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Skywatcher 150P on SW Star Discovery mount ?


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Just now, Anthony1979 said:

Is the single motor be all i need or would i be better just getting the duel one

That's a good question.  Not for visual, but I think that imagers prefer both.  You will need to research that online.

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6 hours ago, Alan64 said:

That's a good question.  Not for visual, but I think that imagers prefer both.  You will need to research that online.

My EQ5 has RA drive only, + manual Dec drive.  I originally intended this for visual use only.  I tried it a few times for planetary imaging and it proved to be usable for that.  It is  orders of magnitude more stable than the SLT mount and tripod and even though the Discovery GoTo mount is a size bigger, the same remarks will apply.

A disadvantage of having RA drive only is that it is awkward not having both slow motions in the same place and working with the same feel.

Ideally I would prefer GoTo on this mount but I am baulking at scrapping the existing drive and 6v power kit and paying 300 pounds for a GoTo kit.

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This is the only video I could find, for the manual version... https://www.youtube.com/watch?v=0WqsmXpTqYk&t=375s

This video may be helpful as well... https://www.youtube.com/watch?v=yHGmzpsChcg&t=525s

How to use any equatorial... https://www.youtube.com/watch?v=v5tfQ7v3GL0

There are only two major parts: the tripod, and the mount-head; then all of the other, smaller bits and bobs to complete it.

Edited by Alan64
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Some thoughts upon your new acquisition...

The EQ-5 is the sweet-spot among equatorial mounts; not too large, not too small, just right.  

You can attach all sorts and sizes of telescopes, large and small, for most any purpose, and upon just one, single mount; no need for a collection of mounts, save perhaps an alt-azimuth, for that grab-and-go ease when travelling or other.

A manual EQ-5 has a distinct advantage over the others.  If the computer or motor(s) fail on an HEQ-5 or EQ-6, they would be dead in the water until repaired, and parts for those are costly; a king's ransom even.

With the manual EQ-5 fitted with a motor or a go-to system, you'd be able to strip them off, as though they were clothing, and use the telescope manually with the slow-motion controls.

Your 150P won't know how to act when mounted; held fast and rigidly, and ready to sail the celestial seas.

Know your mount, and once you get to know it well enough, you can think about making it the very best it can be; just a little something to tuck into the back of the mind for the future...

https://www.youtube.com/watch?v=8tZ58AVVyuQ&t=1166s

That mount is the same as yours, but with the go-to kit fitted.  The metal construction of the mount is the same.

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1 hour ago, Anthony1979 said:

Last question.... Should this not level out to zero

 

Theoretically yes, but in practice no.  It will also be irrelevant to you because your latitude will be about 53 degrees, that is where the pointer will be when you adjust the mount to the correct latitude.

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1 hour ago, Anthony1979 said:

So i dont really need to worry about it then

You do need to throw the mount-head back a bit until the pointer(outlined in red) points to 53° N...

Anthony1979.JPG.e4f4a8315428d7c128bcd414985e0c57.JPG Anthony1979b.JPG.fb18e3c04eccc72c3f00dc8dec9566b6.JPG

53° is in between the first and second white indicator-lines after the 50°-mark.  Once you set it to your correct latitude, you'll should never have to touch it again; unless you move or travel considerably north or south from where you are now.

When setting the latitude, you are pre-aiming it at Polaris, the North Star.  Once you take the mount outside, Polaris will be in the northern part of the sky 53° above the horizon; above the tree-line, where the trunks of the trees meet the ground.

You must level the mount, with a bubble-level, and easy enough to do, then rotate the mount-head side-to-side, perhaps the tripod as well, until the mount-head's RA-axis points to Polaris....

axes3.jpg.e918d13f09809827b5a31e7b42a33f5e.jpg

When imaging, you'll probably need a polar-alignment scope, which screws into the back of the RA-axis...

https://www.firstlightoptics.com/sky-watcher-mount-accessories/skywatcher-polarscope-for-eq3-2-eq5.html

This is what you'll see through the scope...

190999289_polarscope2.jpg.50a6671b8f0dbc268904b0efc6507187.jpg

See where "NCP" is, there in the centre of the reticle?  That's the North Celestial Pole.  Polaris is very near to the NCP, as you can see.  The scope is not illuminated however, unfortunately, but I think you can use a small torch to illuminate it.  You want to get Polaris, the actual star, within that tiny circle next to the word "Polaris".  The polar-scope itself, however, has to be aligned with the RA-axis, and that will be described within the instructions that should come with the scope.  Here's the reticle close-up...

1689144597_polarscopereticle.jpg.64683733f22ea5f9dd2e271c3f1b7eeb.jpg

Edited by Alan64
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11 minutes ago, Anthony1979 said:

Thank you.... Is that dovetail bar clamped correctly... it just doesnt seem right... Wont the scope slip off

You have got it right. It does seem a fairly basic way to mount a scope but it is the way it's generally done.

Tighten the clamp and the smaller security screw onto the bar firmly. It will mark the bar but thats what the bar is for.

 

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9 hours ago, Anthony1979 said:

What are these knobs for

DSC_0384.JPG

Those are for making fine side-to-side adjustments when aiming the mount-head, the RA-axis, towards Polaris.  You rotate the mount and tripod side to side roughly to line up with Polaris as close as you can with your eyes, then you use those knobs to fine-tune whilst looking through the polar-scope.  You may have to slightly loosen the clamp that attaches the mount-head to the tripod for it to work.  If so, then once you're aligned you tighten the clamp.

Oh, one more thing: with the "Star Discovery", only short timed-exposures are possible with the camera.  With an equatorial, and how accurately aligned you are with the NCP via Polaris, you can take much longer exposures, and in gathering that much more light at one time.

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Just another note on aligning the mount with Polaris before observing - a rough alignment of the right ascension axis with Polaris is sufficient for visual observing. I find that getting the "north" leg of the tripod (arrowed in the pic below) pointing in the direction of Polaris is sufficient to give reasonable tracking for visual observing.

Imaging is different - the alignment needs to be much more accurate which is where the small telescope built into the RA axis comes into play.

image.jpeg.355f8612c3d725ac00719abf2f1454cf.jpeg

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