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Has anyone installed an EdgeHD 8" on a 6/8 SE mount?

cassegrain
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#1 FC1963

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Posted 04 July 2020 - 10:02 AM

If I should get the combination it will be mainly used as very portable telescope doing mostly visual observations and occasional AP with a wedge.

 

If anyone has done so, do you have pictures and what was your experience?



#2 coopman

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Posted 04 July 2020 - 10:27 AM

This combo would likely have clearance issues with the back of the OTA and the top of the mount's base.
The Evolution mount arm is a bit taller to better accommodate the Edge OTAs.

#3 coopman

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Posted 04 July 2020 - 10:32 AM

What I did was to buy the Evo 6" rig and sold the 6" OTA and kept the mount.  I already had an 8" Edge OTA for several years before the Evo came out.  The 6/8 SE mount is overloaded with a regular 8" SCT OTA on it and the 8" Edge OTA is even heavier.


Edited by coopman, 04 July 2020 - 10:35 AM.

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#4 JohnBear

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Posted 04 July 2020 - 11:03 AM

+1 for Coopman.

Since the SE will be technically overloaded, balancing the OTA (and associated equipment) will be critical for keeping the mount in good working order.



#5 3 i Guy

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Posted 04 July 2020 - 11:45 AM

I use the combo you’re asking about and I agree with Clay. It’s OK for visual but pretty shaky at higher powers when you’re focusing. I think a motorized focuser would help but I haven’t pulled the trigger on one. It makes a pretty good outreach combo because the goto’s are accurate and it’s lightweight but I would look at the EVO if photography is in the cards.


Edited by 3 i Guy, 04 July 2020 - 12:00 PM.


#6 Bataleon

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Posted 04 July 2020 - 02:03 PM

Weight issues aside, I have serious doubts about the ability of the SE to track well enough for imaging anything but the moon.

Sent from my SM-N960F using Tapatalk

#7 Supernova74

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Posted 05 July 2020 - 04:48 PM

personally I think the Celestron 8” Edge HD should be fine on the 8se single fork mount.even tho the edge is a little heavier than the standard C8 OTA it’s not a very long tube and centre of gravity will be about the same and definitely shouldn’t put more strain on the motor drives.just make sure it’s definitely an 8se fork mount as the 4se,5se has smaller fork and less 

payload capacity.regarding clearing the forks closer to the zenith is what you need to watch out for!? Just make sure if your useing a diagonal it clears the bottom of the fork mounting.i can also imagine the edge HD (don,t quote me on it tho) it’s more back end heavy and you might be able to move the OTA further up the dovetail bar and use some kind of counter weight system underneath the tube(to find a better balance! And make sure your diagonal and EP is also in before you balance)


Edited by Supernova74, 05 July 2020 - 04:52 PM.


#8 gravy11

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Posted 16 July 2020 - 11:11 PM

Not sure if this is in the same wheelhouse....I’m new. Would a Celestron C8 be ok on a Celestron 6SE Mount?

Thx!

 

Dan

 

P.S. There are so many different models it can get confusing....



#9 Supernova74

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Posted 17 July 2020 - 10:30 AM

Hi dan 

the answer to your question is yes the C8 would be fine on the 6se mount as it’s the same as the 8se mount 

the only ones in the series it would not be advisable to put on is the 4se,5se mount.



#10 SeattleScott

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Posted 17 July 2020 - 11:25 AM

Yes a standard C8 is adequate with the SE mount. Some vibrations but ok if you aren’t picky. Do note that there are clearance issues if you want to do anything fancy like adding a reducer or 2” diagonal. It can be done but it can get interesting.

Scott

#11 Nippon

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Posted 17 July 2020 - 11:41 AM

The Edge 8 is significantly heavier than the standard C8 plus the visual back is much longer that a standard C8's. So you would be at least a couple of pounds over the 12 pound capacity of the mount and the standard C8 barely clears the mount base.  


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#12 Supernova74

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Posted 17 July 2020 - 11:57 AM

Yes a standard C8 is adequate with the SE mount. Some vibrations but ok if you aren’t picky. Do note that there are clearance issues if you want to do anything fancy like adding a reducer or 2” diagonal. It can be done but it can get interesting.

Scott

Yes I know what you mean there had the same problem with my Meade.as my dealer sold me the wrong flanged moonlite focuser so still waiting for shorter flange.however with the C8 on Nexstar se mount you can always move the OTA further up the dovetail clamp and if need be add a small counter weight on front of the tube to counter balance more efficiently!?



#13 FC1963

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Posted 17 July 2020 - 12:07 PM

Yes a standard C8 is adequate with the SE mount. Some vibrations but ok if you aren’t picky. Do note that there are clearance issues if you want to do anything fancy like adding a reducer or 2” diagonal. It can be done but it can get interesting.

Scott

Here is the solution:

VC8-XL- V Series Dovetail Bar for Celestron 8" SCT Telescope. Extra Long

https://www.admacces...ope-extra-long/



#14 mclewis1

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Posted 18 July 2020 - 08:10 AM

I wouldn't worry about this too much as the SE mount isn't suddenly going to stop working with an extra pound or so of payload,  but if I was doing this I'd certainly practice getting a good balance and make a few other changes.

 

Remove the 50mm finder and use a simple (lighter) red dot finder for helping with the initial alignment.

 

Remove the Edge 1.25" visual back and use a 2" SCT threaded diagonal. This of course won't save any weight ... actually the opposite but it will reduce the potential interference with the base when pointed at higher altitudes. The small amount of additional weight is however in the best place to help keep the OTA positioned as far forward as practical, which will also help with potential base interference.

 

The 2" diagonal will place a 1.25" eyepiece at about the same spacing behind the Edge's rear cell preserving the optimal optical position. I'd also stick with smaller lighter weight 1.25" eyepieces. So stay away from the physically large 90-110° stuff, and instead stick with the smaller popular 65-82° 1.25" models.

 

I'd also hang another 10-15lbs of weight from the spreader bar, this will help dampen vibrations and oscillations when focusing.

 

I'd probably add the relatively light weight Celestron motorized focuser. I think it's small extra weight "penalty" will be more than offset by the decrease in vibrations when fine focusing at higher magnifications.

 

I would entirely forget the idea of a wedge under the SE. Instead if you really want to do a little imaging I'd use as sensitive a camera as possible and keeping the exposures to a few seconds and use deep stacks with rotation mitigation (image alignment). I might also consider a Hyperstar setup for very high speed short focal length imaging ... but in general I think a good quality small apo with a flattener would be a better idea used in place of the 8" OTA for short focal length imaging on the SE mount.

 

The overall success in imaging with an SE mount will depend more on the physical characteristics of your particular mount (amount of backlash in the gears) than any add on hardware you might consider. If your SE is a poor example tracking wise there won't be anything you can add to it to improve things. The fix to this would be stepping up to the Evolution or similar mount.


Edited by mclewis1, 18 July 2020 - 08:13 AM.



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