DEC guiding problem (gear?) AM5 within 1hour before MF

chrjaeger

Hi,
has anybody had this problem as well?
I use an AM5, TS CFAPO90 with 0.8 reducer (focal lenght 432mm), ASI 2600MM, ASIAIR PLUS, no counter weight (less than 10 kg)
guiding camera at separate 160mm guide scope: ASI 462 MC with L filter

I constantly have the problem that within 1 hour before MF the DEC axis is lost (star lost .... mass changed). As a result ASIAIR selects obviously another guide star and stabilizes, though the image is shifted. It looks as if the telescope moves South by a constant amount (typical 5% ... 10% of FOV) and stays then constant. This may happen several times. An example ist shown in the figure showing two ghost images. North is to the left.... I have a lot more examples.

https://ibb.co/7RtMmn6

Before that failure and AFTER MF everything is fine, images are at their suggested coordinates (Autorun, Plan).

In the following I put sections of the logs. The PHD2 parts clearly show, that ASIAIR guiding tries hard to shift the telescope north immediately before, but it fails. It looks as if the guide star moves out of the box.... S/N of the ASI462MC is not the problem. I suspect a gear issue... Any comments and replies, ZWO too..

Log enabled at 2023/09/26 19:53:22
2023/09/26 19:53:22 [Autorun|Begin] ruchba Start
2023/09/26 19:53:22 Target RA:20h30m45s DEC:+49Â°1'31"
2023/09/26 19:53:22 Shooting 10 light frames, exposure 900.0s Bin2
2023/09/26 19:53:22 Start Tracking
2023/09/26 19:53:22 [Guide] Stop Guiding
2023/09/26 19:53:22 [AutoFocus|Begin] Run AF before Autorun start, exposure 3.0s Bin1, temperature 21.9â„ƒ
2023/09/26 19:53:22 Find Focus Star
2023/09/26 19:53:31 Find Focus Star: detect and calculate star size 2.4 , EAF position 9324
2023/09/26 19:53:31 Find Focus Star: finding appropriate stars star size 2.4
2023/09/26 19:53:50 Find Focus Star: detect and calculate star size 12.2 , EAF position 10824
2023/09/26 19:53:50 Calculate V-Curve
2023/09/26 19:53:58 Calculate V-Curve: detect and calculate star size 12.7 , EAF position 10824
2023/09/26 19:54:08 Calculate V-Curve: detect and calculate star size 11.2 , EAF position 10624
2023/09/26 19:54:18 Calculate V-Curve: detect and calculate star size 9.2 , EAF position 10424
2023/09/26 19:54:27 Calculate V-Curve: detect and calculate star size 7.3 , EAF position 10224
2023/09/26 19:54:37 Calculate V-Curve: detect and calculate star size 6.0 , EAF position 10024
2023/09/26 19:54:47 Calculate V-Curve: detect and calculate star size 4.5 , EAF position 9824
2023/09/26 19:54:57 Calculate V-Curve: detect and calculate star size 2.7 , EAF position 9424
2023/09/26 19:55:06 Calculate V-Curve: detect and calculate star size 2.4 , EAF position 9224
2023/09/26 19:55:16 Calculate V-Curve: detect and calculate star size 2.7 , EAF position 9024
2023/09/26 19:55:26 Calculate V-Curve: detect and calculate star size 3.6 , EAF position 8824
2023/09/26 19:55:35 Calculate V-Curve: detect and calculate star size 4.7 , EAF position 8624
2023/09/26 19:55:45 Calculate V-Curve: detect and calculate star size 6.5 , EAF position 8424
2023/09/26 19:55:55 Find Focus Point
2023/09/26 19:56:03 Calculate Focus Point: detect and calculate star size 3.7 , EAF position 9605
2023/09/26 19:56:12 Calculate Focus Point: detect and calculate star size 3.3 , EAF position 9505
2023/09/26 19:56:22 Calculate Focus Point: detect and calculate star size 2.9 , EAF position 9405
2023/09/26 19:56:31 Calculate Focus Point: detect and calculate star size 2.6 , EAF position 9305
2023/09/26 19:56:40 Calculate Focus Point: detect and calculate star size 2.4 , EAF position 9205
2023/09/26 19:56:40 Auto focus succeeded, the focused position is 9205
2023/09/26 19:56:40 [AutoFocus|End] Auto focus succeeded
2023/09/26 19:56:42 [Guide] ReSelect Guide star
2023/09/26 19:56:43 [Guide] Start Guiding
