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Re: 1st time Gemini 1/G11 use
On Thu, Jan 23, 2025 at 04:42 PM, <thomas.clark@...> wrote:
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Welcome to the Losmandy groups!? Many of the folks here are long time users and have a ton of useful info and I hope you find us helpful and that you become part of this great community of users.?
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As a G11 Gemini 1 user the best places for you for all things related to the G11 and Gemini 1 are this group, the Losmandy_users group and the Gemini_users group? Joining these two will get you 99% of the applicable information specifically for your G11 mount and Gemini 1 controller.? BUT if you also join the GeminiII group you will also find great nuggets of wisdom as well as get a handle on your next controller for the future time when you want to make the jump to the latest generation of Gemini controllers.?
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If anybody gets annoyed by you asking question related to Losmandy or Gemini gear that's on them.? We all get along here and if the thread is really not related to the sub group or gets out of hand the mods will say so and move the thread.? In other words don't worry about it, easy peasy.
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Anyway - to answer your question the G11 is an equatorial mount and like all EQ mounts it needs to be setup a certain way to work as designed.? The main issue with the actual mount hardware is that the RA axis needs to be pointed accurately at the North Celestial Pole - NCP for short - and if you do not know it Polaris is NOT the same as the NCP.? The other thing is that the Gemini needs to be configured correctly for your location and know what time it is.? Sounds simple but there are also a few other settings you need to get right for it to actually work and a few more to get it to work well.?
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As others have mentioned there is a dated but still relevant manual for the Gemini 1 located here: written by the guy who wrote the internal code the Gemini 1 is running.? The later Gemini 2 controller is based on the same ideas and at its core very similar.? That said the most useful Gemini related website IME is the website which has basically ALL the Gemini 1 and Gemini 2 stuff in one place.? ? ? ?
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Review these sites, ask questions and let us help you find your way through the Gemini and to a happy tracking mount place.??
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My quick off the top advice is to buy some new batteries for the Gemini 1, to find the correct type of batteries go to the Gemin-2.com site and look at the identification photos to determine what version Gemini 1 you have in hand.? A marginal or expired battery is the #1 issue for most new Gemini owners both Gemini 1 & 2 with a used Gemini.? Trust me just get a few new name brand batteries of the correct type and leave them in the case with the Gemini controller as having a couple spares will pay off in the middle of the night at a dark sky site hours from home as the Gemini 1 controllers are known to eat batteries regularly.?
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Next remove the battery and wait 30 seconds then reinstall the battery and immediately manually set up the Gemini 1 to UTC time, set any local time zone offset, GPS coordinates, mount type etc.? This is the minimum data the mount needs to operate but there are other setup requirements to achieve good tracking and GOTOs the obvious being excellent polar alignment and a known good power supply.??
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Keep us posted on your adventure!?
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Chip Louie Chief Daydreamer Imagination Hardware? Astrospheric Forecast - South Pasadena, CA? ?
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Re: 1st time Gemini 1/G11 use
Hi Thomas, let me be the first to welcome you to the groups. Just FYI, there’s another group tailored more specifically for the Gemini 1 controller. Most of the people who hang there also hang here so this post should do fine here but, if you have more questions relating to the controller, you may want to join that group as well :)
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As for this post, you will need to provide a better description of what’s going on for us to try and help. When you say the mount is not tracking well, what does that actually mean? What are the symptoms you see??
For now I can think of a couple of possibilities:
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1.- Make sure you have the correct settings in the controller, like your location coordinates, time zone, mount type, etc.
2.- make sure your motors are connected correctly and not reversed. Trust me, everyone has made that mistake once or twice lol. Somewhat related, make sure both motors are working when power is applied.
3.- make sure you are properly polar aligned. A gross misalignment will make objects drift off the field of view fairly quickly.
4.- if using a computer, make sure the settings are also correct.
5.- make sure tracking is active in your mount and not set to terrestrial, which basically stops tracking altogether.
There are also physical reasons for the mount to not track well, like a misaligned worm creating a large periodic error or bad bearings causing stiction, but let’s leave those options for last as they tend to be more involved in solving. ?
I’m sure others will have more suggestions but, in the mean time try and give a more descriptive explanation of the symptoms.
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Good luck
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Jonathan |
1st time Gemini 1/G11 use
Hi all. I'm new to Groups, and new to the hobby. I am set up with a very old C-11 on a G-11, with G-1 controller. It has power but is not tracking well.?
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I don't want to be in the 'wrong section', ask the wrong questions, or otherwise agitate others.?
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I know that someone knows how to do it/everything the easy way. IDK if I am on the correct settings on the unit itself. It's tracking, but not following the object.?
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What am I doing wrong?
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Thanks,
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TC |
Re: Cable Snag
One thing I noticed is that your cables are going between the RA and DEC wires.? I would redo the cable bundle to one side or the other, based on which way the flip goes.? It's a good idea, cheap insurance, to test your setup inside.? I would just set mine up inside and run slewing tests with targets in Stellarium for future targets. For flip tests, set a target right before the Meridan and watch how the flip would go 10 to 20 minutes later.?? |
Re: Cable Snag
What I do with the G11 is mimic what the DEC motor cable does by routing the camera cables (power and USB) between the clamp knobs, contained with a silicone band around both knobs. I use a fairly stiff USB 3 cable and I tape the cables together so that they form a gentle arch that keeps them out of trouble. Note I use a zip tie on the side of the Gemini bracket so I can control the length of the arch.
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I've never had snag.
