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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... new

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[Re: t.r.]
#2977920 - 03/11/09 02:37 PM Attachment (135 downloads)

Not yet - I would own it if there was.

Here is what the top of the tripod looks like:

Edited by Lane (03/11/09 02:48 PM)

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t.r.
Post Laureate

Reged: 02/14/08

Loc: Upstate NY

Re: The ultimate CGEM topic ... new

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[Re: Lane]
#2977993 - 03/11/09 03:11 PM

Lane, thanks for the pic...did you by chance also have a CG5 to compare with? I always felt the 2" tripod on the CG5 was the weak link for stability and if its the same as the CGEM with a heavier head????? Not sure how much better the CGEM would be for 40#'s ya know?

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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... new

new

[Re: t.r.]
#2978073 - 03/11/09 03:54 PM

I dont' own one but I have seen the top of the cg-5 tripod and it has the wider hole like most of the other scopes do. The cgem is the first one I have seen with that small mounting hole. In terms of stability the cg-5 is about equal to the sirius (heq5). The older sirius has 1.75" legs and is a little less stable, but the new one comes with 2" legs and seems to be the equal of the cg-5. But neither of these mounts come close to the atlas or the cgem in terms of stability. I think it is simply a matter of the more massive size of the mount heads. The atlas at 36 lbs and the cgem at 40 lbs with counterweight bars. The difference is like night and day in my opinion. To me the sirius and cg-5 really match up well with an 8" sct, but the cgem is well matched with the 11" sct.

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jrbarnett
Eyepiece Hooligan

Reged: 02/28/06

Loc: Petaluma, CA

Re: The ultimate CGEM topic ... new

new

[Re: Lane]
#2978117 - 03/11/09 04:20 PM

Is the CGEM perhaps the same as an Atlas in this regard? It certainly looks the same. If so, wouldn't the Atlas pier extension work? Orion sells them. I use one on my Atlas and if I switch to a CGEM (once it gets a bit more mature) in order to move over to Nexstar from Synscan, I assume the CGEM will fit not only my pier extension but also my Atlas-adapted Antares 48" pier.

I sure hope so.

Regards,

Jim

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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... new

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[Re: jrbarnett]
#2978158 - 03/11/09 04:36 PM

I have never seen the top of the atlas tripod but I thought it was the same as the sirius. Look at the measurement of the CGEM center hole in that picture above it is a little less than 1 and 1/4" in diameter. I think the atlas mount has a hole that is at least 3/4" wider than that.

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Charlie Hein
Postmaster

Reged: 11/02/03

Loc: 26.06.08N, +80.23.08W

Re: The ultimate CGEM topic ... new

new

[Re: t.r.]
#2978412 - 03/11/09 06:38 PM

Quote:

Is there a pier extension available for the CGEM then(I should say half-pillar)?

The one for the Atlas should work just fine...

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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... new

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[Re: Charlie Hein]
#2978554 - 03/11/09 08:11 PM

Quote:

Quote:

Is there a pier extension available for the CGEM then(I should say half-pillar)?

The one for the Atlas should work just fine...

You know this for a fact?

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Charlie Hein
Postmaster

Reged: 11/02/03

Loc: 26.06.08N, +80.23.08W

Re: The ultimate CGEM topic ... new

new

[Re: Lane]
#2978588 - 03/11/09 08:37 PM

Quote:

Quote:

Quote:

Is there a pier extension available for the CGEM then(I should say half-pillar)?

The one for the Atlas should work just fine...

You know this for a fact?

Not from personal experience, although I got a very good look at the CGEM recently at the WSP. The CGEM and Atlas are remarkably similar mounts. I didn't measure the tripod where it meets up with the base of the mount, but my "eyeball" estimation says the tripod is identical to the one that came with my Atlas - if it's off it can't be by very much at all. Perhaps someone can measure their CGEM tripod and give you the dimensions and the screw pitch of the bolt that holds the mount to the tripod.

You might want to call Orion and put the question to them. Since they also sell Celestron they most likely can give you a definitive answer.

