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Got my Skywatcher 250 FlexTube! :)


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Woooooo!

Finally went and picked up my new Skywatcher 250 FlexTube!

Just finished the assembly now,

I must say that the assembly of the base took longer than I expected (like 25min), but that must be because I don't usually assemble things, and I wanted not to break anything.

a5cvgV6s.jpg Q9f9f6ts.jpg uZ9GOnbs.jpg 8D2ovZSs.jpg twRupozs.jpg bzkutSqs.jpg 8XBXyIXs.jpg

I also bought a 4mm SWA 58° Eyepiece:

RMnPLt7s.jpg

And an Orion Laser Collimator:

PvbAKuns.jpg

I do have some questions please :)

1) I think I closed the rotating base's main screw way too strong (cause I couldn't rotate the base at all), so I loosened it up a bit... it's still kinda hard to move with a nudge, but how do I know that it's not too loose if I keep loosening it?

2) What are these black screws for? k684gOKs.jpg I know the silver ones are to lock the flex tube bars, but no idea what the black ones are for...

3) What's this? 5XY2pmds.jpg I think it's a 2" adapter.... but why would I need a 2" to 2" adapter? Is it just to take the eyepieces backwards a bit for the focus point? (maybe because of the built-in DSLR option?)

Thank you!! :)

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Lovely scope ! great choice...

1 - tighten nut with a couple of sheets of paper under washer, then back off until you can pull the paper out 

2 - No idea ...

3 - yep, its to keep the distance correct

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The black screws have a spring behind them and a ball bearing in front of that. When you slide the trusses out you'll hear the three ball bearings click into the holes on the trusses to hold it in place. Then you lock the trusses in place using the "T" bar screws. The whole lot together helps to maintain collimation.

The 2" adaptor is to enable use of 2" eyepieces. You can't use them without it - same for the 1.25" adaptor. You'll notice they both have a flange at the end which holds them on the focuser tube when you tighten the screws on the focuser. The screws on the adaptors hold eyepieces in place.

Hope that helps and congrats on your new scope. :)

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Both replies were great help, thanks!

Gonna loosen the main rotation screw according to Knobby's suggestion now.

Brantuk, I miiiiggght have accidentally tightened those black screws a bit... are they supposed to be tight? loose? "snug"? somewhere in-between? thanks!

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Hi Congts on your new scope. I got a SW 200P Dob yesterday, so haven't had it out to stargaze yet.  Just out this evening to focus it at a distant chimney pot. I got the 2" adaptor as well.

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Well - the black screws are factory set and not supposed to be touched. Mine had some very sticky tape over them. But I got curious cos there was no mention of this and I removed the tape and unscrewed them. Spent the next hour chasing ballbearings round the floor lol.

If you adjust them often enough you'll get a feel for how firm they should be. I set mine just firm enough to click in place when the trusses are raised - but loose enough that it only required a gentle push to slide them back down. :)

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Thanks Purdo! :) I'm also gonna learn how to collimate / focus / etc tonight!

Brantuk, thanks for the info. So if I understand things correctly, those black screws + ball bearings are there to keep the tube from collapsing while you unscrew the T-screws?

If that's the case, then I loosened them just enough, to behave as you said. Awesome!

Thanks again!

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Lol I've seen so many videos about collimations,

but I never imagined that with every turn of the allen key I'd feel like I'm breaking the entire secondary mirror holder :)

I think I have things collimated correctly now, but I will say that I still have no idea which allen adjuster moves the secondary mirror to which way...

it kinda felt like that as I'm turning the allen key, the laser point goes down a lot, but when I release it, it ends up a little higher than before.. weird stuff :)

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The 2" adaptor is to enable use of 2" eyepieces. You can't use them without it - same for the 1.25" adaptor.

Just to clarify... Do I need to connect the 2" to 2" adapter and only then connect the 1.25" adapter? or did you mean that the 1.25" adapter acts like the 2" adapter, but for 1.25" eyepieces?

Thanks.

