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Well the clouds went away!

Tomight I tried out a whole new bunch of stuff and thought I would have a go at M101.

One of the key things I wanted to establish was how long I could make my exposures (using my new timer trigger thingy).

So I pointed at M101 and set up for 2 minuite exposures.

I fired of a test shot and was proper pleased with no noticable drift (polar alignment was probably the best I've done).

So I dial in 30 shots all at 2 mins and the camera goes to work.

When I review them something odd has happened. The first three exposures are bang on, the fourth sees the beginning of a wiggly trail and from there on in the trails just become epic - proper long star trails (all lines, no hint of star!)

So I'm wondering what might have happened.

Setup is NEQ6 being run with eqmod from a laptop. The "event" seemed to happen at 23:30 ish.

I'm wondering if the powertank maybe went flat or the cat leapt onto the keybaord (would not be the first time). Or wether something more technical was going on (M101 was pretty straight above me and the scope was vertical).

Any ideas would be of interest as I can't work out what could have caused a catastrphic change.



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I must admit I thought something might have slipped - but all was balanced when I broke down and cables were pretty clear. I've not experienced a flip before and have no idea what the effects would be - but this was one thought I had. The other possibility I'm think of is if the game pad rolled onto one of the joysticks (interestingly the scope would not park when done either).

I should say that Chilli the Cat is not off the hook either!

Despite this puzzling setback, I have to say it was a very useful session as it's the first time I've eqmod in anger with the game pad. I've also found out that my sky will allow 2 min exposures easuly and I may be able to double that without glow becoming an issue. (the only limitation being tracking). So I can now consider phase 2 and have a play with guiding!

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Or is it possible that the scope itself snagged on the tripod?

I had that once. Knew I was getting close but it wasn't until I checked the last sub that I saw that it had.

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I'm not even an imager, but I've seen on other threads that you can have a scope too well balanced. Apparently you are best to have it slightly biased one way or the other so the drive is always working in the same direction. If the motor flips from pushing on the gears to slowly giving ground to gravity you can get a bit of wobble. Alternatively sell the EQ6 and get a Dob!

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Tripod snag Hmmm.....there's a thought, it was close to the leg, possibility I hadn't conidered.

James - I'd never heard or even considered that - I follow the logic though.

I think I just need another clear night to run some more work.....might be a long wait!

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I got that when I was using a power cable from mains that wasn't providing full power at all times and so the tracking went off. I got those super long trails as you said, after a couple of good subs. I don't know about your mount but mine needs a good steady power supply or it goes whacky. Since changing cables and also using my 3-in-1 car starter power pack (which I charge 1/mth) I've not had any trouble!


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I've had the same thing 2 nights running while imaging M82, at around the same time (midnight ish)....The last time this happened I'd not locked off the collimation screws for the primary, so that was the cause. This time, everything is tight and I can't find any evidence of a snagged cable, so it's a mystery ;)

This is with a well balanced AP1200 carrying a 10 inch RC, so nowhere near capacity, with a target a fair way past the meridian.

I'm sure it'll turn out to be something simple (I had a seagull land on a scope once....fortunately, it didn't leave anything behind :D)

Sometimes, with stuff as complex as AP gear, things happen :)


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