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CPC mount to replace Nexstar 8 se mount?

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#1 tim57064

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Posted 15 July 2013 - 12:39 PM

Hello,I thought this was a good place to make the inquiry on the subject matter. I have been thinking about replacing My Nexstar 8SE mount with a CPC mount and was wondering if it would be worth it? The stability should be better for visual,seeing it is a dual fork arm yet would the mount then be better for short exposure imaging also? I am sure someone here has used it for imaging and I am curious as to what exposure lengths/times have been used successfully? I would appreciate any help. I must say I would be using my Canon T4I as an imaging platform. I have used the Canon a couple of times on my Nexstar mount with limited success.I do have a CG5 Advanced mount yet I would be strictly using that for my 6" refractor til' I can afford a more stable mount for it. I want to thank you all ahead of time. Again thoughts on the CPC mount for the Nexstar 8SE replacement.
I also want to add that I have the opportunity to purchase a Nexstar8 GPS fork mount for $495.00 plus shipping and was wondering if you think it would be worth it,if in good condition.

#2 KerryR

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Posted 15 July 2013 - 01:25 PM

Will the 8SE ota easily move to the fork mounts? They may not be directly interchangeable.

Seems like you should be able to get a good start on imaging just by piggybacking your camera on your existing scope and mount in EQ mode.

#3 tim57064

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Posted 15 July 2013 - 01:32 PM

Kerry,First,thank you for your reply. I like to have a couple of scopes set up at the same time for comparing the views and my equatorial mount is primarily for my 6" Refractor. If I had to drill and tap new holes,that would not be a problem for me. It would be nice though if you could just interchange. I did this with the Meade 10" that was originally on an LX6 mount when going to the LX200 mount. Although they are both dual fork arms.

#4 St Pete Keith

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Posted 16 July 2013 - 02:59 AM

Be sure that the mount and ota are compatable. With the 1100, the cpc mount requires the rear cell of the ota to have the beveled cell and not the square edged version. I would ask for a picture of the Sellers original ota for comparison.

If it was me, dollar for dollar, With AP in the mix, I would go for another CG5. I simply love mine and would be a straight swap.

#5 cn register 5

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Posted 16 July 2013 - 10:41 AM

I don't understand this talk of replacing OTAs on the CPC.

The CPC is a double arm fork mount with the OTA permanently mounted.

If you are thinking of buying a mount where someone has removed the OTA then you may have a challenge.
First you don't know what is left.
Second, and critically, the mount relies on the OTA being mounted orthogonally to the Dec axis. If you don't get this right then the scope will never do slews accurately. You are looking at getting this correct to within a few arc minutes.

Chris

#6 tim57064

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Posted 17 July 2013 - 11:34 AM

First I want to thank You for your response.
Okay you say you don't understand the talk of replacing the ota's on the CPC?
I would like to have a more stable mount and am thinking about the CPC or the Nexstar GPS mount since they are double fork arm mounts.
I was thinking that there may be a number of them out there where individuals switched to equatorial mounts and would give me a chance to purchase one for a reasonable price.
You say permanently mounted?
Permanent to me means you cannot remove.
Why would I have a challenge?
Why do you say "you don't know what is left"? Please explain.
I am aware that the scope needs to be aligned in the mount so as to track properly. This does not to me seem to be problematic.
Have you made an attempt at doing this? I would like to know if you have as this is why I have asked if it can be accomplished. I have changed out/upgraded fork arm mounts with other scopes and have been successful so do not think it would be hard to do again. Was hopeful that I might find someone here that has done this with the Nexstar 8SE to the CPC or the Nexstar GPS. Thanks

#7 cn register 5

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Posted 17 July 2013 - 05:59 PM

There's nothing more I can say, do what you want.

Chris

#8 Geo.

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Posted 18 July 2013 - 09:26 PM

The machining of the rear cell is quite different on the SE and CPC OTAs. It can be done but it's not a wrench and screw driver job. Orthogonal alignment can and has been done by users. There are destructions on the web. I use three laser levels and it seems to come out right.

#9 tim57064

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Posted 19 July 2013 - 09:45 AM

Okay,After considering all that has been said,which I truly appreciate everyone's comments and suggestions,I have decided to hold off on the CPC or Nexstar GPS as a replacement.
I am now considering a Meade LXD-75 Mount.So I guess I should go to the mount forum and look for info/help there. Thank You all very much.

#10 mclewis1

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Posted 19 July 2013 - 10:42 AM

Tim,

Since you are somewhat used to the NexStar firmware I would suggest taking a good look at the AVX vs. that LXD mount. The LXDs also seem to have had some really nasty QA issues over the past few years (from comments in the Meade "The Plot Thickens ... " thread).

#11 tim57064

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Posted 19 July 2013 - 11:15 AM

Mark, I appreciatte your input here. I had totally forgot about the AVX mount and may consider it.Now I am not sure as I may even consider a CGEM as I see they are getting more reasonable in price for used also. The payload capacity should be better too. AVX is closer to the CG5 Advanced ,as far as the payload, correct?






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