开云体育

Hello All,

?

I am brand new to both AP as well as this forum. Really looking forward to getting to know both intimately.

?

Although I am new to AP, I have been shooting with long lenses for a while and I have good collection of them that I would like to put to good use.

?

I have a iOptron SGP which has so far served me well for WF imaging, but I am looking for something a bit more heavy duty. I am not at all interested in fully computerized goto mounts as I want to grow into the hobby organically and upgrade only when I am ready for it...I feel quite strongly about this.?

?

I have been offered a CG11 (or G11) locally, but not knowing a whole lot about these, I wanted to solicit opinions here. What I know so far:

?

My questions:

?

?

My backup option is the Orion Skyview Pro which is a whole lot cheaper, but also has a lower payload capacity.?

?

Would really appreciate any/all advice.?

?

Sincerely,

?

Avi

?

Hi and welcome.? The CG11 is a rebranded G11 but missing a few upgrades Losmandy made to the original CG11 mount. Parts are readily available and Losmandy can and does still offer updates for these mounts.?

?

That said there are some differences though almost everything can be retro fitted.? There are nice used G11 mounts that will have the later updates that are likely less mony and easier to update due to these small differences.? The CG11 can be updated with Losmandy Gemini 2 controller for GOTO and modern imaging tools.? So unless they are giving you the mount very cheap a Losmandy G11 or GM8 will likely be a better investment.??

?

As far as the Sky View Pro mounts go they are great manual mounts for small visual scopes.? I'm a huge fan and have owned and used several of these little gems.? I like the so much I have improved one over time adding nicer controls and CADing and CNCing an adapter to use the SVP on a tall wooden Oberwerk tripod.? This is a great setup I have used for visual work and as my traveling solar event mount.? I have a 2-axis drive, don't bother with the GOTO kit it is not quite smooth enough for imaging having a jerky stepper motor drive without fine enough steps to avoid this problem.?

?

--

?

?

?

Hi Avi, welcome to these forums. I’m not an expert on the subject but here’s my take on your queries.

?

The CG11 is indeed a “normal” G11 built by Losmandy for Celestron back in the day. These mounts are super reliable and easy to maintain and, the mechanics of the newest mounts are basically the same as the one you’re looking at. Only a few tweaks have been applied over the years, like spring loading the worms and such but, overall, it’s the same mount. This, to me, speaks volumes about the quality of these mounts and the original design. The beauty of all this is that, should you need help from the factory, the mount is fully serviceable by them and, to help things even more, there’s a healthy community of users that can also help. There are a few “official” repairers around the world (by official I mean people known to work on this mounts but not employed by Losmandy).

?

On to some of your questions. The CG11 has the 492 digital drive. The mount itself is a push-to. You just set it up, turn it on, disengage the clutches a bit and push your scope to where you want to look and then re-engage the clutches. Simple as that. Having said this, this particular drive system is geared more for visual use. It could be used for AP but it won’t be as easy as with a more modern mount with computerized goto and guiding.

?

If the package you’re looking at comes with the heavy duty tripod, that’s a nice bonus. That tripod is a tank and nothing short of an earthquake will move it. The polar scope will likely have the old reticle unless it was updated by the previous owner. However, the scope is not all that useful imo. It can give a good enough alignment for visual if that’s all you want and have a clear view of polaris, but for imaging other methods are quicker and more accurate.

?

I’d suggest heading over to Cloudynights’ classifieds and looking up G11s with the 492 drive. That should give you an idea how much to expect for a mount like this one.?

As for the tests you can do, I may not be qualified to say. But there aren’t many tests for the simple mechanics involved. Just make sure everything turns freely that should turn freely. That there’s not much play in the axes. That the grease is not dried and caked and, more importantly, that the drive system turns on and works properly

?

Finally, losmandy has a store website you can visit to check their prices for spare parts and upgrade kits. Just a bit of a warning, don’t dig too deeply on that site or you’ll empty your bank account trying to get as many goodies as you can. I speak from experience, the temptation can be overwhelming :)

?

good luck

?

jonathan

On Mon, Dec 9, 2024 at 11:31 AM, <avishekaiyar@...> wrote:

Hello All,

?