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Hi,

You use the 1.25 inch adapter for 1.25 inches only in the focuser, and the 2 inch tube for 2 inch eyepieces only, in other words, there is never a need to put the 1.25 inch extension tube into the 2 inch one.  One or the other attaches to the focuser depending on your eyepiece. Right now you only have 1.25 inch eyepieces with what you bought, so you will not be using the 2 inch extension tube until you decide to buy a 2 inch eyepiece.

Congrats on the scope. :smiley:

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Congratulations on your new scope  :smiley:

You have had some great advice above. Mine would be to get used to it with the 25mm and 10mm eyepieces initially as the 4mm, will give 300x, is probably too much on many occasions so might give you a false impression of the scopes abilities (ie: the image will not be as crisp as you might expect). It will be useful on the Moon under good viewing conditions in due course.

Finding things with a 4mm eyepiece is also quite a challenge because it only shows a tiny piece of sky.

Otherwise, I hope you enjoy the scope !

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Thanks for the advice, John! 

I do have the 25mm connected at the moment, as I figured it would be best to work my way up in magnification :)

And that's truly an inspiring quote of John Dobson that you've put there... I've seen (most of) his documentary, and I would want to do some sidewalk astronomy myself someday soon.

(I also talked to the store manager where I bought the scope, since I found out recently that he arranges sidewalk astronomy events.. but it would also be cool just to take the telescope to the sidewalk outside my house on a nice evening).

And thanks m37! Can't wait to test it out :)

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First light... WOW!  :shocked:

Ok, that was pretty amazing!

Me and my old man went out to the front yard under intense street-lights, but man, the moon looks AWESOME!

I've never seen it like that with my own eyes... and it was sharp!

I assume it can look sharper, since my collimation was a bit off after collapsing and extending the tube and moving it around a few times.

I also don't know if I've let the mirror cool enough... but I don't really care right now, I'm still replaying what I saw in my head :)

Even when looking through the finder-scope, my eyes got wide open suddenly and it was already great (I don't think I ever looked at the moon even through binoculars.. not that I can remember at least.. only naked eye until now).

With the 25mm eyepiece I could see the entire moon... really beautiful!

Then I zoomed in some more, and then some more... amazing.

Here's a crappy picture I took with my phone held against the eyepiece (25mm)

LqxPTug.jpg

And some close-ups with the 4mm eyepiece 

8x2npAcs.jpg g2uNTnVs.jpg

And here's a pic of my old man, looking at the moon through the telescope under all the streetlights.

He was also very amazed, and wouldn't let me back in the chair for a long while! lol

ZOeLdRys.jpg

At around 4 AM, clouds starts to cover the sky, so I had to call it quits...

but I would call it an amazing first night with the scope!

A few questions, please :)

1) I noticed that the scope keeps sliding down, even if I tighten the handles really tight. At first I assumed it was the rotation of the earth, but it seems too fast... is there a "trick" to it? The only thing that kinda worked was to move the scope up a lot, and then slide it down slowly to the desired spot.

2) Is it normal for the 3 small floor-feet at the bottom of the base to wiggle around? The screws seem to be closed tight, doesn't look like the feet can fall off at all, but they are wiggling around when picking up the base.

3) I noticed some stuff on the primary mirror when I looked at it closely... I assume it's that larger "stuff" that normally floats in the air (which is 80% dead skin cells, btw). But it made me wonder... How often do you clean your primary mirror?

Thanks!

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That's a really cool picture!

To answer your questions:

1. Your scope probably needs a bit of weight at the back to balance the tube. Undo the handles while supporting the tube, it should sit horizontal to the ground without moving. I used one of those leg weights from a keep fit store with the webbing from a guitar strap to secure it to the tube. Magnets are another option.

2. They should be secure. Get the right sized screwdriver and apply plenty of inward force to avoid mashing the screw head before turning slowly until nice and tight. Takes a bit of strength!