2023/09/26 19:56:44 [Guide] Guide Settle
2023/09/26 19:56:47 [Guide] Settle Done
2023/09/26 19:56:47 Exposure 900.0s image 1#
2023/09/26 20:05:43 Stop Autorun Manually
2023/09/26 20:05:43 [Autorun|End] Pause Autorun
Log disabled at 2023/09/26 20:05:43
Log enabled at 2023/09/26 20:05:55
2023/09/26 20:05:55 [Autorun|Begin] ruchba Start
2023/09/26 20:05:55 Target RA:20h30m51s DEC:+49Â°1'31"
2023/09/26 20:05:55 Shooting 10 light frames, exposure 900.0s Bin2
2023/09/26 20:05:55 Start Tracking
2023/09/26 20:05:55 [Guide] Stop Guiding
2023/09/26 20:05:55 [AutoFocus|Begin] Run AF before Autorun start, exposure 3.0s Bin1, temperature 21.4â„ƒ
2023/09/26 20:05:55 Find Focus Star
2023/09/26 20:06:04 Find Focus Star: detect and calculate star size 2.4 , EAF position 9205
2023/09/26 20:06:04 Find Focus Star: finding appropriate stars star size 2.4
2023/09/26 20:06:24 Find Focus Star: detect and calculate star size 11.5 , EAF position 10705
2023/09/26 20:06:24 Calculate V-Curve
2023/09/26 20:06:33 Calculate V-Curve: detect and calculate star size 12.2 , EAF position 10705
2023/09/26 20:06:42 Calculate V-Curve: detect and calculate star size 10.0 , EAF position 10505
2023/09/26 20:06:53 Calculate V-Curve: detect and calculate star size 9.2 , EAF position 10305
2023/09/26 20:07:03 Calculate V-Curve: detect and calculate star size 7.2 , EAF position 10105
2023/09/26 20:07:13 Calculate V-Curve: detect and calculate star size 6.2 , EAF position 9905
2023/09/26 20:07:23 Calculate V-Curve: detect and calculate star size 4.7 , EAF position 9705
2023/09/26 20:07:33 Calculate V-Curve: detect and calculate star size 2.8 , EAF position 9305
2023/09/26 20:07:43 Calculate V-Curve: detect and calculate star size 2.4 , EAF position 9105
2023/09/26 20:07:53 Calculate V-Curve: detect and calculate star size 2.6 , EAF position 8905
2023/09/26 20:08:02 Calculate V-Curve: detect and calculate star size 3.4 , EAF position 8705
2023/09/26 20:08:13 Calculate V-Curve: detect and calculate star size 4.5 , EAF position 8505
2023/09/26 20:08:23 Calculate V-Curve: detect and calculate star size 6.0 , EAF position 8305
2023/09/26 20:08:33 Calculate V-Curve: detect and calculate star size 7.5 , EAF position 8105
2023/09/26 20:08:43 Find Focus Point
2023/09/26 20:08:52 Calculate Focus Point: detect and calculate star size 4.1 , EAF position 9528
2023/09/26 20:09:01 Calculate Focus Point: detect and calculate star size 3.6 , EAF position 9428
2023/09/26 20:09:11 Calculate Focus Point: detect and calculate star size 3.2 , EAF position 9328
2023/09/26 20:09:20 Calculate Focus Point: detect and calculate star size 2.8 , EAF position 9228
2023/09/26 20:09:29 Calculate Focus Point: detect and calculate star size 2.5 , EAF position 9128
2023/09/26 20:09:29 Auto focus succeeded, the focused position is 9128
2023/09/26 20:09:30 [AutoFocus|End] Auto focus succeeded
2023/09/26 20:09:31 [Guide] ReSelect Guide star
2023/09/26 20:09:32 [Guide] Start Guiding
2023/09/26 20:09:33 [Guide] Guide Settle
2023/09/26 20:09:37 [Guide] Settle Done
2023/09/26 20:09:37 Exposure 900.0s image 1#
2023/09/26 20:24:38 [Guide] Dither
2023/09/26 20:24:38 [Guide] Dither Settle
2023/09/26 20:24:48 [Guide] Settle Done
2023/09/26 20:24:48 Exposure 900.0s image 2#
2023/09/26 20:39:49 [Guide] Dither
2023/09/26 20:39:49 [Guide] Dither Settle
2023/09/26 20:40:14 [Guide] Settle Done
2023/09/26 20:40:14 Exposure 900.0s image 3#
2023/09/26 20:55:16 [Guide] Dither
2023/09/26 20:55:16 [Guide] Dither Settle
2023/09/26 20:55:30 [Guide] Settle Done

2023/09/26 20:55:30 Exposure 900.0s image 4#
2023/09/26 20:57:03 [Guide] Guide star lost
twice: Guide Star loss (mass changed, c.f. below in PHD2 section,
2023/09/26 20:57:04 [Guide] ReSelect Guide star
2023/09/26 20:57:05 [Guide] Start Guiding
2023/09/26 21:06:49 [Guide] Guide star lost
happened 32 min and 19 min before MF, two ghost (shifted pictures)

