11 replies to this topic

[lapsmith]

The Nexstar 5 that I bought new about 25 years ago has a bad hand controller.  I've tried all the possible fixes for the LCD but no joy.  Upgrading the HC alone is not possible with these older unit so my options are:

 

  A. Upgrade the circuit boards (as described here)and buy a new hand controller.  Cost $250 - $300

  B. Buy a used 6se mount, and a dovetail (if I can even find one) to mount the original OTA.  Cost $300+

  C. Sell/donate the 5 and buy a new or used complete 6se.  Cost $750 and up

 

I don't mind spending the extra for the 6se, if there would be an improvement from what I had when it was working.

 

My questions are:

• Are the original Nexstar mounts worth upgrading?  I've read somewhere that they are better than the SE mounts (better motors, less backlash).
• Is there much difference between the 5" OTA and a 6se OTA?  The latter would be brighter, but I wonder if the optics are otherwise comparable.
• What would you recommend?

 

My use is casual amateur and I don't think I need to go up to the 8se, especially since I've read the mount is marginal for that size OTA.  I do want the convenience of computerized and will also add the star sense camera to whichever I choose.

[StephenVP]

Hi, Lapsmith and welcome to cloudy nights!

The 6 & 8 SE are one in the same mount. They use the same SE mount for both sizes and I have tried an 8" on it. No, it doesn't work for beans in my opinion but the 6" SCT rides the SE mount quite nicely.

I've never used an original Nexstar mount so I can't compare but the SE does have backlash adjustment settings.

~Stephen

[Martinbruce]

I have a 6se and an Evo 8. The Evo mount and tripod are substantially better, less wobbly perhaps even stiff. However were I in your shoes I would consider using your 5” OTA on one of the newer mounts. There are plenty new mounts that will allow you to swap out a SCT OTA with a Newt or refractor. One mount, multiple scope types if you want, or not if you choose. Go to, AltAz, GEM, EQ, or hybrids. It seems like a golden era in mount development and choices now. The CN classifieds might provide you a cost effective way to go. Good luck. 

[fullthrottle_man]

If it's an original Nexstar 5 (from the 5/8 and 5i/8i series around the year 2000), it has a flat plate for mounting instead of a dovetail. I have an original Nexstar 8 OTA myself. You'll need a retrofit dovetail specifically for the original 5/8. I got mine from eBay.

[mclewis1]

...

 

My questions are:

• Are the original Nexstar mounts worth upgrading?  I've read somewhere that they are better than the SE mounts (better motors, less backlash).
• Is there much difference between the 5" OTA and a 6se OTA?  The latter would be brighter, but I wonder if the optics are otherwise comparable.
• What would you recommend?

I would say yes those original mounts were pretty good (but not NS GPS/CPC good)  - smoothness/backlash wise. This is anecdotal from the user base and use, but I haven't owned an original NS5/8. I believe that the motor gearbox used was a bit better quality on these earlier mounts.than on the later SEs (so a bit better backlash characteristics). I'm not sure any of this would make much of a difference to a visual user unless you happened to be comparing to a poor mechanical example of an SE (unfortunately not too uncommon).

 

The optical differences would really come down to the optical quality of each example. The C6s have generally been quite to very good with very few lemons. In addition to the aperture difference the coatings are better on the C6s (they're all XLT) and your much older C5 mirror would likely have degraded a bit so I think you'll easily notice the difference in brightness. So if you're a mixed (DSO and solar system) observer the C6 would be a significant upgrade, if however you have an optically really good C5 and you are primarily a solar system observer then perhaps it wouldn't make as much of a difference.

 

I think the direction for an upgrade will really depend on a) your budget and b) you're electrical/mechanical capabilities combined with a level of patience. 

 

So if the money isn't really an issue I personally would sell the NS5 and jump over an SE and right to a Evolution 6. While a bit more expensive the operation of that mount is better than the SE and I sense that you might find that really of value to you.

 

If however you have the expertise and patience to work with the electrics and you want to save some money. then the upgrade thread IMHO contains a great roadmap. I would also seriously consider (as SieglindeFestkochend has) to also add one of Mlord's homebrew DIY boards ... I might even consider doing one if I bought a new Evolution (adding GPS and some additional connectivity options). 

 

But don't underestimate the patience required to go through the board swap - if you get it working first time then fine but you could find that troubleshooting the upgrade sucking up a lot of time and possibly additional monies.

Edited by mclewis1, 13 February 2025 - 09:28 AM.

[lapsmith]

Thanks Stephen!  I neglected to introduce myself, how rude!  My name is Tom, I am a retired NASA engineer and have only owned the Nexstar.  I haven't taken it out in several years but now that I am settled in the new house, I have some time for this hobby.  I don't see myself getting into AP, buy you never know.

 

I didn't know the SE has backlash adjustment.  I honestly don't remember if the 5 was adjustable, but it did have some backlash, though never enough to be annoying.

 

 

Hi, Lapsmith and welcome to cloudy nights!

The 6 & 8 SE are one in the same mount. They use the same SE mount for both sizes and I have tried an 8" on it. No, it doesn't work for beans in my opinion but the 6" SCT rides the SE mount quite nicely.

I've never used an original Nexstar mount so I can't compare but the SE does have backlash adjustment settings.

