Can someone spot my problem please

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Tony Sturchio

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Sep 11, 2021, 8:55:04 AMSep 11
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https://openphdguiding.org/logs/dl/PHD2_logs_CJDw.zip

Hi,
I cant seem to figure out what I am doing wrong, again.
Thank you,
Tony Sturchio

wave...@talktalk.net

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Sep 11, 2021, 11:07:11 AMSep 11
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Hi Tony, I suspect you'd learn more by running the Guiding Assistant after doing a successful Calibration (no alert messages). I'd say you have some backlash in the Dec drive (very common) which might be affecting Calibration, so ensure you eliminate backlash before starting. Do that by pushing the guide star North using the handset guide speed button or via the Manual Guide option on the Tools tab. Set the pulse width to around 5000ms for this. Once the star has obviously shifted North, start a Calibration. When that's done, guiding starts automatically, so invoke the Guiding Assistant and let it run for a few worm cycles. This will will enable you to establish the mount's unguided performance.
There's more info here:  Baseling Guiding
Once you've done that and uploaded the logs I'm sure the PHD2 gurus will provide a much deeper insight.
Cheers,
- Jack

sturch

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Sep 11, 2021, 11:24:04 AMSep 11
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Hi Jack,
Followed that procedure many times.
I am thinking something mechanical is going on.
Been having this same outcome for almost a year.
Thank you for your reply.
Tony



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bw_msgboard

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Sep 11, 2021, 11:26:35 AMSep 11
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Could you give us a little context on this?  What problems are you seeing and what sort of equipment configuration are you using?  Is this a new problem or a recurring one?
 
Bruce


From: open-phd...@googlegroups.com [mailto:open-phd...@googlegroups.com] On Behalf Of Tony Sturchio
Sent: Saturday, September 11, 2021 5:55 AM
To: Open PHD Guiding
Subject: [open-phd-guiding] Can someone spot my problem please

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sturch

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Sep 11, 2021, 11:38:31 AMSep 11
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Hi Bruce.
Recurring problem.
Losmandy g811.
I did PA in Sharpcap.
Did calibration at celestial equator with bump north prior.
Did guiding assistant and apply at finish.
My guiding has been getting worse and worse for a year now.
Thank you,
Tony Sturchio



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bw_msgboard

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Sep 11, 2021, 3:49:40 PMSep 11
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Hi Tony.  I think there's something substantially wrong with the Dec axis at this point.  It could be that something has come loose or maybe the mesh is way off, but it isn't really workable in its current state.  The calibrations you got were nearly useless because the Dec measurement was poor.  At the location you were pointing, the RA and Dec guide rates should have been nearly the same - but your last RA and Dec guide rates, calculated by PHD2, were 7.4 arc-sec/sec and 2.4 arc-sec/sec. Here are the gory details of how the guide star moved in declination during your last calibration.  The only thing to look at is the right-most column which shows the guide star sensor location for Dec:
 
orth,0,0.000,0.000,296.323,919.423,0.000
North,1,1.599,-0.177,294.724,919.600,1.609
North,2,5.237,0.877,291.086,918.546,5.310
North,3,5.835,1.260,290.489,918.163,5.969
North,4,8.111,1.991,288.212,917.432,8.351
North,5,8.214,2.337,288.109,917.086,8.540
North,6,8.540,1.702,287.783,917.721,8.708
North,7,8.418,1.764,287.905,917.659,8.601
North,8,8.478,1.849,287.846,917.573,8.677
North,9,9.065,1.551,287.259,917.872,9.196
North,10,9.071,1.006,287.252,918.417,9.127
North,11,9.082,0.884,287.242,918.539,9.125
North,12,9.496,0.659,286.827,918.764,9.519
North,13,9.200,0.649,287.123,918.774,9.223
North,14,9.299,1.172,287.024,918.250,9.373
North,15,9.089,1.267,287.234,918.155,9.177
North,16,9.451,1.218,286.872,918.205,9.529
North,17,9.491,1.357,286.833,918.066,9.587
North,18,8.145,1.119,288.178,918.304,8.222
North,19,7.538,1.093,288.785,918.330,7.617
North,20,6.455,0.660,289.868,918.763,6.489
North,21,5.162,0.590,291.161,918.833,5.196
North,22,3.747,0.306,292.576,919.116,3.760
North,23,3.122,0.229,293.201,919.193,3.130
North,24,0.854,-0.505,295.469,919.927,0.992
North,25,-0.687,-0.979,297.010,920.401,1.196
North,26,-2.755,-1.727,299.078,921.150,3.251
North,27,-4.001,-1.881,300.324,921.303,4.421
North,28,-6.537,-2.622,302.860,922.045,7.043
North,29,-7.596,-2.751,303.919,922.174,8.079
North,30,-9.592,-4.442,305.915,923.865,10.571
North,31,-10.685,-4.675,307.008,924.098,11.663
North,32,-12.562,-5.676,308.885,925.099,13.785
North,33,-13.310,-6.112,309.633,925.535,14.646
North,34,-15.576,-7.272,311.899,926.695,17.190
North,35,-16.729,-7.812,313.052,927.235,18.463
North,36,-18.852,-9.252,315.175,928.674,21.000
North,37,-20.158,-9.768,316.482,929.191,22.400
North,38,-22.110,-10.766,318.433,930.189,24.591
North,39,-23.747,-11.198,320.070,930.621,26.255
 
It should have increased at a consistent rate.  But you can see it started out with big moves, then flattened off to little or no movement, then reversed direction twice before finishing. This needs to be fixed, for sure.
 
It also looks like you might have set a backlash compensation value in the mount driver or controller - that needs to be cleared in order for guiding to work.
 
I suggest you take this up with Losmandy support.  Brian Valente works there and he is completely conversant in how PHD2 works.
 
Good luck,
Bruce


From: open-phd...@googlegroups.com [mailto:open-phd...@googlegroups.com] On Behalf Of sturch
Sent: Saturday, September 11, 2021 8:38 AM

sturch

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Sep 11, 2021, 4:41:15 PMSep 11
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sturch

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Sep 13, 2021, 2:10:23 PMSep 13
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Hi Brian,
I only adjusted the mesh on the worm according to the video.
I know it is fine.
What is weird is how much backlash there is between the 2 aluminum gears underneath the cover.
That seems excessive to me, but that might be from me working in machining background and knowing backlash.
Otherwise, i dont think anything else has changed.
Thanks,
Tony



Sent via the Samsung Galaxy S7 active, an AT&T 4G LTE smartphone


-------- Original message --------
From: Losmandy Support <sup...@losmandy.freshdesk.com>
Date: 9/13/21 12:41 PM (GMT-05:00)
Subject: Re: FW: RE: [open-phd-guiding] Can someone spot my problem please

Hi Tony,

I'll take a look at ​your logs. ​What has changed since we last spoke? ​have you changed any settings or done anything regarding the mount hardware?
Brian


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