2023/09/26 21:06:51 [Guide] ReSelect Guide star
2023/09/26 21:06:51 [Guide] Start Guiding
2023/09/26 21:10:32 [Guide] Dither
2023/09/26 21:10:32 [Guide] Dither Settle
2023/09/26 21:10:58 [Guide] Settle Done
2023/09/26 21:10:58 [Guide] Stop Guiding
2023/09/26 21:10:58 Stop Tracking
2023/09/26 21:10:58 [Meridian Flip|Begin] Wait 14min5s to Meridian Flip
2023/09/26 21:25:03 Meridian Flip 1# Start
2023/09/26 21:25:03 [AutoCenter|Begin] Auto-Center 1#
2023/09/26 21:25:03 Mount slews to target position: RA:20h30m51s DEC:+49Â°1'31"
2023/09/26 21:25:34 Exposure 5.0s
2023/09/26 21:25:40 Plate Solve
2023/09/26 21:25:42 Solve succeeded: RA:20h33m11s DEC:+49Â°22'35" Angle = 89.962, Star number = 626
2023/09/26 21:25:42 [AutoCenter|End] Too far from center, distance = 24%(0.51769Â°)
2023/09/26 21:25:44 [AutoCenter|Begin] Auto-Center 2#
2023/09/26 21:25:44 Mount slews to target position: RA:20h30m51s DEC:+49Â°1'31"
2023/09/26 21:25:45 Exposure 5.0s
2023/09/26 21:25:51 Plate Solve
2023/09/26 21:25:54 Solve succeeded: RA:20h30m52s DEC:+49Â°1'43" Angle = 89.8319, Star number = 638
2023/09/26 21:25:54 [AutoCenter|End] The target is centered
2023/09/26 21:25:54 [Meridian Flip|End] Meridian Flip succeeded
2023/09/26 21:25:54 Start Tracking
2023/09/26 21:25:54 Wait for Mount Settle
2023/09/26 21:25:59 Start Tracking
2023/09/26 21:25:59 [AutoFocus|Begin] Run AF after Auto Meridian filpped, exposure 3.0s Bin1, temperature 19.6â„ƒ
2023/09/26 21:25:59 Find Focus Star
2023/09/26 21:26:07 Find Focus Star: detect and calculate star size 2.4 , EAF position 9128
2023/09/26 21:26:08 Find Focus Star: finding appropriate stars star size 2.4
2023/09/26 21:26:27 Find Focus Star: detect and calculate star size 12.5 , EAF position 10628
2023/09/26 21:26:27 Calculate V-Curve
2023/09/26 21:26:35 Calculate V-Curve: detect and calculate star size 13.2 , EAF position 10628
2023/09/26 21:26:45 Calculate V-Curve: detect and calculate star size 10.7 , EAF position 10428
2023/09/26 21:26:55 Calculate V-Curve: detect and calculate star size 9.1 , EAF position 10228
2023/09/26 21:27:05 Calculate V-Curve: detect and calculate star size 7.4 , EAF position 10028
2023/09/26 21:27:14 Calculate V-Curve: detect and calculate star size 5.8 , EAF position 9828
2023/09/26 21:27:24 Calculate V-Curve: detect and calculate star size 4.5 , EAF position 9628
2023/09/26 21:27:34 Calculate V-Curve: detect and calculate star size 3.5 , EAF position 9428
2023/09/26 21:27:44 Calculate V-Curve: detect and calculate star size 2.7 , EAF position 9228
2023/09/26 21:27:54 Calculate V-Curve: detect and calculate star size 2.4 , EAF position 9028
2023/09/26 21:28:04 Calculate V-Curve: detect and calculate star size 2.7 , EAF position 8828
2023/09/26 21:28:14 Calculate V-Curve: detect and calculate star size 3.8 , EAF position 8628
2023/09/26 21:28:24 Calculate V-Curve: detect and calculate star size 4.8 , EAF position 8428
2023/09/26 21:28:34 Calculate V-Curve: detect and calculate star size 6.4 , EAF position 8228
2023/09/26 21:28:44 Find Focus Point
2023/09/26 21:28:52 Calculate Focus Point: detect and calculate star size 4.2 , EAF position 9468
2023/09/26 21:29:01 Calculate Focus Point: detect and calculate star size 3.7 , EAF position 9368
2023/09/26 21:29:11 Calculate Focus Point: detect and calculate star size 3.1 , EAF position 9268
2023/09/26 21:29:20 Calculate Focus Point: detect and calculate star size 2.8 , EAF position 9168
2023/09/26 21:29:29 Calculate Focus Point: detect and calculate star size 2.5 , EAF position 9068
2023/09/26 21:29:29 Auto focus succeeded, the focused position is 9068
2023/09/26 21:29:30 [AutoFocus|End] Auto focus succeeded
2023/09/26 21:29:31 [Guide] ReSelect Guide star
2023/09/26 21:29:32 [Guide] Start Calibrating
2023/09/26 21:30:51 [Guide] Calibrate Success
2023/09/26 21:30:51 [Guide] Guide Settle
2023/09/26 21:31:03 [Guide] Settle Done
2023/09/26 21:31:03 Exposure 900.0s image 5#
2023/09/26 21:46:05 [Guide] Dither
2023/09/26 21:46:05 [Guide] Dither Settle
2023/09/26 21:46:14 [Guide] Settle Done
2023/09/26 21:46:14 Exposure 900.0s image 6#
2023/09/26 21:46:22 Stop Autorun Manually
2023/09/26 21:46:23 [Autorun|End] Pause Autorun
Log disabled at 2023/09/26 21:46:23

c.f. image 4 before MF : 2 additional „ghost“ images

PHD2: log file messages,

before problem occurs; DEC corrections increase, but cannot compensate DEC issue, star moves obviously out of box , star lost......

after selecting new guide star: neutral guiding until next case....,, Image shifted though

