, I noticed that in the DFM TCS software the dome thinks it has the same azimuth as the scope, even though it is over 70° away.

2. Upon manually getting the dome aligned with the scope the first time, I notice that DFMTCS thinks the telescope's azimuth is 164.7 while the now actually aligned dome's azimuth is 250.0. Below I have made a table with all my attempts.

   Try#	Scope Azimuth	Dome Azimuth (Manual Tracking)	Difference
   1	164.7	250.0	85.3
   2	4.5	69.6	65.1
   3	58.7	132.6	73.9
   4	127.5	205.0	77.5
   5	299.2	6.3	67.1

3. I can't say with certainty that there is a pattern in the differences of the (perceived) azimuths, and I won't get any more data to confirm or deny this for now (too time consuming to do alone) ,but there might be a linear (ish?) correlation between the percentage differences of the azimuths based on either the position of the dome on the circle , or just based on the overall rotation of the dome. If the latter is true, then it is very likely that the belt on the rotation measuring motor (lack of a better word, please edit to fix) is missing some teeth, or the motor itself has faulty sensors. Inspection needed.
4. Upon further inspection, the belt is perfectly fine and so are the gears that the belt latches onto. The Gear that gets turned by the dome's rotation, which then turns the motor that measures the rotation, also seems fine. The problem now seems to only be the motor itself, or the gearing system.
   1. We can prove the gearing system being at fault if we can measure the % difference of the azimuths when starting at a fixed point. We will do this by slewing the telescope into some arbitrary azimuth/angle number (will call this number d), with starting point 0. The dome will be manually slewed into the correct position over the telescope (while the telescope is still at 0 azimuth). Now we will slew the dome over the new telescope position and we measure the percent difference in their azimuths (don't forget to count full circle rotations too if the total in rotations is bigger than 360°). Repeat a couple times.
   2. I know that this could mean that there is either a gearing problem or possibly a hall effect sensor problem in the motor.

   3. These are some more experiments that I did. I will not continue them today as they are taking a long time since I'm by myself

      rotation#	Scope Azimuth	Dome Azimuth	Scope %	Scope%to Dome%	Dome  %
      0	0	45.8	-		-
      1	30.0	72.9			0.6282
      2	60.0	111.2	0.5	0.7959	0.6555
      3	92.9	148.2	0.6666	0.8884	0.7503
      4	120.0	175.8	0.75	0.8896	0.8430

BIG NOTE: issue is fixed, the problem was caused due to the plastic gear which was driven by the dome's rotation (and connected to the motor) not having its screw securely tightened.  I tightened it and then aligned the scope with the dome. Then I went into DFMTCS → Telescope → Initialization → Other positions and then set the dome azimuth to the scope's azimuth. The tracking is off very slightly to the right side by a negligible amount (the scope is still almost centered), but it remained the same on all of my many tests.  I believe this might be due to my own imperfect calibration, but it still shouldn't be a problem. 

NOTE: HALT MOTORS BUTTON MIGHT BE MALPHUNCTIONING; I PRESSED IT TO SEE IF IT ACTUALLY WORKED AND THE SLEWING STOPPED FOR A SECOND AND THEN SPED UP MORE THAN BEFORE (???). It is possible that it only seemed to me that it sped up, but the motor pitch seemed to increase. The slewing didn't stop though, but the cancel button or cancel command both work.

NOTE: When slewing the telescope there seem to be some azimuth ranges that it skips over. The one I discovered is 87.1-92.9 (I don't seem to be able to slew the telescope in any of the values in between). If this is an actual issue, could this be causing problems like that?

NOTE: THE DOME DOORS WERE CLOSED FOR THE ENTIRE DURATION AND EVERY TRY WAS RECORDED FROM THE CAMERA. THE VIDEO FILE CAN BE FOUND EITHER IN BLUE IRIS OR C:\BlueIris\New

TODO: 

1. Test the dome tracking again, in case every attempt was a fluke (unlikely)

Attendance: Gabriel

Date/Time: 12/12/2022, 11:20-14:15

Spaces Occupied: Control Room, Dome

Goals: 

1. Slave dome to scope (accurately)

Log:

1. Set-up a camera in the dome to be able to monitor how the dome and scope are behaving.
2. TCS buttons:
   1. Halt-motors - off
   2. MTR DRIVE CHASSIS - on
   3. Drives - on
   4. auto-dome - off
   5. external computer - on
   6. dome track - on
3. On ASCOM dome control:
   1. Press "Connect" 
   2. Selected "Slave to dome"
      1. (WONT WORK WITHOUT THIS OPTION)

FIRST TEST:

1. Opened TheSky6
   1. Established link with telescope
   2. Selected position in north sky "RA: 17h 27m 52s Dec: +72°09'51""
   3. Slew successful, dome doesn't respond without the Autodome switch on on position
   4. With autodome switch "on", the dome rotates past the telescope pointing by around 280-290°

SECOND TEST:

1. Enabled both AUTO DOME and DOME TRACK switches
2. Dome Correctly followed telescope pointing.

THIRD TEST: 

1. With the previous settings, slewing the telescope to "RA: 15h 03m 53s Dec: +64°21'44"
2. Scope completes rotation 
3. Dome waits a small amount of time and then rotates.
4. Dome rotation is off by a very small amount to the right, probably 2-3°

Note: In C:\Program Files\ASCOM\Platform 6\Tools there exist interesting tools, like the profile explorer. There are a couple of profiles, we will try using POTH Dome because it seems to have more configuration options.