<<< SNIPPED >>>

?

?

My backup option is the Orion Skyview Pro which is a whole lot cheaper, but also has a lower payload capacity.?

?

Would really appreciate any/all advice.?

?

Sincerely,

?

Avi

?

I forgot not mention that the SVP has a very low payload and unless you have a small lightweight imaging optic and camera you will not be able to safely carry it on and SVP.? Think small refractor for visual use.??

?

--

?

?

?

Yeah...the SVP is not my top choice.?

?

If the Losmandy deal does not work out, I might just take a gradual approach and build up to heavy payload setups. I have lined up the Vixen Great Polaris as an alternative, but I understand that payload wise, it's not a whole lot higher than the Orion SVP.?

The PolarScope should have a small hole on one end for an illuminator that doesn't mean that they current owner may not have lost it.? One of the first things I do with those illuminators is spray paint the wire white so that if it falls on the ground I will see it.?

?

There have been three or four iterations of the stepper motors.? I am referring specifically to the stepper motors that go on the non-go-to g11.? The early vintage stepper motors often drew the annoyance of users because at very high magnifications you could see a slight jitter from the stepper motor movement.?

?

The later stepper motors don't do this but the ones on your celestron vintage mount surely do.? They are pretty easy to swap out but it is an expense.? I would make sure to knock $200 off the price to cover the new motors.??

?

The go-to versions have servo motors and are completely different animals.??

?

I have had my g11 for 20 years now It is one of the most reliable items I have ever purchased.? ?I use it with encoders and Argo Navis.

?

Greg N

On Mon, Dec 9, 2024 at 02:31 PM, <avishekaiyar@...> wrote:

Hello All,

?

I am brand new to both AP as well as this forum. Really looking forward to getting to know both intimately.

?

Although I am new to AP, I have been shooting with long lenses for a while and I have good collection of them that I would like to put to good use.

?

I have a iOptron SGP which has so far served me well for WF imaging, but I am looking for something a bit more heavy duty. I am not at all interested in fully computerized goto mounts as I want to grow into the hobby organically and upgrade only when I am ready for it...I feel quite strongly about this.?

?

I have been offered a CG11 (or G11) locally, but not knowing a whole lot about these, I wanted to solicit opinions here. What I know so far:

?

• I think it's an early Losmandy non-goto model when they were making mounts under the Celestron brand? It comes with the Celestron Digital Drive system. I am waiting to get the serial number.?
• Seems like the full setup with tripod, polarscpe etc. Checking to see if the polar scope is illuminated or not.?

My questions:

?

• is how risky is this purchase given the age of this mount and potentially availability of spare parts in case something goes wrong? I have read only good things about the reliability of Losmandy mounts, but still.
• Are these still supported by Losmandy and if something goes wrong, how much money am I looking at dropping in getting the mount fixed??
• What is a "good" price for the mount??
• And finally...if I do decide to purchase this mount, what kind of tests should I look to do befor getting it??

?

My backup option is the Orion Skyview Pro which is a whole lot cheaper, but also has a lower payload capacity.?

?

Would really appreciate any/all advice.?

Hi Avi,

?

I bought a 1997 era G11 which had no working drive system and was able to convert it to a high-performance AP mount using the OnStep system. Now it is fully controllable with ASCOM and guides with excellent precision. Just beware that this is a project in itself, and you will need to have some specially machined brackets made to do the conversion. I think the guy who did the conversion for me may still be doing them, so please send me a PM if you are interested in this route. I would pay no more than $500 for the old mount as the conversion is a lot more than that. But I can vouch that the final outcome was better than expected. You really are going to need a fully controllable GoTo mount for decent AP results as the today's software needs to do slewing and platesolving to get precisely on target. Everyone also uses PHD2 or some other guiding software to adjust tracking to compensate for seeing and mechanical fluctuations. Just beware that the base plates from that era were a different design the present and the newest Gemini 2 system may not work without a major retrofit. Losmandy will most likely want you to buy a new mount over revamping a very old mount like you mentioned. But the G11s really do handle high payloads up to 60 pounds, not including counterweights.?

?