AFTER MF: everything is normal, image is not shiftet any more, corresponds to chosen image RA/DEC image coordinates when starting AUTORUN or PLAN

jump:
********************************************************************************************************************************************************************
5646,2834.626,"Mount",0.228,0.407,0.088,-0.458,0.000,-0.183,0,,46,N,,,3397,41.00,0
5647,2835.149,"Mount",0.401,0.448,0.238,-0.550,0.075,-0.220,27,W,55,N,,,3604,42.16,0
5648,2835.658,"Mount",0.439,0.388,0.293,-0.505,0.095,-0.202,34,W,51,N,,,3459,41.27,0
5649,2836.131,"Mount",0.256,0.446,0.102,-0.503,0.035,-0.201,13,W,50,N,,,3476,41.46,0
5650,2836.631,"Mount",0.095,0.398,-0.037,-0.408,0.000,-0.163,0,,41,N,,,3428,41.17,0
5651,2837.131,"Mount",0.209,0.517,0.034,-0.556,0.000,-0.222,0,,56,N,,,3432,41.23,0
5652,2837.639,"Mount",0.221,0.600,0.019,-0.639,0.000,-0.255,0,,64,N,,,3458,41.35,0
5653,2838.128,"Mount",0.217,0.484,0.052,-0.528,0.000,-0.211,0,,53,N,,,3386,40.91,0
5654,2838.647,"Mount",0.126,0.400,-0.007,-0.420,0.000,-0.168,0,,42,N,,,3547,41.90,0
5655,2839.071,"Mount",0.006,-0.024,0.013,0.021,0.000,0.000,0,,0,,,,3485,41.50,0
5656,2839.570,"Mount",-0.133,-0.176,-0.071,0.209,0.000,0.000,0,,0,,,,3578,42.09,0
5657,2840.077,"Mount",-0.090,-0.210,-0.018,0.227,0.000,0.000,0,,0,,,,3443,41.26,0
5658,2840.569,"Mount",-0.020,-0.092,0.010,0.094,0.000,0.000,0,,0,,,,3499,41.64,0
5659,2841.077,"Mount",0.071,-0.061,0.087,0.036,0.000,0.000,0,,0,,,,3465,41.44,0
5660,2841.606,"Mount",0.174,0.186,0.106,-0.231,0.033,-0.092,12,W,23,N,,,3421,41.10,0
5661,2842.166,"Mount",0.396,0.521,0.210,-0.619,0.067,-0.247,24,W,62,N,,,3492,41.48,0
5662,2842.686,"Mount",0.481,0.746,0.219,-0.858,0.071,-0.343,25,W,86,N,,,3468,41.35,0
5663,2843.216,"Mount",0.592,1.146,0.198,-1.273,0.065,-0.509,23,W,127,N,,,3567,42.01,0
5664,2843.723,"Mount",0.579,1.440,0.092,-1.549,0.000,-0.620,0,,150,N,,,3455,41.33,0
5665,2844.264,"Mount",0.599,1.924,-0.043,-2.015,0.000,-0.806,0,,150,N,,,3552,41.90,0
5666,2844.708,"Mount",0.907,2.522,0.059,-2.679,0.000,-1.071,0,,150,N,,,3534,41.75,0
5667,2845.251,"Mount",2.098,5.058,0.384,-5.459,0.121,-2.184,43,W,150,N,,,3541,41.75,0
5668,2845.805,"Mount",4.590,11.102,0.828,-11.978,0.265,-4.791,94,W,150,N,,,2304,33.49,0
5669,2846.009,"DROP",,,,,,,,,,,,,696,18.22,6,"Star lost - mass changed"
5670,2846.506,"DROP",,,,,,,,,,,,,111,7.28,6,"Star lost - mass changed"
5671,2847.008,"DROP",,,,,,,,,,,,,206,9.89,6,"Star lost - mass changed"
5672,2847.538,"DROP",,,,,,,,,,,,,232,10.77,6,"Star lost - mass changed"
5673,2848.009,"DROP",,,,,,,,,,,,,241,10.98,6,"Star lost - mass changed"
5674,2848.527,"DROP",,,,,,,,,,,,,222,10.54,6,"Star lost - mass changed"
5675,2849.012,"DROP",,,,,,,,,,,,,232,10.77,6,"Star lost - mass changed"
5676,2849.538,"DROP",,,,,,,,,,,,,211,10.03,6,"Star lost - mass changed"
5677,2850.007,"DROP",,,,,,,,,,,,,215,10.37,6,"Star lost - mass changed"
5678,2850.510,"DROP",,,,,,,,,,,,,229,10.70,6,"Star lost - mass changed"
Guiding Ends at 2023-09-26 20:57:03

