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Losmandy Mount GM8 + Other Goto's

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#1 bdg

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Posted 03 November 2013 - 08:10 PM

Hello, after first hand experiencing the poor quality control and not so good customer service experience of overseas mounts, I'm thinking about sinking big $$ on Losmandy GM8 for AP+Visual, however I'm disappointed that Losmandy doesn't come with default GOTO controller and there an option to upgrade to expensive Gemini GOTO.

Is there any option to get the mechanically sound Losmandy GM8 and use someother GOTO controller or use a laptop woth EQMOD like program to provide GOTO functions.

What are my options with Losmandy+ computerized setup.

#2 pfile

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Posted 03 November 2013 - 08:35 PM

as far as i know only sitech is a viable alternative to gemini-ii for losmandy mounts.

imho, and it is just one man's opinion... i would stay away from the g2.

rob

#3 bdg

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Posted 03 November 2013 - 08:50 PM

as far as i know only sitech is a viable alternative to gemini-ii for losmandy mounts.

imho, and it is just one man's opinion... i would stay away from the g2.

rob


Sitech? another name to add into my Database :foreheadslap:

what is G2 ?

#4 terry59

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Posted 03 November 2013 - 08:59 PM

I also have a GM-8 in addition to my Sirius. My experience has been positive but what pfile says about Gemini or Sitech is true.

#5 gdd

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Posted 03 November 2013 - 09:36 PM

what is G2 ?



Short for Gemini-2, the new version with a graphical display. When it was first introduced many of the features were missing or not working correctly. Since then the issues have been resolved.

I have the G11 with Gemini-2 and find it easy to use, but I do not make much use of the advanced features. A lot of people have trouble with modelling (requires alignment with several stars) for accurate GOTO's. But I find it simpler to just align on a couple of stars, then do a sync to a nearby bright star followed by a goto the target. Since you will probably be doing short focal lengths with a GM8 the goto accuracy requirements can be relaxed IMO.

Gale

#6 pfile

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Posted 03 November 2013 - 10:44 PM

on the version of firmware i last used, even with no models built up, repeated syncs near one another (such as will happen when running astrotortilla) would create a corrupt model, causing the next goto to go off into hyperspace. completely frustrating when imaging and trying to home in on your target.

i am not sure if this bug was fixed.

furthermore mine loses PEC all the time and judging from the traffic on the mailing list, that's still happening. serious detour going on right now with (erroneous) claims that a cold start erases the PEC because the worm position is lost on a cold start (not true.)

also with my G2 when PEC was active, the G2 would not accept guide inputs. this also has happened to other people, was reported multiple times, but no fix because apparently rene simply can't reproduce the problems.

i just don't get the sense bugs are taken seriously. also the release process for the gemini-2 firmware is extremely iffy - no changelogs are ever provided, no one knows what bugs have been fixed, and which have been ignored.

new features come in and are incomplete, like the counterweight balance calculator. the hand controller complains that the current to the motors is too high in a normal slew (with the cryptic message "Heavy Duty T.R."), and the webserver page needed to adjust the tolerances was missing from the build - apparently was simply forgotten. little or no QA for firmware releases.

rob

#7 pfile

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Posted 03 November 2013 - 10:50 PM

having said all that, there are apparently a lot of satisfied G2 customers. i can only guess that they use the computer in such a way that never triggers these bugs, and so are blissfully unaware of them.

rob

#8 orlyandico

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Posted 03 November 2013 - 10:55 PM

SiTech requires a computer all the time - no quick grab and go for you.

If you can get a Vixen SkySensor 2000 it can be configured to drive a Losmandy mount. A very robust GoTo controller, but it is long discontinued and so if you can find one, spares and repairs will be problematic.

Then there are the German stepper controllers - the Littlefoot, Boxdoerfer, and FS2. As far as I know all of them do one-star aligns, so require very precise polar alignment and cannot compensate for mount non-orthogonality.

