Understanding the equatorial mount;

[Rachelle]

I've had a browse on past topics on the forum and have no such luck so apologies I've I'm asking something that's already been mentioned.

I've read and reread my instruction booklet that came with my SKYWATCHER EXPLORER 130 TELESCOPE on EQ2 MOUNT but it doesn't actually cover much information (or any at all) on understanding the equatorial mount.

I've managed to align it to the celestial point like it tells me to. Now what? Do I rotate the whole of my telescope without moving the tripod? Or do I use the RA and DEC functions to move it from this point? What do the numbers on the RA and DEC functions mean and how do I use them? How do I track stars and planets as they move across the sky?

I believe all these questions are really basic and maybe a little silly but I really really can't find any explanation in my instruction/set up booklet that came with my scope.

[badgerchap]

You move the scope using the RA and Dec axes, and when motorised it is the RA axis that allows the scope to track the stars. I personally have never used the scales (setting circles I think) and for most people they're unnecessary, but they can be used to find a particular position in the sky. It does take a few nights to get used to an equatorial mount, but eventually it actually makes things a lot easier. The sky rotates around the RA axis, for example, so getting used to this will acclimatise you to the motion of the sky before long.

Posted via Tapatalk on an ageing iPhone so please excuse any erroneous spellings or accidental profanities!

[badgerchap]

Also you can use the slow motion control (flexible doobywobber) on the RA axis to manually track celestial targets, accurately enough for visual work at least.

Posted via Tapatalk on an ageing iPhone so please excuse any erroneous spellings or accidental profanities!

[DaveJFT]

Hi Rachelle

I have had the same scope and mount as you for just over the past year. To be honest, apart from using the RA and Dec scales to aid setting the scope up on the North Celestial Pole, NCP, I've not needed to use them for anything else.

My setup routine is to point the scope at a star - any star - and check the red dot finder alignment, adjusting if necessary. Next align the scope with the RA axis using the setting scales and zero the Declination as best as possible and tighten the RA and Dec knobs and centre the Dec fine adjustment wheel. Then align the red dot finder on Polaris using the Altitude and Azimuth adjustments and lock those. From there I'm ready to go viewing so I slacken of the RA and Dec knobs and manually slew the scope onto my target using the red dot finder, lock them and make my adjustments for RA and Dec using the fine adjustment wheels.

Does this help?

Dave

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[knobby]

Hi

Its pretty difficult to put into words...

but!

the alignment to the North star is just to help the mount be able to track the motion of the stars across the sky. If you look out of the back window (assuming its south) you'll notice the stars etc. Gradually moving from left to right (east to west) in an arc.

The alignment to north star, polaris is just to make the scope able to follow that arc.

When you want to observe, you can loosen the clutches to point to your desired target, theres probably something on you tube that will help.

also look at a meridian flip on you tube, that's how you get from pointing north to south without breaking the scope or mount

Keep at it and good luck

[Helen]

Welcome to Sgl :-)

There are some great videos on theis site http://www.eyesonthesky.com/Videos/TelescopeBasics.aspx that might help you

Have some practice in day light and hopefully it'll start to become more natural

Helen

[E621Keith]

These video tutorials may help

Edit: be careful with the first video. I don't recommend you use the technique he used if your EQ mount is larger than a EQ2. Ideally, polar alignment should be carried out when the mount is unloaded, the only exception is when you need to drift align to fine tune the polar alignment.

[DaveJFT]

Oh yes, this seems obvious now but initially, a year ago, I thought I was doing some sort of bodge... as you're slewing your scope to your target you'll almost certainly need to rotate the scope within the tube rings to get the focuser into a convenient orientation to see down it.

I found (and still find) that this can cause the scope to slide along its axis and upset the balance you've fought so hard to achieve. I use some making tape as a marker to slide the tube back to as it's light coloured against the dark tube of my scope.

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[DaveJFT]

"masking tape" ... sorry, stoopid phone!

...stoopid forum for not letting me edit my posts too.

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[NotSoSuperNova]

I just went out there like a fool and started playing around until my EQ mount made sense. It took a few nights but I do feel I understand the thing now, it does everything for a reason (though some things are more useful than others) Being an engineer I had a great time fiddling but I can imagine people getting frustrated at not being told 'A' plugs in to 'B' and does 'X'. Doesn't Astrobaby do a guide that pretty much does that?

[NotSoSuperNova]

You'll almost certainly need to rotate the scope within the tube rings to get the focuser into a convenient orientation to see down it.

You know Dave, if you set you EP to point directly up when looking at Polaris (so you'll probably need a chair to check) you'll almost entirely get rid of that issue. Someone told me that the other day and when I checked it out, I was whizzing my scope round for 3 whole minutes trying to find something that needed the tube rolling for.