Guiding Begins at 2023-09-26 20:57:05
Dither = both axes, Dither scale = 1.000, Image noise reduction = none, Guide-frame time lapse = 0, Server enabled
Pixel scale = 3.74 arc-sec/px, Binning = 1, Focal length = 160 mm
Search region = 50 px, Star mass tolerance = 50.0%
Equipment Profile =
Camera = ZWO ASI462MC, gain = 116, full size = 1936 x 1096, no dark, no defect map, pixel size = unspecified
Exposure = 500 ms
Mount = ZWO AM5, connected, guiding enabled, xAngle = -18.5, xRate = 2.807, yAngle = -108.9, yRate = 3.995, parity = ?/?,
X guide algorithm = Hysteresis, Hysteresis = 0.100, Aggression = 0.350, Minimum move = 0.100
Y guide algorithm = Resist Switch, Minimum move = 0.100 Aggression = 40% FastSwitch = enabled
Backlash comp = disabled, pulse = 0 ms
Calibration step = phdlab_placeholder, Max RA duration = 150, Max DEC duration = 150, DEC guide mode = Auto
RA Guide Speed = Unknown, Dec Guide Speed = Unknown, Cal Dec = 49.0, Last Cal Issue = None, Timestamp = Unknown
Dec = 49.0 deg, Hour angle = -0.44 hr, Pier side = West, Rotator pos = N/A
Lock position = 1130.984, 683.561, Star position = 1131.291, 683.774, HFD = 6.27 px
Frame,Time,mount,dx,dy,RARawDistance,DECRawDistance,RAGuideDistance,DECGuideDistance,RADuration,RADirection,DECDuration,DECDirection,XStep,YStep,StarMass,SNR,ErrorCode
INFO: SETTLING STATE CHANGE, Settling started
1,0.572,"Mount",0.223,0.416,0.079,-0.465,0.000,-0.186,0,,47,N,,,3444,41.26,0 from here: normal guiding
2,1.130,"Mount",0.205,0.411,0.063,-0.454,0.000,-0.182,0,,46,N,,,3492,41.57,0
3,1.593,"Mount",-0.013,0.494,-0.169,-0.465,-0.053,-0.186,19,E,47,N,,,3544,41.87,0
4,2.142,"Mount",-0.042,0.438,-0.179,-0.403,-0.058,-0.161,21,E,40,N,,,3397,41.00,0
5,2.571,"Mount",0.198,0.420,0.055,-0.461,0.000,-0.184,0,,46,N,,,3406,41.03,0
6,3.081,"Mount",0.191,0.175,0.125,-0.226,0.040,-0.090,14,W,23,N,,,3461,41.29,0
INFO: SETTLING STATE CHANGE, Settling complete
7,3.561,"Mount",0.099,0.344,-0.015,-0.358,0.000,-0.143,0,,36,N,,,3775,43.25,0
8,4.109,"Mount",0.005,0.255,-0.076,-0.244,0.000,-0.097,0,,24,N,,,3489,41.60,0
9,4.563,"Mount",0.122,0.220,0.046,-0.247,0.000,-0.099,0,,25,N,,,3415,41.12,0
10,5.095,"Mount",-0.032,0.091,-0.059,-0.076,0.000,0.000,0,,0,,,,3490,41.46,0
11,5.575,"Mount",0.306,0.104,0.257,-0.193,0.081,-0.077,29,W,19,N,,,3510,41.63,0
12,6.110,"Mount",0.202,-0.159,0.242,0.088,0.079,0.000,28,W,0,,,,3600,42.25,0
13,6.555,"Mount",0.128,-0.254,0.202,0.202,0.067,0.000,24,W,0,,,,3405,40.80,0
14,7.032,"Mount",-0.031,-0.104,0.004,0.108,0.000,0.000,0,,0,,,,3555,41.94,0
15,7.526,"Mount",-0.037,-0.261,0.047,0.260,0.000,0.000,0,,0,,,,3553,41.75,0
16,8.058,"Mount",-0.067,-0.160,-0.012,0.173,0.000,0.000,0,,0,,,,3448,41.10,0
17,8.555,"Mount",-0.115,-0.028,-0.100,0.062,-0.032,0.000,11,E,0,,,,3579,42.07,0
18,9.083,"Mount",-0.156,-0.003,-0.147,0.051,-0.047,0.000,17,E,0,,,,3698,42.77,0
19,9.541,"Mount",-0.071,-0.054,-0.050,0.073,0.000,0.000,0,,0,,,,3546,41.87,0
20,10.096,"Mount",-0.060,-0.110,-0.022,0.124,0.000,0.049,0,,12,S,,,3626,42.32,0
21,10.557,"Mount",-0.060,-0.139,-0.013,0.150,0.000,0.060,0,,15,S,,,3705,42.81,0
22,11.066,"Mount",0.008,-0.105,0.041,0.097,0.000,0.000,0,,0,,,,3640,42.44,0
23,11.537,"Mount",0.006,-0.079,0.031,0.073,0.000,0.000,0,,0,,,,3595,42.20,0
24,12.092,"Mount",0.044,-0.175,0.097,0.153,0.000,0.061,0,,15,S,,,3515,41.40,0

jump:

