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Eq5 leveling bubble not level


SteveBz

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The mounts accuracy doesn't need to be good. You can be a long way off level, it's the polar alignment that is really important.

I wouldn't bother messing with it. It wont improve your viewing.

cheers

gaj

 

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Not sure if your Celestron mount is the same as my EQ5, but on mine there's a plastic plug on the under side where the bubble level sits which I think can be removed.  It might be possible to shim or otherwise alter the bubble level's position and get  things back on an even keel.  

Edited by almcl
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2 hours ago, almcl said:

Not sure if your Celestron mount is the same as my EQ5, but on mine there's a plastic plug on the under side where the bubble level sits which I think can be removed.  It might be possible to shim or otherwise alter the bubble level's position and get  things back on an even keel.  

Just pulled it apart. This is what it looks like:

tmp_31323-20160915_1548451262759466.jpg

Maybe I can just pull it out and refit it.  It's no use as it is.

Steve.

 

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6 minutes ago, wuthton said:

Level by eye is more than accurate enough, even if you're only wearing one shoe. 

Nice post.  I still have an unhealthy attachment to my cg5.  I've nursed it back from the edge of the wheelie bin (see my other posts) and I don't want it to walk with a limp if it doesn't need to.

It's just me being obstinate not that there is any real need to fix this.

Thanks for your post.

Steve.

P's I'm gonna go and pull off the rubber bit and see what I find.  Report back later.

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1 hour ago, SteveBz said:

PS I'm gonna go and pull off the rubber bit and see what I find.  Report back later.

Ok. This is what I found, a nice rubber bung, an old bubble level and some bits of expanded polystyrene :

tmp_14240-20160915_171712-438632362.jpg

I got a small tap washer, drilled it and used it to replace the expanded polystyrene like this:

tmp_22304-20160915_172046-438632362.jpg

tmp_22304-20160915_172113596113781.jpg

It's better than before but not perfect.

I'll try again later, but the bottom line is that I think it's fixable.  If I improve it sny more I'll say so.

Thanks all.

Regards

Steve.

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I wouldn't worry too much about it Steve. These are mass produced mounts and cast parts are never as accurate as machined ones. You could get the bubble to fit perfectly and find the bubble holder in the mount is off. It's like the setting circles on EQ mounts. They put them on the mount but the scales on them are so small they are practically useless. Similar with the bubble. They put them on the mount and while to some degree they offer a reference they are so small they can't be considered all that accurate anyway. I think there is actually a proper bubble level you can buy for accurate levelling that attaches under the mount and hangs out the side. I thought FLO did them but can't find them on their site ??

As others have said though polar alignment is more important but again polar scopes in budget mounts are not as accurate as people think and imagers only use them to get rough PA then drift align.

Edited by spaceboy
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  • 2 weeks later...

It won't matter if the mount isn't level. I was going to say "roughly level" will be good enough, but that isn't even true, you could have the one leg 10cm fully longer or shorter than the others and have the mount cockeyed, but as long as your polar alignment is good (and that will is achieved independently of how level or not your mount is) you'll be tracking fine. And if you are using GOTO then the star alignment process compensates for any wonkyness.

So I would save yourself the hassle of trying to get this perfect. You'd be far better stripping the mount and cleaning the innards and greasing them nicely.

James

 

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4 hours ago, jambouk said:

It won't matter if the mount isn't level. I was going to say "roughly level" will be good enough, but that isn't even true, you could have the one leg 10cm fully longer or shorter than the others and have the mount cockeyed, but as long as your polar alignment is good (and that will is achieved independently of how level or not your mount is) you'll be tracking fine. And if you are using GOTO then the star alignment process compensates for any wonkyness.

So I would save yourself the hassle of trying to get this perfect. You'd be far better stripping the mount and cleaning the innards and greasing them nicely.

James

 

So should I fill in the hole? Or expand it and use it for something else, like a socket for a dew heater?  I'm distracted by the fact that it is there and not working.

I've already stripped the mount, wetndry'd the worm gear and regreased it.  It's taken several weeks, and because that now works so beautifully I can't bear other bits not to work equally well.

Any suggestions for it's new use gratefully received. :smiley:

Steve.

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  • 3 years later...

it is true that with the standard polar alignment the tripod platform needs only to be roughly level. However, if the view of Polaris is obstructed and one wants to use the reverse polar alignment, then the platform has to be level.  For the reverse polar alignment one goes through the normal set up steps of the Go To manual as if the mount was already polar aligned.  Then one let the mount slew to a known star, which will generally not be in the center of the field.  Now one uses only the AZI  and ALT adjustment screws to bring the star into the center.  Apart from the level platform the telescope axis must be exactly parallel the main rotational axis (RA axis).  This can be conveniently done at day time by adjusting the DEC axis so that the telescope points at the same object as the built in polar scope (negligible cone error assumed).

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