In ASCOM Dome control:

1. Go to setup
2. Select Dome (POTH (stands for Plain Old Telescope Handset))

Look out for this file: "ASCOM.Diagnostics.1918.589350", it has useful data

NOTE: POINTING IS OFF , slewed to zenith but the movement wasn't completed, slewed to Altair and the scope is pointing close to zenith, (Altair isn't at zenith)

NOTE: I am suspecting that the offset of the dome might be caused due to bad pointing by the telescope. Pointing got worse the more I slewed the telescope, and so did dome tracking.  Haven't done tests to confirm yet.

NOTE: THE DOME DOORS WERE CLOSED FOR THE ENTIRE DURATION AND EVERY TRY WAS RECORDED FROM THE CAMERA. THE VIDEO FILE CAN BE FOUND EITHER IN BLUE IRIS OR C:\BlueIris\New

TODO:

1. Calibrate pointing
2. Calibrate dome (after pointing is calibrated)
3. Check out fiducials email (forward the email Roy)
4. Then we happy always (maybe)

Attendance (Open House): approx. 40

Attendance (Astro Club + Obs Core): Natalie, Roy, Tara, Matt, Onkar

Date & Time 12/8/22 6:00-8:00 PM

Spaces Occupied: 401, Control Room, Dome

Achievements

1. Astro/Core except onkar arrived at 5:00PM, RSA arrived 5:30PM
2. RSA brought snacks, decorations, slime making, oobleck
3. onkar arrived at 6:45
   1. way to be late forehead
4. People started showing up at 6:00
5. Speaker arrived at 6:15
6. guests did activities till 6:30
7. began tours approx when onkar arrived (6:45)
   1. onkar in warm room
   2. tara, matt, nat, in dome
      1. dont get confused
   3. roy bouncing between dome and warm
   4. katie (not astro pol the other one) helped make groups
8. stopped tours approx 7:30, speaker began
9. speaker spoke, very nice, ended approx. 8:20
   1. he was very satisfied -roy
   2. also gave him sick goodie bag
10. transitioned into astro club movie night
11. cleaning was a bitch

Notes/ToDo

1. gam and baffle return pls
2. need to send thank you email to Dr. Kevin Lewis (speaker)
3. RSA communication could be a little better, clear communication and collaboration for the events in the future would be optimal
   1. follow up email maybe? -natalie

Attendance (Open House): 14

Attendance (Observing Group): Onkar Roy Jackson Tara

Date & Time: 12/1/22 7:00-9:00PM

Spaces Occupied: 401, Control Room, Dome

Achievements

1. gave coherent talk on space -roy
2. gave a mostly correct description of war(m) room operations -onkar
3. took 6-7 folks to the dome and showed the the primary mirror, secondary mirror and where the gam is supposed to go lol -jackson

Notes/ToDo/Wishlist

1. color/colorwheel cmos
2. gam or gam like object back installed
3. also tube baffle thing that would be helpful for observing

Open House Notes:

1. standard open house -tara

Attendance Onkar, Gabriel, Shreyansh, Nathan, Meyer, Eric, Roy

Date/Time 12/01/22 12:00-6:00PM

Spaces Occupied: 401, Control Room, Dome

Goals

1. Remove panel for GAM for attaching motor stepper control (Thor)

Other Notes

      How we got there

1. Onkar engaged motors to slew telescope south to expose GAM for easier access to Erik
2. Scope didn't stop at predetermined location communicated by TheSky6
   1. TS6: Crosshairs went past target position and continued moving South
   2. Eileen/Erik tried to get Onkar to stop the motors
   3. "HALT MOTORS" button being IN didn't stop motors
   4. Disengaging "DRIVES" switch also didn't stop the motors
   5. Disengaging "MTR DRIVER CHASSIS" switch DID stop the motors
      1. at this point, fork was bonked by scope so its unclear whether disengaging the previous OR scope fork bonking stopped motion
3. We don't know why this happened.
4. And we couldn't issue further commands to right the telescope
   1. No TCS commands worked
   2. No hand paddle commands worked
   3. No slew commands issued through TS6 worked
5. We aren't SURE, but it seems like the motors would continue to drive if we re-engaged the "DRIVES" and "MTR DRIVER CHASSIS"
   1. We heard a humming sound

      How we fixt it

1. At some point in the above, the "HORIZON LIMIT" LED light went off, interrupting power to the motors
   1. Per "2.3 LIMIT SWITCH" in DFM_Telescope_Manual.pdf on Desktop of DC
2. Before identifying this as the issue, we confirmed that the fuses on the TCS Chassis were good and power cycled TS6 and DFM TCS Software and entire TCS Computer
3. Again, per "2.3 LIMIT SWITCH" in the manual, Erik and Onkar physically pushed the telescope above the horizon with all three switches/buttons disengaged.
   1. In this state, any movement upward wasn't held in place by the motors
4. After "DRIVES" and "MTR DRIVER CHASSIS" were engaged, the telescope was held in place as Onkar and Erik physically pushed the scope above the horizon
   1. Concurrently, the "HORIZON LIMIT" LED light came back on.
5. After the "HORIZON LIMIT" LED was back on, we could issue motor commands from the TCS.
6. We manually moved the telescope to zenith and stowed.
7. TS6 still doesn't report the correct position of the telescope when the link is established.

Todos

• Figure out why this happened
• Figure out what the "HALT MOTORS" button does
• Figure out what the "DRIVES" switch does
• Figure out what the "MTR DRIVER CHASSIS" switch does
• (Consult the manual)