Nippon
member
Reged: 10/22/09
Posts: 54
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Though I really like my 8SE's goto and the always upright eyepiece plus easy access to any area of the sky. There are times when I would just like to set up my Vixen Polaris,just plop it down with the RA axis pointing north and observe planets. My Polaris is the original that predates the Super Polaris. I put a Vixen/CG5 dovetail clamp on it years ago and I have enough counterweights to balance the weight of the 8SE tube. Has anyone used this mount with an 8" SCT long term? Is it up to the task of safely carrying that big a tube?
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Tel
Post Laureate
Reged: 03/31/06
Posts: 3984
Loc: Wallingford England
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Hi Nippon,
No.
Placing an 8SE OTA on the Vixen Polaris mount is not to be recommmended. This GEM is too flimsy and its payload relates only to a maximum of around 10 lbs. The 8SE OTA alone is around 12-13lbs without accessories and is normally around 19 lbs with the necessary addition of a finder, diagonal, eyepiece and dew shield etc.
Best regards,
Tel
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Truth is the cubed root of Verbosity.
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Nippon
member
Reged: 10/22/09
Posts: 54
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I have never been able to find any stated payload capacity for the Vixen Polaris. Celestron used to market it coupled with the Vixen R150 Newtonian as the C6 which later became the SPC6 after the SP mount replaced the Polaris. Does anyone know the payload capacity of the Vixen Super Polaris?
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Tel
Post Laureate
Reged: 03/31/06
Posts: 3984
Loc: Wallingford England
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Hi Nippon'
Do these links help ?
http://www.astromart.com/articles/article.asp?article_id=465
Describes the Vixen Polaris' payload as ca. 10lbs.
&
http://www.laughton.com/paul/rfo/ss2000/spgp.html
Describes the Vixen Super Polaris' payload ca. 16lbs.
Best regards,
Tel
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Truth is the cubed root of Verbosity.
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Nippon
member
Reged: 10/22/09
Posts: 54
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Yes, thank you. I have read threads and reviews that state 10 pounds for the Polaris but I also read a thread that said the Polaris and the Super Polaris had the same payload capacity and that the redesign to the SP was to accommodate a declination motor. I guess I could just give it a try with the SE8 tube and see if its movement feel like they are under to much load and if it gives steady views. If it still feels silky smooth like it is with my 9 pound refractor with about the same amount of force to move the scope by hand and is nearly as steady then it should be okay, right?
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Tel
Post Laureate
Reged: 03/31/06
Posts: 3984
Loc: Wallingford England
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Hi Nippon,
I can't subscribe to this being "right" because I've no direct experience that it might or might not work.
I would say however, that while it functions with your 9lb refractor,(as you would expect), that's a far cry from loading this GEM with a ca. 19+ lb 8SE OTA with all its necessary accessories. Even the SP is only rated with a payload of 15-16lbs max. which I feel a modestly equipped 8SE OTA would easily exceed.
Just one guy's opinion of course based equally on what I've read and posted. Yours may well differ.
Best regards,
Tel
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Truth is the cubed root of Verbosity.
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Nippon
member
Reged: 10/22/09
Posts: 54
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You are probably right. Its a pity though, it is such a well made old mount. I have had it since 1988.
Thanks, Nippon
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Tel
Post Laureate
Reged: 03/31/06
Posts: 3984
Loc: Wallingford England
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Ideal perhaps for astrophotographical use with a wide field, short focal length refractor ? 
Best regards,
Tel
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Truth is the cubed root of Verbosity.
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watcher
sage
Reged: 11/21/07
Posts: 406
Loc: NJ
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Don't hold me to it, because my memory isn't what it used to be, but I think I remember reading in the mounts forum, that there is a part of the Polaris that would actually bend under too heavy a load.