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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... new

new

[Re: Charlie Hein]
#2978606 - 03/11/09 08:50 PM

The picture you see at the top of this page is a picture of the tripod head from the cgem. The screw is 12mm, which is the same one used on the sirius mount and probably the Atlas. But I was under the impression that the hole surrounding that screw was much larger on the atlas. It is only about 1 3/16" on the cgem tripod as you can see in the picture. If that hole is not the same width and depth then I don't see how an atlas pier could work. If they are the same then I am going to buy that pier.

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Alan S
professor emeritus

Reged: 10/27/07

Re: The ultimate CGEM topic ... new

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[Re: Lane]
#2978950 - 03/12/09 12:45 AM

I have a CGEM- note in the picture above that there are actually two holes for the mount head...there is the deep hole which the M12 threaded rod comes up through, and there is a wider hole (just over 2.5 inches in diameter) that is only about 1/8 inch deep. The mount head actually fits into both of these.

I have never seen the base of an Atlas.
Alan

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Skylook123
Postmaster

Reged: 04/30/05

Loc: Tucson, AZ

Re: The ultimate CGEM topic ... new

new

[Re: Alan S]
#2978975 - 03/12/09 01:22 AM

The picture also shows the pin in the as-shipped between-legs position, which can be a safety hazard. Atlases and EQ6s are also shipped this way.

Over the years, with the Atlas, many folks will move the pin to the hole on the opposite side and use that leg as the North leg. The mount and tripod is much less likely to tip over with the pin over a leg rather than as delivered.

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waassaabee
Post Laureate

Reged: 11/26/07

Loc: Central California Coast

Re: The ultimate CGEM topic ... new

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[Re: Skylook123]
#2979200 - 03/12/09 08:01 AM

Quote:

The picture also shows the pin in the as-shipped between-legs position, which can be a safety hazard. Atlases and EQ6s are also shipped this way.

Over the years, with the Atlas, many folks will move the pin to the hole on the opposite side and use that leg as the North leg. The mount and tripod is much less likely to tip over with the pin over a leg rather than as delivered.

I also did that with my CG5 to make Polar alignment easier. I don't extend the legs all the way out while imaging, and straddling the leg was a pain to see through the polar finder and adjust the mount. Moving the pin over the leg gave me room to kneel between the legs and get to the adjustment screws easier.

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Blixx
professor emeritus

Reged: 12/02/07

Loc: CO. Aurora, USA

Re: The ultimate CGEM topic ... new

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[Re: waassaabee]
#2979841 - 03/12/09 03:11 PM

I just got an email from Celestron. For anyone how is interested, The mount has the ability to choose the scope orirntation. You can choose to use a dual scope setup. It is in the scope setup part of the HC. This is a bonus for those of us how want to try a side by side setup, and not have to change a lot of stuff and save some $$$. I have also found a good but cheap SBS rail with the Losmandy plate and the shoes for vixen dovetails. I found it on scopestuff(I hope I can say this). The #is TVDS. I am going to try it out and see how it works as soon as I get the mount. I talked to Jim and he said that they will have another setup the same way but with a longer mounting plate in a couple of months. This will make it easer to mount larger scopes side by side.
I just thought that some of you guys and gals might like to know.
Dan

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mclewis1
Thread Killer

Reged: 02/25/06

Loc: New Brunswick, Canada

Re: The ultimate CGEM topic ... new

new

[Re: Blixx]
#2979902 - 03/12/09 03:48 PM

Dan,

Interesting that Celestron would point out the OTA orientation as something of interest for the CGEM. That feature is important for CGE owners, but as far as I know not for CGEM or the CG-5, those mounts don't care about the orientation of the DEC axis.

You could setup a side by side config on your CG-5 tonight ... the firmware doesn't care (and yes you do have to ignore the index marks).

I generally like Jim's stuff, that smaller SBS setup he has is a nice lower cost option but you really have to watch those small vixen compatible saddles. They are fine if you have longer rails on your scope(s) but they don't offer much fore and aft movement with short rails (makes balancing a bit tricky) and the bolt ends tend to mark up your rails.

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Alph
Pooh-Bah

Reged: 11/23/06

Loc: Melmac

Re: The ultimate CGEM topic ... [Re: mclewis1]
#2979916 - 03/12/09 03:56 PM

Quote:

Interesting that Celestron would point out the OTA orientation as something of interest for the CGEM.

