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First telescope - NexStar Evolution 9.25" :-)

Celestron beginner cassegrain astrophotography accessories
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#76 JerseyBoy

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Posted 11 October 2014 - 09:08 AM

Some more pics  ;)

 

Attached File  Evolution 9_25 021.JPG   78.73KB   16 downloads

 

Attached File  Evolution 9_25 019.JPG   70.6KB   15 downloads

 

And as I set it up to show the neighbours, the clouds rolled it!

Attached File  Evolution 9_25 020.JPG   104.5KB   12 downloads


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#77 mclewis1

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Posted 11 October 2014 - 01:40 PM

Great pics, thanks.

 

Looks to me like there isn't really enough clearance with the side of the dovetail bar to put in some of the normal dummy bolts (some have wider heads than others). So it makes sense that there isn't anything in the holes. 

 

If it was my scope I might eventually find something to plug them with. It's certainly not any sort of priority but it might help keep little spiders and such from eventually setting up residence in the ota. You could also use a little black touch up paint to hide the silver rings where the paint has been removed. That way your eye won't be drawn to them.

 

Looking at your balcony setup I also might consider setting the tripod legs onto a piece of plywood with divots for the tripod tips (or maybe something to securely hold some anti vibration pads if you have them) so that you can comfortably move the scope a little further out towards the edge. Ever inch you can get will really increase the amount of sky you can view right overhead. If you have anti vibration pads and use them on their own consider tying a bit of string between all three, that way there's no chance of kicking one over that edge. Plus if you ever go to other sites it makes it easy to ensure that you have all three pads when you pack up in the dark ... it's very common for folks to leave one or more behind at a dark site.


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#78 JerseyBoy

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Posted 11 October 2014 - 02:03 PM

Thanks for the tips Mark  :cool:

 

I was thinking of using black plastic screw caps to cover the holes, the type you get covering screws and holes on flat pack bedroom furniture or fitted kitchen/bedroom furniture. The caps will be bigger but being plastic I can easily cut them to fit snugly against the dovetail. I can stick them in place with a tiny bit of mastic so they can easily be removed at a later date if required. 

 

POZI-COVER-CAP-BLACK.jpg


Edited by JerseyBoy, 11 October 2014 - 02:09 PM.


#79 Corncrake

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Posted 12 October 2014 - 05:09 PM

Thanks for the interesting pics JB,

and thanks for the infos etc in the NexStar area.

I am torn between the portability of the Evo6 or 8 and the apperture of the 9.25.

As you see from my sig I know some of the universe from using a (not so modern nor convenient) 6" already, so I ought to make a big jump, but will the 9.25 be a jump too far I wonder ! :)

Like Hick. earlier I have a (bigee) birthday coming up and am going to treat myself to something, , ,  I wonder if I can get both an Evo6 and an Evo9 past the domestic authorities ;) ?

 

Your balcony(ies?) look to be excellent location(s) for wind sheltered observing, I wonder what is below and is an expansion of the universe, distortion outwards in the space-time continuum, on the cards :) :)

 

These holes that you are discussing with Mark., are they not blind ? are they open to the innards of the tube ?

 

And it is raining again !


Edited by Corncrake, 12 October 2014 - 05:12 PM.


#80 mclewis1

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Posted 12 October 2014 - 08:55 PM

Those accessory mounting holes are indeed drilled right through. They need to be because for strength reasons you want the maximum number of threads ... the front and rear cells aren't that thick. Plus you can't pre determine the thickness of the accessory that will be mounted, so if these weren't drilled all the way through the accessories would have to have very custom length bolts (something nobody wants to do). Normally there are just short bolts in the unused locations.


Edited by mclewis1, 12 October 2014 - 08:58 PM.

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#81 JerseyBoy

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Posted 13 October 2014 - 05:10 AM

Hi Mark,

 

Sorry but the holes in mine are not drilled right through, they only go through the plastic, not through the metal.