[DaveJFT]

BTW - and sorry to hijack the thread - does anyone know what the metal disk with the tang sticking off it and held on by a screw does on the right hand side of the mount next to the RA worm drive?

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[DaveJFT]

You know Dave, if you set you EP to point directly up when looking at Polaris (so you'll probably need a chair to check) you'll almost entirely get rid of that issue. Someone told me that the other day and when I checked it out, I was whizzing my scope round for 3 whole minutes trying to find something that needed the tube rolling for.

Oooh, thanks NotSoSuperNova. I'll give that a try.

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[NotSoSuperNova]

It'll Blow your mind

[Twiggles]

BTW - and sorry to hijack the thread - does anyone know what the metal disk with the tang sticking off it and held on by a screw does on the right hand side of the mount next to the RA worm drive?

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I believe you are referring to the RA motor cam. By using the little 'tang' or lever you can move it up and it will disengage the motor from the worm gear when you want to move the mount or do a little manual fine tuning.

[DaveJFT]

Oh ok, thanks. I guess it's for a different RA motor to the basic £30 one that I have which mounts directly to the other end of the RA worm drivebar in place of the flexible control cable.

[Thread hijack over]

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[faulksy]

this how i leared the use of a gem mount

http://www.rothervalleyoptics.co.uk/beginners-guide-to-equatorial-mounted-telescopes-dvd-video_d1273.html

very good

[Steve Ward]

Try Rogers new tutorial ......http://stargazerslounge.com/topic/182904-setting-up-an-equatorial-mount/

[triton1]

I to have put some tape on the ota.Not tried alighning ep with polaris in upright position but i,ll give it o go

thx jonn

[Tinker1947]

On a Reflector you can place piece of plastic, in my case a 1 Metre ruler cut down to size, get a large Jubilee clip off E-bay , place these above the top ring and once balanced you can loosen the tube rings and spin the tube to get the EP in a better position for viewing,,,if your do AP then your stuck with the tube at what ever angle it ends up at, as spinning upsets the fine balance that AP requires...

[Rachelle]

Thanks for all your replies and suggestions. I especially loved Rogers tutorial and David Fullers videos and website...that guys a genius! Think I'll have a play with the mount tomorrow in the garden. Practice makes perfect, right?!

[DaveJFT]

Hi Rachelle

Just one more thing, you asked about how to use the RA and Declination setting circles - just because I don't use them doesn't mean I shouldn't help others to use them if I can, so...

When I received my scope it came with a booklet on how to use the EQ2 mount. Here is a link to a copy on the web:

https://www.google.co.uk/url?sa=t&source=web&cd=1&ved=0CDIQFjAA&url=http%3A%2F%2Fwww.ursa.fi%2Ffileadmin%2Fursa2010%2Fkuvat%2Fkirjakauppa%2FGENERAL_EQ1and2.pdf&ei=e7pjUY6WIajb0QXMhYGwBg&usg=AFQjCNHpv1JTxAFvJIA5g8YnYb3etRi9aA&sig2=nhSQEld5C53_Ib6azs7KWg (I hope the link works - no reason why it should if I'm not allowed to even edit my own posts ...winge ...winge)

Page 15 describes how to use the RA and Dec setting circles and having read it now I might have a go at using them to help me find some of the messier objects I'm struggling with.

Anyhow, good luck.

Dave

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[Bizibilder]

In reality the setting circles of modern scopes are next to useless - they are far too small and cannot be locked in position properly. It is far easier, when trying to find an object, to locate a bright, nearby, star and use the wide field of view of the finder to "star hop" to your object of choice. It is tricky to do to start with but, with practice. becomes quite easy (bit like riding a bike!).

[Rachelle]

In reality the setting circles of modern scopes are next to useless - they are far too small and cannot be locked in position properly. It is far easier, when trying to find an object, to locate a bright, nearby, star and use the wide field of view of the finder to "star hop" to your object of choice. It is tricky to do to start with but, with practice. becomes quite easy (bit like riding a bike!).

Thanks! That's kinda what I've been doing all along but wondered if using them would make it any easier. From what I've read on this thread, they're pretty useless apart from making the tripod look a bit more technical and chunky.

[Rachelle]

When I received my scope it came with a booklet on how to use the EQ2 mount. Here is a link to a copy on the web:

https://www.google.c...5C53_Ib6azs7KWg (I hope the link works - no reason why it should if I'm not allowed to even edit my own posts ...winge ...winge)

The link worked fine - thanks Dave! I'll make some spare time later to read through it. Much appreciated!