1136,568.135,"Mount",-0.005,-0.040,0.008,0.039,0.000,0.000,0,,0,,,,3692,42.70,0
1137,568.691,"Mount",0.071,-0.031,0.078,0.008,0.000,0.000,0,,0,,,,3657,42.48,0
1138,569.135,"Mount",-0.029,0.026,-0.036,-0.016,0.000,0.000,0,,0,,,,3770,43.09,0
1139,569.716,"Mount",-0.065,0.169,-0.115,-0.140,-0.036,-0.056,13,E,14,N,,,3689,42.71,0
1140,570.165,"Mount",-0.151,0.162,-0.194,-0.107,-0.062,-0.043,22,E,11,N,,,3612,42.26,0
1141,570.652,"Mount",0.157,0.047,0.134,-0.094,0.040,0.000,14,W,0,,,,3622,42.26,0
1142,571.159,"Mount",0.148,0.078,0.116,-0.120,0.038,-0.048,13,W,12,N,,,3862,43.63,0
1143,571.696,"Mount",0.036,0.263,-0.049,-0.261,0.000,-0.105,0,,26,N,,,3662,42.59,0
1144,572.148,"Mount",-0.017,0.113,-0.053,-0.102,0.000,-0.041,0,,10,N,,,3679,42.59,0
1145,572.697,"Mount",-0.119,0.159,-0.163,-0.114,-0.051,-0.046,18,E,11,N,,,3714,42.89,0
1146,573.171,"Mount",-0.062,0.232,-0.132,-0.201,-0.043,-0.081,15,E,20,N,,,3802,43.37,0
1147,573.703,"Mount",0.086,0.185,0.022,-0.202,0.000,-0.081,0,,20,N,,,3749,43.09,0
1148,574.177,"Mount",0.206,0.205,0.130,-0.259,0.041,-0.104,15,W,26,N,,,3830,43.59,0
1149,574.728,"Mount",0.246,0.300,0.139,-0.361,0.045,-0.144,16,W,36,N,,,3731,42.98,0
1150,575.166,"Mount",0.107,0.191,0.041,-0.215,0.000,-0.086,0,,22,N,,,3869,43.72,0
1151,575.708,"Mount",0.030,0.171,-0.026,-0.171,0.000,-0.069,0,,17,N,,,3812,43.44,0
1152,576.199,"Mount",0.302,0.244,0.208,-0.326,0.066,-0.130,23,W,33,N,,,3815,43.46,0
1153,576.796,"Mount",0.488,0.617,0.267,-0.737,0.086,-0.295,31,W,74,N,,,3779,43.18,0
1154,577.215,"Mount",0.259,0.774,0.000,-0.817,0.000,-0.327,0,,82,N,,,3796,43.26,0
1155,577.748,"Mount",0.299,1.009,-0.036,-1.052,0.000,-0.421,0,,105,N,,,3693,42.66,0
1156,578.308,"Mount",0.323,1.421,-0.144,-1.451,-0.046,-0.580,16,E,145,N,,,3783,43.13,0
1157,578.783,"Mount",1.276,3.908,-0.030,-4.111,0.000,-1.644,0,,150,N,,,1910,30.14,0
1158,579.080,"DROP",,,,,,,,,,,,,246,11.09,6,"Star lost - mass changed"
1159,579.581,"DROP",,,,,,,,,,,,,243,11.02,6,"Star lost - mass changed"
1160,580.089,"DROP",,,,,,,,,,,,,245,11.07,6,"Star lost - mass changed"
1161,580.584,"DROP",,,,,,,,,,,,,254,11.27,6,"Star lost - mass changed"
1162,581.119,"DROP",,,,,,,,,,,,,245,11.07,6,"Star lost - mass changed"
1163,581.583,"DROP",,,,,,,,,,,,,252,11.22,6,"Star lost - mass changed"
1164,582.120,"DROP",,,,,,,,,,,,,246,11.09,6,"Star lost - mass changed"
1165,582.582,"DROP",,,,,,,,,,,,,252,11.22,6,"Star lost - mass changed"
1166,583.084,"DROP",,,,,,,,,,,,,257,11.34,6,"Star lost - mass changed"
1167,583.582,"DROP",,,,,,,,,,,,,242,11.00,6,"Star lost - mass changed"
Guiding Ends at 2023-09-26 21:06:49

