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LOSMANDY GEMINI 2 GOTO SYSTEM

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#1 Patrick

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Posted 31 January 2013 - 10:40 PM

Anyone out there using this goto system? I'm interested in hearing how well it works, if it has any quirks, and how accurate it is. How does it compare to the Celestron Nexstar firmware?

Thanks for any and all comments.

Patrick

#2 mich_al

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Posted 31 January 2013 - 11:12 PM

There is a pretty active yahoo group http://tech.groups.y...roup/Gemini-II/
I followed it while they where getting it all to work. It seemed like it was getting pretty well sorted out some months back. I haven't been tracking it lately.

#3 mega256

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Posted 31 January 2013 - 11:39 PM

Mine works GREAT...no problems
had it for the last18 mo....the software has been stable for at least the last 9mo+..
Realy like the touch screen,,,and I understand the new ones are shippng with the new HD motors,,,I bought one to replace and have a spare,,,very nice and better than any other they had...I use the web interface...

#4 Hilmi

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Posted 01 February 2013 - 01:27 AM

It now works as advertised. The developer is great as he has added two features at my request and the 3rd one "electronically assisted mount balancing" is on it's way. There is only one minor bug I know off that is pending a fix. After synchronizing dec axis guiding starts running away out of control. There is an easy workaround till the bug is fixed. Move slightly north then south after performing sync. Other than that I dont know of any bugs.

In short it works great.

#5 SMigol

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Posted 01 February 2013 - 01:48 AM

I use it on my mount and have learned a few quirks it has.

First, if you take the time to really polar align, then it will reward you with great gotos. There are some model building scripts that will greatly help with selecting the stars for you.

Second, the accuracy that you put into building the model will help. I personally will build a model of 3-5 stars per side of the meridian. This will hold for several nights and all I have to do when starting a new night is point to a star, slew to fix it, and then sync on the position. After that, it's good to go.

Also, if you take the time to park the scope between flips to shift the counter weight and then do the same effort to sync on a star on the new side, it will have the same level of precision that you'd want. The reason for this extra step is because I run with a little slack in the gears and the reposition of the weight helps keep them meshed.

These are the peculiarities of the system as I use it now. I'm sure that others have found solutions that work for them.

#6 EFT

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Posted 01 February 2013 - 10:43 AM

The Gemini 2 is a great improvement over the old, memorize the menu structure, system. The screen could definitely be bigger. I have no idea how someone would use the hand controller somewhere cold. It is still not as friendly as the Nexstar, but it has come a long ways since the Gemini 1 days and would make me consider a Losmandy mount where I probably wouldn't have in the past.

#7 Startraffic

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Posted 01 February 2013 - 02:22 PM

Patrick,
I have a G1 & G2. Both are very good systems. The G2 is a menu driven got that is still evolving. There are features that are not yet implemented but are being worked on by Rene' Gorlich. He's in Germany and is doing most of the software development. As it sits right now is a very functional Goto, Periodic Error Correction, Polar Alignment Correction (Cone Error), Polar Alignment Assist. The firmware is easily updated via a website download. A major PITA until you learn how to do it, & is VASTLY better than when it 1st came out. I moved mine for my G11 over to my HGM-200 about 4 months ago & it only required a mount type change & PEC. I keep dialing in the polar alignment (drift align) because the plan is for AP. I'm totally confident the mount & G2 can do that.

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#8 Patrick

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Posted 01 February 2013 - 11:27 PM

You guys aren't giving me the warm fuzzies here. :smirk: It sounds like the software is not fully developed yet and that makes me nervous. I really like the Nexstar software as it seems well designed, is stable and user friendly. Goto accuracy is spot on, too. Why should I switch to a system that is not full featured yet? It also sounds like aligning the mount (10 stars on each side?) would be a PITA. Am I missing something?