If you are handy with electronics DIY there is AstroEQ which is an Arduino-based GoTo controller that is compatible with Synscan handsets and EQMOD.

#9 Bob Gillette

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Posted 03 November 2013 - 11:13 PM

And try finding a coherent manual for G2. Neither Losmandy nor the G2 developer care enough to provide one, leaving the field to earnest amateurs.

#10 terry59

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Posted 03 November 2013 - 11:56 PM

And the bashing begins. Sorry I participated here :step:

#11 pfile

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Posted 04 November 2013 - 12:01 AM

terry, i would not call that bashing. look, some people are happy with the G2, some are not, for a variety of reasons.

i think people should be able to make an informed choice.

rob

#12 terry59

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Posted 04 November 2013 - 12:06 AM

Rob,

I agree and support what you are saying about providing information to help people make informed decisions. My time with my GM-8 hasn't been trouble free either. I think I'm just tired of urinary olympiads that occur on here and may be overly sensitive. Dunno. Anyway, I've given my view.

#13 bdg

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Posted 04 November 2013 - 12:27 AM

Thanks for the valuable inputs folks, I really appreciate it. looks like the beautiful looking well made Losmandy has other issues which makes me reluctant to get it. I rather stick with a expensive Kia and drive it than get a BMW with Hydrogen Fuel cell.

#14 gdd

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Posted 04 November 2013 - 12:38 AM

on the version of firmware i last used, even with no models built up, repeated syncs near one another (such as will happen when running astrotortilla) would create a corrupt model, causing the next goto to go off into hyperspace. completely frustrating when imaging and trying to home in on your target.



Syncs are not supposed to have any effect on the model whatsoever, if they are that would be a bug. Only alignments are supposed to be used to build the model used by the goto functionality. Tom Hilton recently posted on the Yahoo Gemini-2 forum some information about bug fixes and user error scenarioes concerning multiple alignments.

Gale

#15 pfile

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Posted 04 November 2013 - 02:05 AM

lol urinary olympiads!

gale, i know. i have "sync sends additional align" unchecked in the driver; AT is sending sync commands only as far as i know. the popup from the ASCOM driver indicates that a sync happens, not an align.

thanks to AT i run entirely without models. despite this i have seen a model come into existence that is completely whacked out, based on what's in the debug logs.

between the PEC problems (losing the PEC, plus inability to guide when PEC is on) and the problem with the bad models, i just gave up on G2. i know there are others who have persevered and either found workarounds or have been lucky enough to have their bugs resolved in newer firmwares.

i still own the mount and the G2 and hopefully someday it will be stable enough for my use cases.

rob

#16 Raginar

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Posted 04 November 2013 - 08:25 AM

I love my G2. PEC works fine with the recent firmware. I load it each night and yes you can guide with it. If I leave my mount on, it stays loaded just fine.

#17 Tonk

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Posted 06 November 2013 - 11:20 AM

I love my GM-8 and the Gemini I - absolutely no trouble with the older generation stuff :). I'm hanging on to this for mobile imaging. One warning about the GM-8 - you will have to be prepared to be a mechanic to keep the mount trim. I've run mine 10 years and its needed various fettling jobs in that time such as regreasing and religning the worm blocks on three occasions. Dust/grit getting into the gears does appear to be an issue - the worms are no exactly sealed from outside air/dust/grit. When its all working well I have gotten 5 minutes unguided performance when the target is high (> 30 degrees alt). This performance drops when the counter weight goes low. However the mount can play up bad - I had a year were 2 minutes unguided was the absolute limit and with every forth 2 minutes image getting a wild jump (grit in worm)forcing me to strip it down and clean everything.



#18 Startraffic

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Posted 07 November 2013 - 12:19 PM

:blah: The motormouth is back.

BDG,
The last update I did, which is admittedly, several months ago had PEC, PAA, & PAS enabled & working well. I tore my mount (HGM-200) down for an outreach program & have just begun to reassemble it. I found that somewhere in between my G2 has stopped working & I need to figure out what's wrong. :confused: I'm hoping for a blown F1 fuse.

