Diy Scope upgrade for cheapskate and newb..

[zultan]

To dip a toe into the Astronomical waters I purchased a Celestron Astromaster 130mq over a year ago. Sadly, I've still not managed to point it successfully at anything smaller than the moon. I also now agree with all the reviews that said the finder and mount are below par.

Then I noticed the NexStar 130SLT, which appears to be my scope with a GoTo style mount: http://www.celestron.com/browse-shop/astronomy/telescopes/nexstar-130slt-computerized-telescope

I've also noticed that I can obtain the computerised SLT clever part of the mount from eBay: http://www.ebay.com.au/itm/Celestron-NexStar-SLT-GoTo-One-Arm-Altazimuth-AZ-Mount-Missing-Faceplate-/271413280073?pt=LH_DefaultDomain_0&hash=item3f317dfd49

Can anyone tell me if it it would likely be possible to mount my scope on this motorised thingy, utilising my existing tripod?

thanks :)

[Poita]

I think you would also need the hand controller.

[julianh72]

The short answer is that no, I don't think it will fit. The SLT mount goes into a special "cup" on the tripod, which is unique to the Celestron SLT-style mounts - see attached photos. Without the "cup" and hand controller, the mount won't be worth anything to you.

[julianh72]

What is the main problem with pointing the telescope? While the mount supplied isn't the most heavy-dury mount around, it should handle that telescope without too much trouble, for visual use at least. Do you need some assistance with how to align and use a manual (non-GoTo) EQ mount?

[glend]

I have a Celestron Astromaster 130 which was a gift, and I agree that the standard CG3 manual mount is not very good, but it can be used if you know how to align it and find objects by hopping etc, but there are alternatives. I run Astromaster 130 on an iOptron Smartstar G Goto mount and it works fine. Normally the iOptron Smartstar is used for 90mm refractors but it can hande the weight of the Astromaster 130 provided you do a couple of standard mods for the iOptron Smartstar cube. The mods are:

Replace the standard size teflon clutch washer with a slightly larger one, which will prevent slippage, and
Secondly, brace the altitude gear carrier with a short piece of pencil on each side against the cast medal body.

I have run a AR102 short fl refractor on the mount without slippage. I regularly use the Astromaster as a solar scope - with appropriate filter of course. The iOptron Smartstar tracks the object very well and gets the GPS co-ordinates on startup. It is also the cheapest goto mount you can buy - they usually sell around $500 new but you can get them for less second hand. People tend to sell them because they don't know how to md them to handle more weight. Just do a Google search for iOptron Smartstar reviews and mods - its all there.

I have also had it on my Vixen Porta II Alt-Az mount, and it works fine on that manual mount - which also has train and track motors available for it.

In the end, if your using a manual or non-goto mount you need to know something about finding objects in the sky, using planetarium apps, charts, or key bright indictors

[zultan]

Thanks for the info everyone. Yes, the main issue is that I'm having real trouble navigation the night sky, even at a 'spotter' magnififcation I can't identify something obvious like the southern cross is beyond me - even through a set of binos.

(that said even the GT mount can be found cheapily, with the hand-controller included. http://www.ebay.com/itm/Celestron-Telescope-One-Arm-Motorized-GT-Mount-With-NexStar-Hand-Control-Bundle-/281274860276 )

[julianh72]

I think the GT mount and the SLT mount are basically pretty much the same as each other, except the GT has an external battery pack with a cable to the mount, and the battery pack is built into the hub of the SLT mount. The SLT will also take a normal 12 volt DC input, which is highly recommended, as it will chew through a set of 8 x AA batteries pretty quickly. (Contrary to what you may have read elsewhere, you CAN run the SLT mount on NiMH rechargeables, and a set of fully charged batteries will get you through an evening between charges, but it's a good idea to carry a spare set of 8 batteries if you don't have a DC power supply, because the mount can't be used manually - it has to be powered.)

I took a closer look at the bottom of my SLT mount - you MIGHT be able to fit it onto a standard tripod. It is secured in the special "cup" on the Celestron tripod using a single central bolt, and this in turn is held in an adapter plate on the underside of the mount which is held by two screws. (See attached photo.) You might be able to adapt this fitting on the bottom of the mount onto the top of another tripod.