#82 mclewis1

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Posted 13 October 2014 - 08:53 AM

Plastic ... there's no plastic. The rear cell is cast aluminum with a thick crinkle paint coating.

 

The holes should go through the casting but may be covered on the inside by the thin ota tube if it's inserted deep enough into the cell ... and if that's the case then folks who intend to add accessories like a wider D type dovetail (if someone was mounting the ota on a heavier mount) then they'd have to be really really careful about the length of the bolts (so no to deform the ota tube).


Edited by mclewis1, 13 October 2014 - 08:59 AM.

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#83 JerseyBoy

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Posted 13 October 2014 - 09:44 AM

Hi Mark, yes sorry it's metal, it just looks like plastic to me with that finish. On closer inspection in daylight the holes are not holes, they have been filled with what looks like a small tube. Imagine if you put a rivet in the hole and then ground the top off to make it flat, that's what it looks like.



#84 Dadadee

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Posted 13 October 2014 - 11:12 AM

JB, your pictures are great but they do not show how big that scope is in reality.  I was truely impressed the first time I saw one.



#85 JerseyBoy

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Posted 13 October 2014 - 01:10 PM

Dadadee, how about this one?

 

Attached File  Evolution 9_25 001.JPG   64.5KB   15 downloads


Edited by JerseyBoy, 13 October 2014 - 01:10 PM.


#86 Corncrake

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Posted 14 October 2014 - 07:05 AM

if you put a rivet in the hole and then ground the top off to make it flat, that's what it looks like.

Is it possible that it is a screw-in blanking plug ? Looking close at the central hole in the 'rivet', is it hexagon shaped to take an allen key / hex key.



#87 JerseyBoy

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Posted 14 October 2014 - 09:37 AM

Hi Corncrake, it's a round peg with a round hole in the middle. It's not blanking as it still leaves a hole, albeit only through the OTA tube.



#88 JerseyBoy

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Posted 14 October 2014 - 09:37 AM

 This should be of interest to everyone here, I just posted it.

 

http://www.cloudynig...e-ever-created/



#89 ebonrogue

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Posted 17 October 2014 - 01:42 AM

Hey jerseyboy one more question... With that litle clearance (while using the 2'' diagonal) do you find it hard observing near zenith?

Edited by ebonrogue, 17 October 2014 - 01:43 AM.


#90 JerseyBoy

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Posted 18 October 2014 - 05:26 AM

Hi  ebonrogue

 

Sorry not done any observing since the first day as it's just been rain clouds here. In any case I can't do zenith from my balcony as there is a balcony above. From where the 2" Baader zoom eyepiece ends up, a couple of inches out from the OTA/mount, I don't think it would be a problem. 



#91 mclewis1

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Posted 18 October 2014 - 01:09 PM

Hey jerseyboy one more question... With that litle clearance (while using the 2'' diagonal) do you find it hard observing near zenith?

Any alt az fork arm mount is going to have some issues when pointed close to the zenith. Larger scopes usually mean you have a wider base between the forks and that can get in the way a little bit. Generally though with larger eyepieces they stick out enough to prevent any real issues with your head placement.

 

But the bigger issue with any alt az mounted scope is that the zenith is considered a bit of a dead zone tracking wise ... you don't want to go there. Dob owners are usually very aware of this issue but even goto alt az mounts can have issues tracking in that area. It's just best to avoid objects close to the zenith for a little while.


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#92 ebonrogue

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Posted 18 October 2014 - 02:06 PM

Thanks for the info there mclewis... I just wouldn't want my diagonal hitting the base of the fork while I wasn't paying attention to it , although they might have already taken it into considetation and put a slew limit.

#93 RC4U

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Posted 18 October 2014 - 09:02 PM

you just have to put ota more forward on dovetail and it will clear....mine is just forward balanced with clearance to go straight down... but who would look at it that way...I guess not me but others need other views.. I would just put tripod in high front but then probably wouldn't track correct. but like I said I am not experienced and don't have the need to strain when viewing...to many other things to look at..jeff







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