If you're not interested in doing OnStep or a retrofit, you may want to look for used G11s with at least the Gemini 1 system. Most of these mounts can be serviced or rebuilt with a bit of mechanical aptitude and some elbow grease, and the bearings and other working parts are still available at HGM. It all depends on what your budget is and how much time you are willing to invest.?

?

Good luck.

?

John

?

?

--

__________________________________________________________________________________________________________________________________________________________________________

Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user

Hi John?

?

Thanks for the advice. I am definitely interested in the OnStep conversion but not right now as I want to start with the very basics first and then upgrade when I am ready for it.?

?

I can't quite figure out how to send a PM on this platform..will try again from my laptop .

?

Avi?

On Tue, Dec 10, 2024 at 07:21 AM, <avishekaiyar@...> wrote:

Hi John?

?

Thanks for the advice. I am definitely interested in the OnStep conversion but not right now as I want to start with the very basics first and then upgrade when I am ready for it.?

?

I can't quite figure out how to send a PM on this platform..will try again from my laptop .

?

Avi?

?

When you reply look for the header labels "To" with the word "Group" in it.? If you scroll over it you can choose Group, Sender or Moderator.? Pick Sender and off you go.??

--

?

?

?

Avi,

?

Some of what I'll say will be redundant, I'm sure.

?

I started out with modern gear (dating back to the days of AC synchronous motors for the RA and star hopping, with manual eyeball and finger guiding) when I bought a used G11 in 2006.

It was a huge upgrade compared to my earlier gear. The only change I made was to swap out the earlier stainless steel worms with the high precision brass ones.

This was before Losmandy introduced the one-block worm mountings. I've never felt the need to do that - I routinely image at focal lengths of 10 to 1500mm, guided, of course.

?

The only mounts I would consider, from the standpoint of a pure user, due to the support and spare parts situation, are Losmandy, Astro-Physics, or Planewave; listed in order of increasing cost.

Orion is out of business so I wouldn't touch the Skyview Pro unless you're looking for a project. Terran Industries makes an OnStep conversion kit for it, I believe, for under $175, motors and all.

?

One correction to someone else's statement: You can autoguide with the Model 492 drive as-is. You don't have to have Gemini or OnStep to do that.

?

At the lower left of the control box/panel of the 492 there is a modular phone jack (6 position, 6 contact or 6P6C) labelled "CCD".

That labeling is a relic of the early days when only SBIG made guiding and imaging cameras.

?

In fact, that receptacle is a purely electrical (as opposed to a serial link) connection intended for auto guiding via what is know as an ST4 interface.

Electrically it is the same as the handbox receptacle next to it.

?

I repeat: It's a simple electrical interface, not a software message port like an RS232. In fact, if you plug an RS232 link into it you may blow something because RS232 voltage levels (to allow 100 foot or longer connections) are in the range of 10 to 15 volts. It's an easy mistake to make since the industry tries to use modular jacks for everything - ST4, handboxes (simple and complex), motors, serial links, you name.

?

They make plenty of inexpensive autoguiding cameras that have USB ports to connect to a laptop running the (free) guiding software. These same guide cameras will have a matching ST4 receptacle and will come with a cable to connect the guide camera to the "CCD" receptacle on the drive.? Connect the USB on the guider to a USB port on the laptop and connect the guider ST4 to the mount ST4. Simple as pie.

?

I used the 492 for years until going the OnStep route, partly because it was fun, partly because I was trying to image fainter objects and was getting older, and partly because if there was a parts problem I could work around it myself.

?

Mark Christensen

?

Dear Mark,

?

Thanks so much for all the valuable details.?

?

The more I am getting opinions, the more I am getting swayed towards the CG11. I have ruled the Orion SVP out already. For me it's now down to the CG11 or a Celestron Advanced GT that someone on Cloudynights has kindly offered to sell.?

?

John above mentioned $500 as a good price, but I that will likely not happen....The mount comes with the original heavy duty tripod, polarscope etc.....the only factor is the age.?

?

For the ST4 port, I am assuming this is what you are referring to? I have a ZWO guide camera and an SVBony guidescope, so I guess I am all set for autoguiding with the ASiAir.?