Patrick

#9 Charlie B

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Posted 02 February 2013 - 09:00 AM

I have both the CGEM and the G11. The CGEM is a good mount but, does not handle my heaviest OTA for astrophotography. The Gemini 2 and G11 do, with better guiding than the CGEM with lesser weight. The Gemini 2 software is being developed and has bugs, but no more than the CGEM has had. The best part of the Gemini is that it can use Ethernet and act as a pass through for any ASCOM compliant software using the native drivers. The CGEM can also, by using the virtual port, but requires a POTH hub and ASCOM drivers.

Charlie B

#10 Phil Cowell

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Posted 02 February 2013 - 09:01 AM

Patrick,
No you hit the nail on the head.
Phil

#11 Raginar

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Posted 02 February 2013 - 09:38 AM

I have both the CGEM and the G11. The CGEM is a good mount but, does not handle my heaviest OTA for astrophotography. The Gemini 2 and G11 do, with better guiding than the CGEM with lesser weight. The Gemini 2 software is being developed and has bugs, but no more than the CGEM has had. The best part of the Gemini is that it can use Ethernet and act as a pass through for any ASCOM compliant software using the native drivers. The CGEM can also, by using the virtual port, but requires a POTH hub and ASCOM drivers.

Charlie B


I agree with Charlie. Yes, Patrick, it's definitely more complicated than Nextar :).

#12 gdd

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Posted 02 February 2013 - 01:39 PM

It also sounds like aligning the mount (10 stars on each side?) would be a PITA. Am I missing something?



I'm not sure how sophisticated the CGEM alignment software is, but the G11/Gemini may be doing more. The more stars used for the modeling, the more accurate the model which not only includes cone error but flex in both the mount and the OTA.

Gale

#13 Patrick

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Posted 02 February 2013 - 10:54 PM

The CGEM uses up to 6 stars for alignment.

Here's the dilema...I'd like the tracking accuracy of the Losmandy with the user friendliness of the CGEM.

Patrick

#14 Peter in Reno

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Posted 02 February 2013 - 11:01 PM

If money was no object, A-P Mach1GTO would be nice. It's much easier to use than NexStar or Losmandy. Even though it does not have pointing models in the hand controller, the GoTo is excellent. The tracking is super smooth that I can guide up to 5 seconds guide exposure. The polar alignment for Mach1 is very easy and quick. After setting up the equipment, I then can get polar aligned within 15 minutes and can guide up to 30 minutes per sub with NB filters.

I was skeptical about Mach1 not having pointing models but it's not really needed once a good polar alignment is done. The Mach1 mount head weighs only 28lbs without counterweight shaft and has imaging carrying capacity of 45lbs.

Peter

#15 EFT

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Posted 02 February 2013 - 11:07 PM

The CGEM uses up to 6 stars for alignment.

Here's the dilema...I'd like the tracking accuracy of the Losmandy with the user friendliness of the CGEM.

Patrick


Tis always the problem. The consumer mount companies spend a lot of time making their control systems very user friendly while the high end mount companies spend more time on the mount mechanics. The Gemini 2 is probably the first higher end controller that has the chance to become more user friendly, it just may not be there yet.

#16 orlyandico

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Posted 02 February 2013 - 11:30 PM

heck.. i'd like the tracking accuracy of the Mach1 with the user friendliness of the CGEM :D

the 1-star align leaves something to be desired.. goto accuracy is completely dependent on how accurate the polar alignment is.

#17 Peter in Reno

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Posted 02 February 2013 - 11:39 PM

I use A-P Quick Drift Alignment (QDA) using cool Meridian Delay feature for polar alignment. This usually requires a right angle finder scope so that you align the finder scope to be orthogonal with the mount. Once orthogonal, the polar alignment is pretty dead accurate. With experience, it takes less than 15 minutes. Use Keypad Version 4.17 supplemental manual instead of Keypad Version 4.12 operating manual for QDA.

Sorry about hijacking this thread since this is about Losmandy mounts.

Peter

#18 orlyandico

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Posted 03 February 2013 - 12:00 AM

there's a G11 G2 in the classifieds for $2K!!! :tonofbricks:

that's the price of a new G11 non Gemini... a huge depreciation of almost 50%

that kind of says something about the G11... doesn't it?

