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Question/Problem on a polaris mount

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#1 Brent Campbell

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Posted 26 December 2017 - 04:12 PM

I am trying out a polaris mount to see if its better than my current Alt/Atz mount.   I used the legs off of my Firstscope 80 Alt Atz - fit perfectly.   The problem I have is trying to mount my Celestron firstscope on the polaris with its original "funky" rings that came with it.  I have seen pictures of other polaris mounted C80s and they appear to have the same rings.

 

When I try to mount mine the rings are loose and won't tighten.    It appears that my saddle is slightly different than the ones on the C80s.  I think Vixen made two versions of this mount?  One for the reflectors and one for the refractors?

 

Polaris Mount Picture.jpg

 

 

Anyway has anyone ran into this before?   Solutions?  One I can think of is get a dovetail saddle from ADM and a new set of rings and a new dovetail - its just that will make this thing already too expensive for what it is.

 

   

 

 



#2 Nick Will

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Posted 26 December 2017 - 05:55 PM

Are they screwing directly into the mount saddle? They shouldn't. There should be threaded inserts in the saddle screw holes with detents on the underside of the sadddle for the ring screws...so as to pull the OTA snugly on the saddle.



#3 DreamWeaver

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Posted 26 December 2017 - 05:56 PM

Is it a close fit?  Something another layer of felt would fix?  Ace Hardware sells a green self adhesive felt that would stick to the original felt and help secure the OTA if gap wasn't to big.

 

Edit:  I think I misunderstood the problem and it's the rings are loose on the mount, and not the OTA in the rings, so disregard the felt.


Edited by DreamWeaver, 26 December 2017 - 06:20 PM.


#4 Brent Campbell

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Posted 26 December 2017 - 06:18 PM

The front ring is screwing directly to the saddle.  The rear ring is a compression ring.  The rings fit the oat but are loose on the mount.



#5 Nick Will

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Posted 26 December 2017 - 06:26 PM

It should have these inserts in the threaded holes in the saddle

IMG_2662.jpg

The slot is up and the detent is down..the ring screw end goes into the detent...pulling the OTA snug onto the felt lined saddle when the screw is tightened.


Edited by Nick Will, 26 December 2017 - 06:29 PM.

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#6 terraclarke

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Posted 26 December 2017 - 07:31 PM

Be careful you don’t overtighten those rings and that you have them on correctly beforehand. There is a reason they are called ‘tube-crushers’



#7 roscoe

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Posted 26 December 2017 - 08:01 PM

The knob/screws on both of the rings should push (upwards) against the inserts shown above... which are screwed into the tabs on the mount saddle from the [*] bottom up

So, they are sort of compression rings, but pulled downwards to tighten instead of being pushed into place like an EP thumbscrew does.

 

* I had this backwards....so have corrected it.  The inserts thread in from the bottom of the tabs, so the screwdriver slot end is facing up.


Edited by roscoe, 26 December 2017 - 10:42 PM.


#8 Brent Campbell

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Posted 26 December 2017 - 09:04 PM

That's what I'm doing wrong.  I'm missing the inserts.  Thanks.



#9 Moffett

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Posted 30 November 2018 - 10:09 PM

I just bought a C80 and the mount is missing these thread inserts too! Does anyone know of a source to buy them? It’s also missing the tripod spreader tray.

#10 telesonic

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Posted 30 November 2018 - 10:42 PM

For stuff like that, and the tripod spreader.. get ahold of Don Rothman at astro parts outlet. He's the go-to guy for these sorts of obscure things no longer in production. His list is pretty up to date, but sometimes it helps to chat with him as he keeps a large inventory.

 

I might have a set of those inserts kicking around in my spare parts box, doubt I will ever need 'em. I will look for ya tomorrow. 

 

T



#11 Bomber Bob

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Posted 01 December 2018 - 02:53 PM

Pack Rat vindicated:

 

Polaris Mount - Cradle Divets P01.jpg

 

Found a couple of pairs of these in the shed this morning -- probably from cannibalizing...

 

Y'all still need 'em??



#12 Moffett

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Posted 01 December 2018 - 10:51 PM

Thank you BB. Sent a PM.



#13 toby493

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Posted 04 December 2018 - 10:17 AM

I;m  trying to  find a saddle  for my Eq2 mount for my meade 390



#14 toby493

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Posted 04 December 2018 - 10:17 AM

I;m  trying to  find a saddle  for my Eq2 mount for my meade 390

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  • meade-390-saddle.jpg



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