?

But the seller is also including the hand controller which also has an ST4 cable coming out of it.....which I am assuming plugs into the "CCD" port on the 492 panel? so where do I plug in the guide camera??

?

Hi George,

?

This is very reassuring!

?

Avi

On Wed, Dec 11, 2024 at 12:05 PM, Mark Christensen wrote:

Terran Industries makes an OnStep conversion kit for it, I believe, for under $175, motors and all.

?

Some caution is advised thinking the cheap OnStep kits on AliExpress will work with the old G11s. The motors are underpowered are not the same as the OnStep forum recommends. And AliExpress does not take items back without a major struggle.? ?You can get some more advice posting a question on their groups.io forum where G11 conversions have been discussed quite a few time. The older G11s also were not built for modern astrophotography and you may not get the necessary guiding performance without some mechanical revamping. Whatever control unit you choose, make sure it is ASCOM compatible. ST4 autoguiding is starting to go away and the latest cameras are omitting the ST4 port. OnStep allows direct drive guiding with PHD2 and all the communications necessary for ASCOM control. There is some difference between getting the mount operational and futureproofing for continued years of use.?

?

John

_____________________________________________________________________________________________________________________________________________________________________________

Losmandy G11G2 on pier; refurbed Losmandy G11 with OnStep controller; SkyShed design roll-off observatory; ZWO ASI2600MM-P; ZWO ASI071MC; Sky-Watcher Esprit 100 ED with field flattener; Celestron C925 Edge HD with 0.7XFR, William Optics Zenithstar 61 APO; PHD2, NINA, Sequence Generator Pro and PixInsight user

Terran Industries is here in the Chicago area, and you buy stuff directly from them, not AliExpress.

?

Mark C

Get a straight thru Y-splitter for the RJ12 (6P6C) with male on one end and dual female on the other:

?

?

Or, if needed to clear the IN power jack, a single female to dual female and make up a little cable, making sure to get the orientation of the wires right in the plugs.

?

Available at retailers, Amazon, Ebay, or ShowMeCables.

?

Just make sure it has 6 contacts, not 4. That's an RJ11 (6P4C), a common source of confusion.

?

Enjoy,

?

Mark C

?

Hi John?

?

Good to know about guiding performance with the old G11s...I didn't know that. Future proofing is a big part of why I am interested in the Losmandy...if I cannot get that or if I need to spend considerable additional dollars to make it future proof, I will have to rethink.

?

I have no intention of attempting OnStep or like conversions...at least not the next year or so.?

?

For now I am just happy if I can get guiding using the Asiair, which is what I have.?

On Thu, Dec 12, 2024 at 07:33 AM, <avishekaiyar@...> wrote:

Hi John?

?

Good to know about guiding performance with the old G11s...I didn't know that. Future proofing is a big part of why I am interested in the Losmandy...if I cannot get that or if I need to spend considerable additional dollars to make it future proof, I will have to rethink.

?

I have no intention of attempting OnStep or like conversions...at least not the next year or so.?

?

For now I am just happy if I can get guiding using the Asiair, which is what I have.?

?

The ASIAIR cannot be used to directly autoguide the #492 digital drive.? The #492 can be used with an ST4 port autoguider but the ASIAIR cannot connect directly to a #492 for autoguiding as the #492 is not a GOTO mount and lacks a USB port.? This is not to say you cannot use an ASIAIR to control your imaging camera and collect images while the #492 powers the mount and takes corrections from the guide camera ST4 port.? I have not done it but you may be able to use the ASIAIR to initialize the guide camera with guiding pulses sent to the #492 ccd/hc port to guide the mount.? ? ??

?

--

?

?

?

Hi Chip,?

?

On the iOptron SGP (non-goto as well), there is a similar ST4 port. My assumption was that I would hookup the ST4 to the guide camera (ZWO). Then connect the camera to the ASiAir using the USB port. So the ASIAir does not directly connect with the mount, but does so via the guide camera.?

?

Simultaneously, I also connect my main camera (Nikon Z7ii) to the ASiAir to collect image stacks.?

?

I am assuming/hoping I can do the same thing with the CG11......no??

?