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Explore Scientific N208CF Rings, Vixen plate

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#1 strelnikoff

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Posted 20 July 2019 - 01:40 PM

I've just received Explore Scientific N208CF Newtonian telescope. As a serious step-up from my 6" Celestron - in quality as in price - it made me re-think pro's and con's reflector/refractor. 

Regardless, this is a forgiving wide angle telescope with 812 mm focal length and nice f/3.9,

 

However, when I got it - (from Adorama through Amazon - and I can say few con's about UPS here) - I've noticed few problems. Or - I think these are the problems.

 

First one - the clamp, rings and namely Vixen dove-plate are ... well, I'm not sure if this is on purpose, or it is just poor manufacturing.

Before I start working on this - if it is a problem - I better ask here: is this normal???

 

IMG_5780.jpg

 

IMG_5781.jpg

 

Also - when I look straight at it - it is off center (in addition to not being in contact with ring assembly):

 

IMG_5791.jpg

 

 

 

Second problem (not that big of a deal) is - secondary mirror had set screws loose, collimation is/was out which in itself is not that big of a deal. One thing I found that is a big of a deal is how locking set screws of the secondary mirror are loose within their threads (in receptacle port). I may have to add some wax just so there is some friction and they don't play or fall out. 

 

 



#2 strelnikoff

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Posted 20 July 2019 - 01:50 PM

and last one I've noticed (and this is casted so ... not casted well perhaps) there's an angle between vertical axis and one of the bottom parts of the ring/clamp.

 

IMG_5783.jpg

 

 

The OTA feels secure and stiff, but - last night I've added used it on friends 10Micron GM1000HPS mount, and it was balanced well, but the orthogonality was... off. No wonder with such a small contact between mount and telescope. 

 

So - any suggestions? Is this normal? Should I - and what should I - do with the Vixen plate... ?


Edited by strelnikoff, 20 July 2019 - 01:51 PM.


#3 junomike

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Posted 21 July 2019 - 09:21 AM

Probably not a huge deal but I wouldn't accept that If bought new.



#4 Chris Johnson

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Posted 21 July 2019 - 12:36 PM

Remove the rings from the tube assembly. Back off the 4 Phillips head screws until they are below the level of the Vixen bar and tighten the center Allen head screw until the bottom of the rings are in contact with the Vixen bar and at a right angle with the Vixen bar. The ring with the red arrow is not at a right angle. Finally tighten the 4 Phillips head screws. They allow you to adjust the center line of the tube with the polar axis.



#5 iKMN

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Posted 21 July 2019 - 12:49 PM

If bought new I would bet ES will replace those rings and dovetail plate if you contact customer service.

#6 strelnikoff

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Posted 21 July 2019 - 05:01 PM

Probably not a huge deal but I wouldn't accept that If bought new.

 

 

If bought new I would bet ES will replace those rings and dovetail plate if you contact customer service.

 

I will contact them and see what they have to say. I may have to do a review of the telescope in few weeks after I have sorted out all the kinks and used it in few sessions. 



#7 strelnikoff

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Posted 21 July 2019 - 05:26 PM

Remove the rings from the tube assembly. Back off the 4 Phillips head screws until they are below the level of the Vixen bar and tighten the center Allen head screw until the bottom of the rings are in contact with the Vixen bar and at a right angle with the Vixen bar. The ring with the red arrow is not at a right angle. Finally tighten the 4 Phillips head screws. They allow you to adjust the center line of the tube with the polar axis.

I did that - thanks! On one ring it worked, second one - one of the Phillips head screws had damaged receptacle for Allen wrench (phillips cross head). So - one is in contact the other one is not. Honestly, considering how off the rings are, I doubt that it would matter in terms of alignment with Polar axis. 

I may play with that once I take the scope out and do polar alignment. At 812 mm focal length, it will have less of an impact vs. longer focal lengths. 

I think this is the last Newtonian for me - for a while. And I haven't started using it yet properly.

 

I'll still write to ES to see what they have to say.




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