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Hello,

I am not sure if this is the correct forum but I will ask anyway.? I have a G11, non-tucked in motors, Gemini 2 recently upgraded.? When I use the G11 with a short refractor I can set the limits with a fairly broad range, however when I put the TS Optics 130 on the mount, the limits have to be narrowed considerably to avoid a crash into the tripod.? Also, with either scope, the saddle can be quite close to the motors.? I could get the motors tucked in, which adds up in cost pretty fast, I could buy RA extensions to move the scope away from the motors and/or I could buy a pier extension to help clear the tripod.? Could someone please provide advice as to what may be the best first option???

I sure do appreciate the help.

Thank you,

Tom

I have a substantial 10” Newt on my G11G and the 12” pier extension allows me to image up to 55 minutes past the meridian. That being said, an 8” would have worked as well. I also have the RA extension and tucked motors.?

if you are considering a pier extension, slew your 130 vertical and measure how far below the top of the legs the lowest part of your imaging train hangs down. Then round up to the next pier extension length. That should get you to clear the legs.?

if you are hitting the motor prior to hitting the pier then perhaps the tucked motor upgrade would be worth it.?

I imagine you could save money by just tucking one motor? If it hits the DEC motor but not the RA motor maybe you could just tuck the DEC?

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RA extension probably won’t do much to increase your motor clearance because the DEC motor moves outward with the DEC axis. It might give you a little more room from the RA motor though.?

Thanks Ryan,

Yesterday I ordered an RA extension kit and a 12" pier extension.? I getting tired of monkeying around with it.? I will probably get the tucked motor upgrade next.

I hope that these two extensions will make it so that I don't lose so much imaging time around the meridian.? Is that a correct assumption?? It sounds like you have yours set up so that you don't have to wait before or after the meridian because you have such a wide limit range.??

Tom

Tom?

I believe you will be served well by the RA extension and Pier extension. I've attached some photos that will illustrate the increased mount rotation that you get by raising the OTA above the level of the leg attachment points. With any luck that will give you the additional range you need without needing to tuck the motors. I was initially worried that the increased height would add instability to the mount, but I have not noticed that at all. As someone who sets up and tears down almost daily, the RA extension also greatly increases the ease with which I do so.

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Hope these help reassure you in your decision and I wish you the best of luck.

Clear skies,

Ryan

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Thank you Ryan.

That is a nice rig and the clearance looks like heaven.? For the last two nights I had to monkey around with mine waiting for it to get far enough past the meridian so that it would move.? The HC kept displaying "Target Unreachable". It was making me crazy because it was so cold and I just wanted to go to bed.? I see palm trees in your photo...I start missing the palm trees right about now.

Do you have an Astrobin?? I would love to see images taken with that big black beauty.

Tom

Hey Tom,

Yes, I do, thanks for asking:

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I've pretty much completely rebuilt the scope from scratch which made it much more usable... most of my more recent images are with the scope, starting with this one:

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Let us know how it goes with the new extensions! Hope it solves your problems!

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Ryan

On Thu, Nov 7, 2024 at 11:02 AM, <Tjkallenbach@...> wrote:

Hello,

I am not sure if this is the correct forum but I will ask anyway.? I have a G11, non-tucked in motors, Gemini 2 recently upgraded.? When I use the G11 with a short refractor I can set the limits with a fairly broad range, however when I put the TS Optics 130 on the mount, the limits have to be narrowed considerably to avoid a crash into the tripod.? Also, with either scope, the saddle can be quite close to the motors.? I could get the motors tucked in, which adds up in cost pretty fast, I could buy RA extensions to move the scope away from the motors and/or I could buy a pier extension to help clear the tripod.? Could someone please provide advice as to what may be the best first option???

I sure do appreciate the help.

Thank you,

Tom

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Hi Tom,

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You will likely find that to get maximum limit range you will need to do all of the actual mount updates starting with tucked-in servo motors with spring loaded OPWs as well as the RAEXT.? These parts were designed to work together to overcome the mechanical interference limitations of the classic Losmandy straight-line motor drive configuration.? This means that unless you get these updates all done together you will not achieve the maximum RA and DEC freedom possible because the mount mechanically interferes with itself before you will have any OTA or imaging train mechanical interference.? Also depending on which tripod you use an 8" or 12" pier extension can improve the maximum limits available to your imaging system.??

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I just thought I’d mention a clearance issue with my own setup. I have a G11 on a permanent pier with the 4” pier height extension and the RA EXT right ascension axis extender.

Thus far the largest scope I’ve had on it is a carbon-fiber RC8. With this scope I get around 75 minutes of imaging on either side of the meridian. Ie., I can start with the scope 75 minutes E while imaging to the west, or image 75 minutes past the meridian when aiming towards the east.

If the RA EXT was about 2 inches ‘longer’ (or thicker), the saddle would be far enough from the mount that I could probably double the limits to nearly 150 minutes on either side of the meridian.

Years ago I used one of those Boller and Chivens 16 inch cassegrain scopes that had the Dec axis mounted at the end of a long RA shaft. No meridian flips were ever needed. I envy PlaneWave LA-350 mount users not having to do meridian flips, but not enough to drain my bank accounts. :-)

-Kevin

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On Fri, Nov 8, 2024 at 11:09 AM, Ryan Noonan wrote:

Tom?

I believe you will be served well by the RA extension and Pier extension. I've attached some photos that will illustrate the increased mount rotation that you get by raising the OTA above the level of the leg attachment points. With any luck that will give you the additional range you need without needing to tuck the motors. I was initially worried that the increased height would add instability to the mount, but I have not noticed that at all. As someone who sets up and tears down almost daily, the RA extension also greatly increases the ease with which I do so.

?

Hope these help reassure you in your decision and I wish you the best of luck.

Clear skies,

Ryan

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Hi Ryan,

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Another trick I have used and something you might consider if your mount is not payload limited is to add some counterweights on top of or behind the mirror end of the tube.? This allows you to push the tube forward in the rings and gain some clearance from the pier or tripod. The more you can push it out the more time you can gain before mechanical interference occurs.?

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Ah... Great idea Chip, thanks!

The rear end of my OTA got much lighter when I went to the Aurora Precision EQ cell but the drawback was that it hung much further down. That is a solid input.

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Cheers

Ryan

Thanks Chip,

I called Losmandy last week and they recommended the pier and RAEXT.? I will get the motors tucked in a few months.? The pier and RAEXT arrive tomorrow.? Apparently FedEX is also delivering a week of clouds and moon as well.? It looks like a pretty easy deal to add the ra extension so I will bring everything inside and set it up tomorrow.??

Right now my eastern limit is about 79 degrees.?

Tom

On Sun, Nov 10, 2024 at 11:51 AM, Ryan Noonan wrote:

Ah... Great idea Chip, thanks!

The rear end of my OTA got much lighter when I went to the Aurora Precision EQ cell but the drawback was that it hung much further down. That is a solid input.

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Cheers

Ryan

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Now that is a lovely mirror cell!? This counterweight tip works for large triplet refractors too where the focuser is a smaller lighter visually oriented model or the refractor is just a poorly designed front heavy monster and the typical commodity short tripod and mount designed for use with an SCT is maxed out for height and has you laying on the ground to observe.? This is funny to see IRL but not uncommon.? ?

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