3. Don't worry about it! Takes a lot to affect the viewing. Don't even think about cleaning the primary until there are dead birds and stuff blocking it completely ;)

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Nice pics soundwave - pretty darned good for a total newbie. :)

I notice you have a lot of street light at your location. I'd suggest using a dew shield and shroud. Make the dew shield from a black foam camping mat. You can get them for a fiver at your local camping shop - they're over thirty quid from astro shops. The shroud you can also make - but I bought one for my 300P Flextube - you'll find it here:

http://www.firstlightoptics.com/dew-prevention/astrozap-light-shroud-for-skywatcher-flextube.html

The Astrozap ones are tailor made and really very good. For collimation - you should order "Bobs Knobs" - you can get them from a distributor if you can find one - or direct from the USA - mine arrived within a week - they make collimating the secondary an absolute breeze:

http://www.bobsknobs.com/Newt/page66/SWdob.html

There are all sorts of counterweight devices about - I used to use a 2kg magnet wrapped in foam and duck tape. I still use it but on a different dob now cos I sold the 300P. Cleaning the mirror seems like a massive job first time round - but the good news is you won't need to do it for a year or two unless adverse conditions dictate.

I rinse mine under the warm water tap first for five mins to loosen the any impurities. Then using lint free cotton wool and warm water with a dash of pure soap wipe the mirror by dragging the cotton wool under its own weight from the center outwards. Then three rinses - first under the tap to remove the soap, then with distilled water, and finally with isopropyl alcohol.

Inspect closely at each stage to ensure you aren't leaving any smears or marks behind you. But it really does need to be filthy before you have to clean it. :)

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That's a great scope you have bagged yourself.

By the looks of your images we seem to have a budding astro photographer amongst us, well done.

BTW I notice you use a seat to observe, so many start out crouching/standing, it really makes a big difference being comfortable and steady at the eyepiece.

Good luck for your future with this wonderful hobby.

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Thanks, Astro Imp!

Actually, the seat came into play when my dad joined in the session, but I did find it MUCH more comfortable! ...I just didn't think about it at first :)

Tonight is meteor shower, right?

I wonder if the moon is also in the path of the comet's tail.. Although I would assume the asteroids are pretty small, and without an atmosphere to burn them up, they probably won't be visible, unless they kick up a LOT of dust somehow.

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And it also doubles as a space-shuttle  :shocked:  Niceeee!!

I am planning on making a shroud and dew-shield using a camping mat at first.

If I'm not satisfied with the results, I might get some Black Flock fabric and make a shroud from that (or buy a commercial shroud).

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20:15 PM  to  21:15 PM...   JUPITER! (amazing)

My brother and I set up the telescope in the yard again, located Jupiter (a bit low in the sky), and looked through the 25mm.

While Jupiter appeared small, we could still make out 2 tiny bands across Jupiter, which amazed me completely, because I expected to see a "ball of light" at this magnification. 

We could also see a few of Jupiter's moons, 

Going to 10mm -- In my opinion, this was the best view of the 3 eyepieces. I could clearly see the bands, and could make out their jagged edges. Truly awesome!

Going to 4mm -- Jupiter did seem bigger, but I couldn't get it to focus as sharply as the 10mm... I did see the bands, but it didn't look REALLY sharp...

A question regarding this picture I took:

L6k595h.jpg

This is a really blurred out Jupiter... 

To my understanding, when un-focused, it should look like a perfectly round doughnut, but there are "bites" in this doughnut...

1) Does this mean something bad?

I do hope this is due to Jupiter's moons interfering with its own blur... But I'm not sure at all (and haven't tried this on a Star, yet).

Also... There are 2 visible marks on the image (circled here)

YeL6XDos.jpg

And on a different try, I've also seen some on the bottom-left side of the field of view...

2) Should I be worried?

Thanks!

...and to close on a happier note... here's my brother looking at Jupiter [seen above him]

E1dmnBVs.jpg

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One of the 'bites' is the focuser poking inside the tube... Wind it out and it won't show , the others are possibly the mirror clips.

no... Don't worry, carry on enjoying the scope :-)

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Yup - it's the focuser tube and primary mirror clamps. The two blips are less easy to diagnose - could be anything from sweat spots or grease spots, to dew containing impurities of some sort that have stuck. The picture is way out of focus - so long as they don't show when in focus then there's no need to clean it.

You'll be amazed how mucky the mirror can get before the view is seriously degraded and needs a mirror clean. :)

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