That said, I got my G2 fairly early, before any catalogs, no PEC, PAA, PAS or even the ethernet updating were working. It was a very frustrating time & many folx that clamored for the new GOTO system from Losmandy got something that was not ready for prime time to say the least (myself included. I went from a DDS to G2.). It stunk, & not a little. I started thinking that my G-11 was a worse POS than my LXD-55 (& believe me the "Coffee Grinder" was not a good mount for me). Since then Rene' Goerlich,the software developer, has resolved a number of personal & professional issues that were a distraction. He lives in Germany, & wrote the code from both the Gemini-1 & 2 as a side job. The legend is that he & Scott Losmandy developed Gemini as a "paper napkin" bet that they could put together a world class GOTO drive system for under $1000. G1 was born from that bet & ended with level 4 v1.05. Further development of G1 isn't possible because of space restraints within the ROM. G1 can't read a bigger ROM chip. Parts for G1, in particular the RTC (Real Time Clock) and the Timing crystal became scarce as a normal course of electronics production. As a result of that, Scott & Rene' began, very quietly, developing G2. Somehow word of the Beta version of G2 got out, & Losmandy users stopped buying mounts & G1 until the new GOTO system was available. The clamor for G2 because loud enough that G2 was released unfinished. Updating the firmware was an exercise in frustration as it involved disassembling the Hand controller in some cases in order to format the SD card. Those problems have been solved. To update the firmware, you go to http://www.gemini-2.com/ download the new firmware, reboot & you're done. It takes about 10 minutes to do. There was a copywrite problem with the catalogs getting transferred from Gemini-1 to Gemini-2. As a result of that problem, there was a version that was released that wiped out the catalogs on G2 every time you tried to load them. To make matters worse, you couldn't go back to the old version. One way trip. That was a FUBAR moment, that has also been fixed.
Most of the promised features are finished and the ones that aren't are being worked on. As Rene' enables each feature, it's put out to the Beta group, tested, the major bugs are found, debugged, retested, then put out as the new update. If there are new bugs, (& there always are, because not everyone has the same setup) Rene' monitors the Yahoo group & the user Squawks and fixes the problems on the new feature as they get found. Once he has a good version running, he moves on to the next feature and the process continues. I believe that most of the promised features are now working.

In my opinion, Gemini-2 is now a solid GOTO system, and is ready if not Primetime then for Daytime. YMMV

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#19 hottr6

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Posted 07 November 2013 - 01:15 PM

The Gemini upgrade to non-goto Losmandy mounts include new motors. The standard motors do not have the torque for fast slewing. So if upgrading a Losmandy to goto, you need encoders, hand-control unit and motors.

Have you considered push-to? An easy upgrade path would include JMI encoders, NEXUS and SkySafari on an iPad.

#20 Hilmi

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Posted 07 November 2013 - 01:48 PM

You don't need encoders they are built into the motors

#21 Skyshooter

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Posted 08 November 2013 - 09:09 AM

bdg...
I have a GM8 that I purchased about 6 years ago. It was the plain jane model w/o Gemini goto, only push to. I purchased it this way due to my economic situation. Since then I have upgraded the mount to Gemini II. I, like you, perused the online reviews and forums trying to filter out information that would allow me to make an informed decision. The Gemini 2 and Losmandy Yahoo groups are a good place to start.
I will tell you that I am very pleased with my mount for numerous reasons. There is a learning curve which Gemini-2.com will help you with.
The GM8 is a lightweight well engineered mount that is very well suited for portable use. I take mine out to the mountains quite frequently in the summer time. Now that I have the setup procedure down I get accurate slews with only using three stars to calibrate the mount model. Using more stars will result in better slews but it's not necessary for my work.
Good luck on your mount shopping. Its a very personal thing and the good ones don't come cheap. Do your homework and I'm sure you'll be happy with your decision for years to come.






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