[omegacrux]

Hi Mike
Have you tried some smartphone apps ?
They can be a big help . Stellarium , skyeye and Google sky maps
Skyeye once trained can be used as a push-to , meaning it helps you find the object with arrows

David

[brian nordstrom]

:question: The southern cross (Crux) is the smallest constilation in the sky at 104 sq degrees and its way to big even for binoculars so don't expect to be able to navigate easily, there are just to many stars .
Get a good star atlas and planesphere .

Like most newbys like you , you expect it to be easy , but sorry to say ,,, its not and it takes time to learn the sky , just start at Crux and from there the 2 pointer's ( a and b Centatui ) and so on learning the bright stars visable for this time of year , but in 3-4 months it would have changed a bit but don't worry , learn some more and it just takes time .

Astronomy is the hobby for a lifetime so take your time learning using just your naked eye , the stars aint going anywhere .

Brian.

[julianh72]

For a complete beginner, if you have a smartphone or tablet, Google Sky Map is a great starting point.

It only shows the brightest objects (basically, naked eye objects only, plus the most obvious targets for small telescopes and binoculars), and it will align its view with where you point your phone, so it will very quickly help you identify what you are looking at, and will also point you towards a target that you are seeking out. A few nights with Google Sky Map will help you learn the names of the brighter objects and constellations in the night sky.

One of the more powerful planetarium apps (e.g. SkySafari 4, Stellarium, SkEye, etc) will have a MUCH bigger database than Google Sky Map, a LOT more information on the objects in the database, and will allow you to zoom in to MUCH higher magnification. However, the sheer number of objects they can display can make it hard for a beginner to correlate the view in the app with what they see in the sky. If you live in a light-polluted city, you may only see a few dozen stars with the naked eye when the Moon is out, whereas the app will show hundreds or thousands, and understanding which are the ones you can actually see can be tricky.

For example, we all "know" the Southern Cross has 5 main stars (although there are actually many more than just 5), but the fifth star may be hard to spot on a bright night, if you're not sure which way up the Cross is pointing.

With a planetarium app such as SkySafari, you can adjust the magnitude of stars which are displayed. It is tempting to set this to a large number (remember, higher magnitude number = fainter stars; that in itself is confusing for beginners!), so that you see LOTS of stars in the app, but this can be confusing, as it displays lots of stars that you can't actually see with the naked eye or binoculars, so it can be hard to correlate the app view with the naked eye view.

Try setting the magnitude limit to about 3.5 to 4 (6 is roughly the naked eye limit for a dark sky), and the view that you see in the app should be a reasonable approximation for what you can actually see from a typical urban site.

Once you can identify some bright naked eye objects in the night sky, try pointing your telescope to them. Use this to make sure your finder is properly aligned, and get some understanding of how wide / narrow the field of view is with your various eye-pieces.

The Moon is probably the best place to start - it is pretty easy to find(!), and remembering that the Full Moon is about 1/2 degree across, when you find an eyepiece for which the Moon fills the view, you know that eyepiece gives you a field of view of 1/2 degree. With that eyepiece, you will need to point the telescope to better than +/- 1/4 degree accuracy in order to get your target into the field of view. There aren't many bright stars that are close enough together to be both visible in 1 degree or 1/2 degree field of view, so when you are pointing your telescope, you are typically going to be pointing it at a single bright naked-eye star - but through the eyepiece, you will often see dozens of stars that are not visible to the naked eye - but the single bright star will be obvious when it is in view.

Once you are more familiar with the night sky, you can crank up the magnitude limit in your planetarium app, and start to use the app for finding fainter targets with your telescope.

Hope this helps!

[Pinwheel]

I agree with Brian here, I started with a basic Kmart telescope 35 years ago, then in time moved to bigger & better toys including EQ mounts. The point is over time you learn your way around the sky. Having this knowledge self learned burned into your brain is great as you know in advance where & when to point your scope at the targets you want to see. People using goto & skymapping devices are really missing the point!

[zultan]

Thanks again. Well, I did manage to find the Jewel Box with a pair of binos last night, so there is hope for me yet ;)