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setting circle troubles.


tuckstar

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So last night I popped to ww with the Dob. Bit windy but was ok round the back of the hut on the car park.

Set up and aligned to polaris. Now if I go from there the setting circle was bang on star hopping through to vega, through pegasus and andromeda so from 0' backwards to 120' so 3/4 of the way round. Then from Andromeda to triangulum and Aries it was out by 6 or 7 degrees. Like wise if I go from polaris to capella it was again around 5 degrees out. Both times straight back to polaris and it's was bob on.

Can't work out what's going on. Setting circle isn't missing any numbers or anything like that and I made double sure the circle hadn't slipped. Slept on it and still puzzled. If 0' is right, 270' is right and 180' is right

how could 90' be out!!

Even managed to get Uranus using the setting circle and wixey no problem. Just seems to be that first 100' or so.

I have been using sky safari 4 for Co ordinates.

Any ideas people?

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Is your base level Andy?


 


I know that if mine isn't it can make it not accurate enough. Never been 6° out though.


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As level as it could be on ww car park. It has got shed leveling feet. Think I'll have to try again in the garden and make sure everything is as it should be and then work around again and pin point where it's out.

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Is there a magnet on your phone case? I have had this problem with my coordinates being out, and I found that the magnet on the case interfered with the app.


 


Try getting the coordinates from Stellarium on a lappy or tablet, and compare it to those on your phone, my lappy was bob on every time.


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I'll try that. It's a built in case and flip front so no obvious magnet but I can change case and try again. Looks like I might get an hour tomorrow to try it at home with the computer at hand.

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So, changed case on phone, checked sky safari against stellarium on computer. Both reading same. Quick go, and error seems to be down to about 1 degree. Think this is only due to slop around setting circle and lazy susan bearing. Hopefully the small clamps I have coming will reduce this further still.

So Martyn it seems you have triumphed again.

I am surprised that it affects it as it is a very small magnet. Not like the big round ones you get on after market cases. So, If any one has a Samsung with the flip window case be aware.

Thanks again.

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I think it's the magnet that activates the phone when you open the case, it does on mine. I thought it might be light activated, but it still works in the pitch black.


After taking my case off, I got better accuracy.


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It must have been that. I knew the setting circle couldn't be that far out without being egg shaped.Just need to play with the slide guides a bit more now seems to not quite catch but more pressure required to rotate in some spots than others, and some spots a bit loose.

Still love how enthusiastic my 6 year old is, in fact she persuaded me to get the scope out, and it's much better now she doesn't have to wait as long for daddy to find things for her to look at especially now I've got the 250 she can actually see objects, but it's still the moon that provides the "wow", she wasn't that impressed with Neptune. :-)

Edited by tuckstar
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Clamps on. Only home made jobbers and not taking any strain, but one on each side just takes the slop out of the setting circle and now it's quite accurate.

Now for the alt bearings.....

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