Guiding Begins at 2023-09-26 21:06:52
Dither = both axes, Dither scale = 1.000, Image noise reduction = none, Guide-frame time lapse = 0, Server enabled
Pixel scale = 3.74 arc-sec/px, Binning = 1, Focal length = 160 mm
Search region = 50 px, Star mass tolerance = 50.0%
Equipment Profile =
Camera = ZWO ASI462MC, gain = 116, full size = 1936 x 1096, no dark, no defect map, pixel size = unspecified
Exposure = 500 ms
Mount = ZWO AM5, connected, guiding enabled, xAngle = -18.5, xRate = 2.807, yAngle = -108.9, yRate = 3.995, parity = ?/?,
X guide algorithm = Hysteresis, Hysteresis = 0.100, Aggression = 0.350, Minimum move = 0.100
Y guide algorithm = Resist Switch, Minimum move = 0.100 Aggression = 40% FastSwitch = enabled
Backlash comp = disabled, pulse = 0 ms
Calibration step = phdlab_placeholder, Max RA duration = 150, Max DEC duration = 150, DEC guide mode = Auto
RA Guide Speed = Unknown, Dec Guide Speed = Unknown, Cal Dec = 49.0, Last Cal Issue = None, Timestamp = Unknown
Dec = 49.0 deg, Hour angle = -0.28 hr, Pier side = West, Rotator pos = N/A
Lock position = 853.148, 552.833, Star position = 853.365, 552.819, HFD = 5.32 px
Frame,Time,mount,dx,dy,RARawDistance,DECRawDistance,RAGuideDistance,DECGuideDistance,RADuration,RADirection,DECDuration,DECDirection,XStep,YStep,StarMass,SNR,ErrorCode
INFO: SETTLING STATE CHANGE, Settling started
1,0.532,"Mount",-0.003,-0.014,0.002,0.014,0.000,0.000,0,,0,,,,2509,35.15,0
2,1.031,"Mount",0.031,-0.106,0.063,0.091,0.000,0.000,0,,0,,,,2522,35.23,0
3,1.552,"Mount",0.044,0.028,0.033,-0.040,0.000,0.000,0,,0,,,,2626,35.99,0
4,2.031,"Mount",-0.000,-0.036,0.011,0.034,0.000,0.000,0,,0,,,,2537,35.34,0
5,2.556,"Mount",-0.041,-0.035,-0.028,0.045,0.000,0.000,0,,0,,,,2540,35.37,0
6,3.054,"Mount",0.080,-0.033,0.087,0.006,0.000,0.000,0,,0,,,,2654,36.14,0
INFO: SETTLING STATE CHANGE, Settling complete
7,3.539,"Mount",-0.107,-0.044,-0.087,0.075,0.000,0.000,0,,0,,,,2545,35.39,0
8,4.057,"Mount",-0.045,0.061,-0.062,-0.044,0.000,0.000,0,,0,,,,2449,34.65,0
9,4.528,"Mount",-0.070,-0.116,-0.030,0.132,0.000,0.000,0,,0,,,,2549,35.39,0
10,5.072,"Mount",0.063,0.086,0.032,-0.101,0.000,0.000,0,,0,,,,2484,34.89,0
11,5.549,"Mount",-0.137,-0.072,-0.107,0.111,-0.034,0.000,12,E,0,,,,2627,35.97,0
12,6.050,"Mount",0.113,0.016,0.102,-0.051,0.031,0.000,11,W,0,,,,2512,35.20,0
13,6.561,"Mount",0.328,0.098,0.280,-0.195,0.089,0.000,32,W,0,,,,2446,34.66,0
14,7.117,"Mount",0.321,-0.076,0.329,-0.027,0.107,0.000,38,W,0,,,,2554,35.48,0
15,7.551,"Mount",0.117,-0.022,0.118,-0.015,0.041,0.000,15,W,0,,,,2567,35.44,0
16,8.035,"Mount",0.019,0.018,0.012,-0.022,0.000,0.000,0,,0,,,,2581,35.56,0
17,8.535,"Mount",-0.020,0.102,-0.051,-0.091,0.000,0.000,0,,0,,,,2535,35.25,0
18,9.083,"Mount",-0.008,0.039,-0.020,-0.034,0.000,0.000,0,,0,,,,2624,35.94,0
19,9.535,"Mount",0.056,0.040,0.040,-0.055,0.000,0.000,0,,0,,,,2599,35.70,0
20,10.083,"Mount",0.063,-0.001,0.060,-0.019,0.000,0.000,0,,0,,,,2608,35.82,0
21,10.547,"Mount",-0.105,0.033,-0.110,0.001,-0.035,0.000,12,E,0,,,,2513,35.19,0
22,11.046,"Mount",0.024,0.064,0.003,-0.068,0.000,0.000,0,,0,,,,2531,35.20,0
23,11.555,"Mount",0.197,0.100,0.155,-0.156,0.049,0.000,17,W,0,,,,2653,36.09,0
24,12.104,"Mount",0.212,0.048,0.186,-0.112,0.060,0.000,21,W,0,,,,2591,35.70,0
25,12.541,"Mount",0.056,0.059,0.034,-0.074,0.000,0.000,0,,0,,,,2539,35.29,0
26,13.060,"Mount",0.030,0.037,0.017,-0.044,0.000,0.000,0,,0,,,,2549,35.42,0
27,13.536,"Mount",-0.015,0.075,-0.038,-0.066,0.000,0.000,0,,0,,,,2575,35.55,0
28,14.056,"Mount",0.023,0.065,0.001,-0.069,0.000,0.000,0,,0,,,,2603,35.71,0
29,14.542,"Mount",0.021,0.102,-0.013,-0.104,0.000,-0.042,0,,10,N,,,2502,34.99,0
30,15.045,"Mount",-0.072,0.056,-0.086,-0.031,0.000,0.000,0,,0,,,,2536,35.26,0
31,15.549,"Mount",-0.072,-0.009,-0.065,0.031,0.000,0.000,0,,0,,,,2590,35.62,0

Kevin_A

I can’t see it being a gear problem as the internal gears are randomly positioned internally by nature of their design and never in the same position. That is why PEC will not work. So, to have it happen always just right before a flip seems unlikely. But, that is a weird occurance.

chrjaeger

here is the image again----
https://ibb.co/N9Q6mVy

Another observation is, that the problem occured when shooting images at declinations 44 degrees, 51 degrees and 61 degrees. It did NOT occur for SH2-126 at 40.5 degrees
I live in a place at about 52 N. So, the telescope points at MF very close to zenith. , It is in equitorial mode !!