#19 Hilmi

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Posted 03 February 2013 - 12:21 AM

Honestly, I did not find the Gemini II difficult to use. It could be easier to use, but I definitely would not classify it as difficult to use

#20 EFT

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Posted 03 February 2013 - 12:31 AM

there's a G11 G2 in the classifieds for $2K!!! :tonofbricks:

that's the price of a new G11 non Gemini... a huge depreciation of almost 50%

that kind of says something about the G11... doesn't it?


Of course that would appear to be no spring chicken of a G11. I don't think I have seen one quite that eggplant purple before. :grin:

#21 Peter in Reno

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Posted 03 February 2013 - 12:31 AM

It was wrong of me to say about Gemini II because I don't have first hand experience. I was referring to that I don't have to do any star alignments with Mach1 because all it takes is get good polar alignment and slew to one star to sync, that's it.

Peter

#22 pfile

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Posted 03 February 2013 - 12:50 AM

alright, i'm going to be as honest as i can here.

i like the mount and i actually like gemini-2 but it does have bugs. the firmware updates come slowly for various reasons. i use astrotortilla and never bother building any models. unfortunately back to back syncs near each other can confuse the gemini-2 and completely trash the pointing model.

mine won't respond to RA commands (from the ST-4 port) if PEC is loaded and running. it forgets the PEC curve all the time, meaning the check box for the PEC goes gray. i have to upload the curve again using PEMPro, which of course i had to purchase separately.

my particular copy has really awful PE. +/- 15 arcsec. and there are some fast spots on the worm that are not guidable.

one night, and i'm not sure whether it was my fault or not, for some reason the G2 kept tracking past it's limits and crashed my STT-8300M into the tripod. there was no damage to the camera, tripod or OTA, but apparently G2 kept supplying current to the RA motor and fried it. not completely, but after that the motor exhibited a really bad jitter. i had to swap the RA and DEC motors.

i knew that using this mount, especially at 2000mm, would be challenging. it does work, and i have been able to get some reasonable images, but i have to throw away many subs and the abovementioned bugs are annoying.

i have remedied the situation by getting a mach1gto. i plan on keeping the G11/G2 for wider-field setups.

#23 orlyandico

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Posted 03 February 2013 - 01:05 AM

pfile, that must be one of the worse stories i've heard.. i know hilmi also has some issues but seems he's fixed them (?) and his copy is performing well.

what i can say is the mach1 worked great out of the gate at 2350mm and an indifferent polar alignment and balance.

#24 Hilmi

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Posted 03 February 2013 - 01:23 AM

Let us remember that the question was about the Gemini II not the mount. I'm not fully satisfied with my mount, but the GII system has been very good, if not perfect. There is room for improvement and there are bugs but again in the interest of being fair:

-Firmware releases while not as fast as we would like them to be are faster than any I have seen with any device that I own. My phone, My advanced calculator, my LX200r mount my focus controller, non of these have been getting firmware updates as fast as the Gemini II.
-It is a relatively new system, most people who buy it are aware that it is work in progress and have done their homework in research.
-The only Gemini II specific bugs which I am aware off (Did I tell you I spend more time with the scope than I do with my wife, therefore I feel confident I have run across most of the bugs) are the PEC curve not retained bug and the bug resulting from synchronizing position that was mentioned by pfile.

People using the system on mounts that have no mechanical issues are very happy. Those of us not happy with their mounts mechanical performance are getting rather unrestful and are waiting for our next bonus to come along.

#25 pfile

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Posted 03 February 2013 - 01:39 AM

i only mentioned the G11 itself because it really needs PEC but the G2 problems prevent me from actually using it. if Patrick's mount is similar then it is relevant. to be honest aside from the losmandy mounts and the MI-250, i'm not sure what other mounts are really compatible with the G2. i had assumed Patrick would be looking at a G11 with the G2.

as i said i really do like the controller and the ascom driver for it and have made pretty good use of it. i just feel like the various bugs have cost me quite a bit of time, and clear skies around here are scarce. i need something that "just works".






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