~Stephen

[lapsmith]

Thanks, I will look into the Evo mount, though not sure if it is in my price range.   I definitely want to stick with a Goto and SCT for ease of use and portability.  But maybe as I get further into this, things will change.  Would a 6se mount easily accept other OTA's?  Does anyone besides Celestron make fully automated mounts?

I have a 6se and an Evo 8. The Evo mount and tripod are substantially better, less wobbly perhaps even stiff. However were I in your shoes I would consider using your 5” OTA on one of the newer mounts. There are plenty new mounts that will allow you to swap out a SCT OTA with a Newt or refractor. One mount, multiple scope types if you want, or not if you choose. Go to, AltAz, GEM, EQ, or hybrids. It seems like a golden era in mount development and choices now. The CN classifieds might provide you a cost effective way to go. Good luck. 

[lapsmith]

Yes, it is original with flat plate.  What makes the dovetail specific to to the original Nexstar?  If it is just length and hole locations, I could possibly make it fit as I have a small machine shop.

If it's an original Nexstar 5 (from the 5/8 and 5i/8i series around the year 2000), it has a flat plate for mounting instead of a dovetail. I have an original Nexstar 8 OTA myself. You'll need a retrofit dovetail specifically for the original 5/8. I got mine from eBay.

[lapsmith]

I anticipate being a visual only observer, and a lazy one at that.  I don't even like aligning the scope every time.  One question, how would one know if they got a poor mechanical example? I only have experience with the 5, but that may not be a good comparison.

 

Good info regarding the optical quality.  I have been mostly a solar system observer, but that is mainly because I could never find DSO's mainly because of where I lived.

 

I know my way around an oscilloscope and a milling machine so I'm not afraid to do the upgrade, unless I run into problems with the boards.  Hadn't thought that it might be an issue.  I will look seriously at the evolution mount as you are right, I don't want to limit myself or be disappointed in the future.  I will also look into Mlord's boards, that is something new to me.  Lots to think about, thanks.

I would say yes those original mounts were pretty good (but not NS GPS/CPC good)  - smoothness/backlash wise. This is anecdotal from the user base and use, but I haven't owned an original NS5/8. I believe that the motor gearbox used was a bit better quality on these earlier mounts.than on the later SEs (so a bit better backlash characteristics). I'm not sure any of this would make much of a difference to a visual user unless you happened to be comparing to a poor mechanical example of an SE (unfortunately not too uncommon).

 

The optical differences would really come down to the optical quality of each example. The C6s have generally been quite to very good with very few lemons. In addition to the aperture difference the coatings are better on the C6s (they're all XLT) and your much older C5 mirror would likely have degraded a bit so I think you'll easily notice the difference in brightness. So if you're a mixed (DSO and solar system) observer the C6 would be a significant upgrade, if however you have an optically really good C5 and you are primarily a solar system observer then perhaps it wouldn't make as much of a difference.

 

I think the direction for an upgrade will really depend on a) your budget and b) you're electrical/mechanical capabilities combined with a level of patience. 

 

So if the money isn't really an issue I personally would sell the NS5 and jump over an SE and right to a Evolution 6. While a bit more expensive the operation of that mount is better than the SE and I sense that you might find that really of value to you.

 

If however you have the expertise and patience to work with the electrics and you want to save some money. then the upgrade thread IMHO contains a great roadmap. I would also seriously consider (as SieglindeFestkochend has) to also add one of Mlord's homebrew DIY boards ... I might even consider doing one if I bought a new Evolution (adding GPS and some additional connectivity options). 

 

But don't underestimate the patience required to go through the board swap - if you get it working first time then fine but you could find that troubleshooting the upgrade sucking up a lot of time and possibly additional monies.

[mclewis1]

About backlash ... you'd know if it was a real problem. A bad example would have targets wandering around and sometimes out of the field of view, and good initial alignments would be tough to do. There is an anti-backlash training function in the hand controller to help compensate for much of this. Of the many many thousands of SEs out there only a very few users have posted here about bad examples.

 

For some reason from your original post I thought you might be particularly sensitive to it. Given your experience with the NS5 I really wouldn't worry about it on a new SE mount. If however you purchased a used one I might specifically ask about it. 

 

A 6SE with or without a StarSense would be a great setup, it's a step up from the old NS5, offering many additional years of enjoyment. For comparison the Evolution would be just a bit more "polished" hardware wise (bit smoother, additional load capacity, and some additional ease of use functions like built in WiFi, manual clutches, internal battery, etc.).There it's really comes down to budget and how much you might use and value those additional capabilities. The core hand controller functionality (initial alignment, goto, etc.) is however identical between the SE and Evolutions even though there are some additional menus on the Evolution to manage the extra hardware features.

[fullthrottle_man]

Yes, it is original with flat plate. What makes the dovetail specific to to the original Nexstar? If it is just length and hole locations, I could possibly make it fit as I have a small machine shop.

That's all you need then! The mount hole spacing is specific to the original Nexstar. It has 2 wide ones at the back and a single one up front. But a pretty easy quick fab is all it would take.

[lapsmith]

Simple mod then, thanks a bunch!

That's all you need then! The mount hole spacing is specific to the original Nexstar. It has 2 wide ones at the back and a single one up front. But a pretty easy quick fab is all it would take.