Kevin_A

chrjaeger personally, i would see what happens with another guide camera… but just a mono mini. Or change all your usb cables as it sounds more like a bad cable or usb port issue while guiding. Strain wave gears are very strong so sky orientation would not affect gearing to that extreme with such a light scope. Mine runs better with a heavier scope. Change the simplest things first before doing anything else!

w7ay

chrjaeger here is the image again----
https://ibb.co/N9Q6mVy

Something is making discrete slippages. Notice specially that the two large slips (three star asterisms) have almost precisely the same magnitude (this makes undertorqued declination dovetail plate less likely, since those slippage will be more random).

What was your camera angle? You did not mention that. That will tell us if the slippage is in the RA or in the declination axis.

It is possible that it is caused by belt slippages. If we knew the camera plate scale (which you also did not provide), we might be able to determine if it is a belt slippage, or a stepper motor slippage (this is why better mounts use servo motors instead of stepper motors).

Return the mount if that is still an option. Healthy mounts do not slip like that, and I don't think it is something you can fix yourself.

Chen

chrjaeger

Hi Chen,

a) focal length is 432mm, ASI2600MM Pro.
b) It is a Declination issue. The telescope moves South. You see that in the logs showing guiding pulses up to the max DEC duration up North.....

Besides that example I also observed a single step slippage but also multiple small steps (up tp 10 or so).

In any case: guiding with that planetary ASI462MC camera works perfect from starting Autorun/Plan up to the point when the slippage occurs. When the situation settles all subsequent images are guided with the new (shifted) image coordinates. And after MF ASIAIR guiding is using the initial coordinates.... perfect guiding ...

chrjaeger

Focal distance ........... 433.55 mm
Pixel size ............... 7.52 um
here is the plate solution: I correct my error: North is to the RIGHT in the image

Field of view ............ 3d 6' 2.4" x 2d 4' 30.2"
Image center ............. RA: 20 30 01.487 Dec: +48 56 52.98 ex: +0.110863 px ey: +0.034614 px
Image bounds:
top-left .............. RA: 20 36 16.291 Dec: +47 24 36.43 ex: -0.071558 px ey: -0.100134 px
top-right ............. RA: 20 36 22.313 Dec: +50 29 53.74 ex: -0.027700 px ey: -0.343302 px
bottom-left ........... RA: 20 24 03.772 Dec: +47 22 43.46 ex: -0.160420 px ey: +0.143249 px
bottom-right .......... RA: 20 23 22.761 Dec: +50 27 54.86 ex: +0.083252 px ey: +0.121162 px

chrjaeger

Hi Kevin,

so far, I can summarize that this DEC issue close to MF occurs if the telescope points high up close to zenith and "higher".

c.f. above: ""Another observation is, that the problem occured when shooting images at declinations 44 degrees, 51 degrees and 61 degrees. It did NOT occur for SH2-126 at 40.5 degrees
I live in a place at about 52 N. So, the telescope points at MF very close to zenith. , It is in equitorial mode !! ""

Now,
I have just discovered in another post (cloudy nights, ZWO AM5 / ASI Air guiding issues) contribution #18 by "The_Last_Starfighter" who is mentioning excatly the same problem. But it was not considered really. Maybe you can contact him, pointing his attention to this post here and the details I have described: general observation and behaviour, PHD2 logs ..

Maybe he finds that interesting...
Best
Chris

Kevin_A

chrjaeger it is quite possible to have a mechanical issue as Chen suggested but not practical to open up the mount unless you are willing to go very far. Belt cog slippage due to a loose grub screw or a really loose or overly tight belt would be easy to see if you remove the 4 bolts holding the black cover on. You can observe the Dec belt and run the mount without this cover plate on. That wouls be the least evasive check. The belt should have 1-2mm of deflection when pressed down with a light pressing of an allen key.

chrjaeger

Hi,

well, I have checked the images (like the one posted earlier) in which I see the lost guiding and, finally, the settled new guiding. All of those were taken with exposure times of 900s.....

To recall: My location is about 53°N and this mount problem occurs when shooting objects with declinations of 44° and higher. Hence the telecope is close to zenith at MF.

and here is the funny thing: For decs 44° and 49° I observe a CONSTANT image shift to the SOUTH of 10.5 arcmin corresponding to a DEC angle change of 0.17 ... 0.18°: reproducible at several nights in which I had to set up mount and telescope including PA etc..
When shooting IC1805 at 61° declination the dec change is about 10% larger, but also constant for different nights.
To me this is not at all guiding problem, it seems to be the mount itself. At 432mm focal length it means an image shift of about 6%.
On top of that, after MF everything seems to work fine as at the start of AUTORUN much earlier on the other pier side including the initial image coordinates are taken again. Guiding is very nice, no problem, but when dithering occurs the telescope axis uses the opportunity to move a bit south again, and gain and again