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Old 14-09-2010, 04:12 PM
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Geoff45 (Geoff)
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Wierd guiding with Losmandy GM8

Has anyone ever seen this guiding behaviour on a Losmandy mount and. more importantly, does anyone know what to do about it?
This started on Saturday night. The mount guides fine for a minute or two, then suddenly the dec motor just seems to keep going--always in the same direction, as shown on the attached graph.

Summary:
Mount: GM8
Software: MaximDL
Guide camera: Starlight Xpress Lodestar
Guide interval: 2 sec
Main camera: QSI 540wsg

I tried guiding with the Lodestar issuing guiding commands ("Guider relays" in Maxim) and then the main camera giving the guiding commands ("Main relays") . The behaviour in both cases was the same, so that seems to rule out both cameras.
The system was working fine on Wednesday.
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Old 14-09-2010, 04:21 PM
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Octane (Humayun)
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Balance? Dodgy cables?

H
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Old 14-09-2010, 04:23 PM
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Balance not a problem. Dodgy cables--maybe, but how do you check?
Geoff
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Old 14-09-2010, 04:28 PM
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Swap the cables around. ; )

H
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Old 14-09-2010, 05:59 PM
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When the cable the st4 cable is damaged, it is usually the dec - as it is on the end of the plug. I have done it a few times now, when it catches during a slew.

Buy the termination tool and reterminate yourself, it is not hard to do.

Brett
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Old 15-09-2010, 08:41 AM
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I don't think it can be the autoguider cable, because I used one cable for the lodestar and then a different cable for the QSI and in both cases the behaviour was the same.
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Old 15-09-2010, 10:21 AM
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What about the actual cables for the motors? That's what I was referring to. : )

See if you can reverse them and if the problem then occurs on the RA motor, well...

H
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Old 15-09-2010, 01:39 PM
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Quote:
Originally Posted by Octane View Post
What about the actual cables for the motors? That's what I was referring to. : )

See if you can reverse them and if the problem then occurs on the RA motor, well...

H
Yes i understood what you meant. The comment about the AG cable was directed at Brett. I'm about to go downstairs and try all the possibilities out in the daylight. I suspect that the Dec motor, for whatever reason has a problem responding to the AG commands. It comes down to 3 things I think
1. Faulty motor
2. Faulty cable from Gemini box to motor
3 Problem with the Gemini box.

I'm pretty sure I can eliminate cameras and autoguiding cables.
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