I find that very typical of the Celestron customer service. They are not very knowledgeable and one has to take their advice with a grain of salt.

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Blixx
professor emeritus

Reged: 12/02/07

Loc: CO. Aurora, USA

Re: The ultimate CGEM topic ... [Re: Alph]
#2980003 - 03/12/09 04:52 PM

So if it doesn't have the abelity of knowing where the mount is(in relation to the gears inside) why does Celestron say that you can use that option?
Dan

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Lane
Post Laureate

Reged: 11/19/07

Loc: Frisco, Texas

Re: The ultimate CGEM topic ... [Re: Blixx]
#2980018 - 03/12/09 05:05 PM

That feature is mentioned in the user guide. My guess is that by turning on this feature you can still use the same index marks when performing initial setup with a side by side plate. You are telling the mount that the scopes are actually perpendicular to the index marks. If you choose not to use this feature then I think it would still work but you would have to ignore the index marks and point the scopes north when doing the setup.

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rmollise
Postmaster

Reged: 07/06/07

Re: The ultimate CGEM topic ... [Re: mclewis1]
#2980095 - 03/12/09 05:57 PM

Quote:

Dan,

Interesting that Celestron would point out the OTA orientation as something of interest for the CGEM. That feature is important for CGE owners, but as far as I know not for CGEM or the CG-5, those mounts don't care about the orientation of the DEC axis.

You could setup a side by side config on your CG-5 tonight ... the firmware doesn't care (and yes you do have to ignore the index marks).

You really don't want to ignore the index marks. These mounts want you to start from the same position each time. Using the side-by-side feature means you don't have to move/make additional marks.

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Blixx
professor emeritus

Reged: 12/02/07

Loc: CO. Aurora, USA

Re: The ultimate CGEM topic ... [Re: rmollise]
#2980113 - 03/12/09 06:04 PM

I just got another email from Celestron. All they will say is look on PG. 27 of the users manual. So on PG. 27 it says that you have to tell the mount which direction the scopes are facing(east or west). So, I guess I will have to see if it works when I get the mount.
Dan

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mclewis1
Thread Killer

Reged: 02/25/06

Loc: New Brunswick, Canada

Re: The ultimate CGEM topic ... [Re: Lane]
#2980150 - 03/12/09 06:21 PM

Did a quick check indoors on my CG-5's behaviour with and without the side by side bar used.

My CG-5 has the new 4.15 HC firmware, and the original 5.04 MC firmware. I have an ADM Vixen side by side bar and a C6 to mount on it.

1) C6 in the stock CG5 saddle, Index marks aligned, scope pointed North, OTA Orientation is Normal. Time, date, Solar Systems alignment, Venus ... scope points roughly to where Venus currently is.

2) Add the side by side bar, turn the DEC axis 90°, DEC index mark not aligned, Scope pointed North, OTA Orientation is Normal. Time, date, Solar Systems alignment, Venus ... scope points roughly to where Venus currently is.

3) Side by side bar, don't turn the DEC axis 90°, both Index marks are aligned, Scope pointed East, OTA Orientation is Normal. Time, date, Solar Systems alignment, Venus ... scope does not point to where Venus currently is ... off by 90°.

4) Side by side bar, don't turn the DEC axis 90°, both Index marks are aligned, Scope pointed East, OTA Orientation is East. Time, date, Solar Systems alignment, Venus ... scope points to where Venus currently is.

The assumption is that this is also exactly how the CGEM will behave.

Quote:

That feature is mentioned in the user guide. My guess is that by turning on this feature you can still use the same index marks when performing initial setup with a side by side plate. You are telling the mount that the scopes are actually perpendicular to the index marks. If you choose not to use this feature then I think it would still work but you would have to ignore the index marks and point the scopes north when doing the setup.

Lane,

You're correct, that is how the mount behaves with the OTA Orientation function set to East or West (depending on how the DEC axis is oriented).

Dan,

I'm not sure why the folks on the phones would say that but I stand by my earlier statement with the addendum that Lane has added. The OTA Orientation function allows you to keep using the index marks but on the CG5 and CGEM if you ignore the index marks you can ignore the OTA Orientation function and the CG5 or CGEM will work just fine with a side by side saddle configuration.

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