Joe
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(quote)"That does it! Next Big Bang, someone has got to rethink this gettin' old business!" Joe Daugert
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1986 Celestron c-8 (retired)
Celestron Omni XLT 120
Celestron Astromaster 70 AZ
Vixen GP2 mount on Omni XLT tripod (soon to be driven by iOptron GOTO Nova)
Meade 16x50 binoculars
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Nippon
member
Reged: 10/22/09
Posts: 54
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Your memory is correct. The part in question is the bracket that holds the altitude adjustment screw. Mine bent about 20 years ago but I fashioned one from the steel part that held an odometer/speedometer to an exercise bicycle. It was practically made to order and I have had no problems ever since. The original part would hold position okay but would bend if you tried to raise the altitude with just the screw. As long as you helped it by grabbing the counterweight shaft to lift the load it would be okay. Here is a photo of the fix if anyone has the same issue.
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Nippon
member
Reged: 10/22/09
Posts: 54
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Opps, the photo
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watcher
sage
Reged: 11/21/07
Posts: 406
Loc: NJ
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Thank you.
Joe
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(quote)"That does it! Next Big Bang, someone has got to rethink this gettin' old business!" Joe Daugert
-------------------------------------------------
1986 Celestron c-8 (retired)
Celestron Omni XLT 120
Celestron Astromaster 70 AZ
Vixen GP2 mount on Omni XLT tripod (soon to be driven by iOptron GOTO Nova)
Meade 16x50 binoculars
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jrford
member
Reged: 08/25/05
Posts: 80
Loc: Birmingham, MI
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i actually did this, that Polaris was a fairly 'strong' mount. The only reason why i went to the Nexstar is for the GOTO's, and the ep was to low for me and my back. Tracked well, no vibrations, damping times sub 1 second. GOTO's are essential in my location due the massive amounts of light pollution, star hopping was impossible.
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Black Celestron 8" on a Nexstar using Rays Brackets
Celestron 4mm,6mm,9mm,15mm,26mm,32mm
GSO 20mm, GSO 2"-26mm,30mm,42mm,50mm
Pentax PCF WP 10X50
Barska 10x50,12-36x70 ZOOM,8x25 WP
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Nippon
member
Reged: 10/22/09
Posts: 54
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Thanks for the photo, How long did you use the C8 on your Polaris?
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jrford
member
Reged: 08/25/05
Posts: 80
Loc: Birmingham, MI
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I used it for a couple of months. The mount actually came with the refractor on top (free), I came across a deal for the OTA which i picked up separately. I believe that there is a better way to mount a C8 then with rings. I found the tube rings for like $30 so i went with them. It was used only for Visual with a 1-1/4 diagonal and EP, i never did any imaging with it, or loaded it up with a bunch of accessories. The extra counter weights i made with celestron's current weights but i had to re-drill and tap for the threads (16mm?), its really optional as i also used dumbbells from an old weight set that worked well too. I think the total was 14.5lbs. I never changed the latitude setting but for the first light, i did as suggested above and helped along, and then lowered it with the screw.
Only problems i experienced was the EP was to low at most angles to view comfortably (for my old back); also my limiting mag. was about 4.0 in my area so star hoping was impossible for the most part; fully setup it was about 30-40lbs not light by any means but do-able for 20 feet. It was a solid mount but there was no way to add DSC or Goto.
So, now I'm using a NexStar mount with it, which for me offers more grab and go (10lbs lighter), higher EP and Goto.
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Black Celestron 8" on a Nexstar using Rays Brackets
Celestron 4mm,6mm,9mm,15mm,26mm,32mm
GSO 20mm, GSO 2"-26mm,30mm,42mm,50mm
Pentax PCF WP 10X50
Barska 10x50,12-36x70 ZOOM,8x25 WP
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Nippon
member
Reged: 10/22/09
Posts: 54
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I know what you mean. having the eyepiece always up and traveling in such a short arc at a comfortable height is a blessing. I just think it would be nice at times to use the Polaris and I was hoping it would be usable as a backup should the NexStar mount ever need to be sent off for repairs. Thanks for the info
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