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Re: G11 is more noisy now when slewing
On Mon, Jan 20, 2025 at 04:53 PM, Gary Martin wrote:
This is for tucked-in motor adjustment, but similar adjustment would apply to the older motors, mounted on the outside:
Check out other videos on how to adjust and service G11 mounts in the Losmand Youtube channel:
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Re: G11 is more noisy now when slewing
You may want to contact Losmandy about parts for the non-tucked motor design. My tucked motor G11G2 has two outer spur gears under a black oval cover, and the gearboxes go between motor and bottom spur gear. The upper spur gear connects to a shaft linked to the Oldham coupler, and from there to the worm gear. How the older non-tucked design is done I have not seen personally.
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John
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_____________________________________________________________________________________________________________________________________________________________________________ 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 |
Re: G11 is more noisy now when slewing
First thought is that your drive motor(s) have loosened up and are not meshing tightly. If you loosen the 2 screws and then try to turn the motor CW or CCW and see which makes the sound less, then retighten. I think Losmandy has a YouTube video on this procedure. After that you may need new gearboxes and/or a teardown and relube with the Losmandy approved greases.
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Good luck.
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John
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_____________________________________________________________________________________________________________________________________________________________________________ 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 |
HC Button operation
I don't really use the HC much other than to set safety limits and manually slew around after I adjust the worm gear. During the last few days I've been using it more often for those purposes and I noticed something I haven't before:
After powering on the mount (CWD, cold start) and starting a slew in the RA axis (holding the HC screen up and pressing the physical button on the back left with my left index finger) the mount will start to rotate (OTA west and counterweights east). Let's say that I rotate the mount in this fishing by holding the same button until the mount has rotated 45 degrees to the west and then I release the button. ?
THEN, when I press the same button again, instead of rotating the same direction, the mount will start to rotate back to CWD... then I actually have to press the opposite button (physical button on back right of HC with my right index finger) for the mount to continue to rotate back to the west... from that point the buttons are reversed until cold start when it starts all over again.
no other settings changed. This has happened enough times that I'm not surprised it is happening.? ?
Is this typical? anyone else seeing this?
Is it just a matter of re-installing the HC firmware to maybe fix it? It is a little annoying but I suppose it isn't the end of the world given how rarely I use the HC.
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Thanks
Ryan |
G11 is more noisy now when slewing
Bought my G11 with Gemini 2 new in 2017. I has worked perfectly for all these years with not much maintenance. It does not have the tucked in motors. I just recently noticed it is getting a bit noisy when slewing. I'm used to the normal sound it makes, now it is sounding a bit rough, like it needs some lubricating. I'm pretty good mechanically. Where can I find instructions on how to clean and lube the spur gears, or worm gears ??
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Gary Martin
G11/ C11 Edge HD |
Re: Maintenance
开云体育Mike,I agree with most of what you are saying. I particularly agree that the Anderson Powerpoles have a lot of advantages, they are solid, make a good connection and a solid contact, have good power handling and are very reliable, in fact I have started moving to it completely for my power distribution. I also like the fact that you can colour code for different voltages. It should be noted that many of the electronic components used for astronomy are generally much happier when used indoors away from the weather but we do not have that luxury. Paul
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Re: No phone or internet at Losmandy
I haven't hiked it, but have driven to the top of Mauna Kea.? Fire is probably not a big concern, except for the effect on seeing if a large fire, or volcanic eruption were to occur with winds blowing smoke and gas upslope.? Mt. Wilson is a national treasure though and the thought of losing it gives me some anxiety.? Certainly, the losses to life and property in LA County is the main concern and resources need to be focused on the overwhelming tragedy unfolding for tens of thousands of Angelinos.? Nonetheless, I'm encouraged by the thought that some forethought was given to fire prevention and that it, along with the efforts of firefighters, had prevented an additional catastrophe.? Interestingly, most of the coverage seen in Oregon was concerned mostly with communication facilities at the peak.? A vital resource indeed.? I would be surprised if some reporters knew the observatory was there or understood its significance.?? |
Re: Large Dec Backlash
I've observed the same behavior with my g11g. I took it (mount RA head and mini) in for the software and firmware upgrade and asked Scott to check the SLW. He re-adjusted it and same behavior. I found two things. A really good polar alignment and balance makes the southward slope move closer to the ideal slope but it's not like the slope of my 2005 g11, which tracks the ideal slope very closely. With my g11g carefully adjusted there is some backlash at the point where north and South meet at a point which I attribute to the spring moving to the motor input prior to the worm moving. However, I get very similar tracking, according to phd2, with both g11g and g11. The reason is, in my opinion, the ra axis rarely goes the other way. Phd2 pointing error in RA and Dec is very close with both mounts. Try using the PA adjust tool in sharpcap. See if that reduces the error. I would advise against adjusting the SLW as it takes a lot of practice to get right. Brian valente said it took a number of tries with Scott to get it right. My two cents. Chuck On Wednesday, January 15, 2025 at 01:50:11 PM PST, Ryan via groups.io <jamesryanc@...> wrote: I sent my mount in within the past 6 months to get the L6 upgrade, ra/dec extension, and springloaded worm addong. I started noticing after this it is taking forever to get calibration and after East/West calibration it takes several minutes to clear the backlash ( I get an error that Ra/dec rates differ by unexpected amounts). I did a guide assist and measured my dec backlash which gave me this is the result.? ? ? I am not entirely sure how to fix this or go about adjusting the spring or the dec gears. Any advice is greatly appreciated. My initial guide calibration used to take 1-2 minutes maybe 5 at most. Now its 5-10 minutes. I get the error every time, I will discard the calibration 2-3 times before I can get a good calibration.? |
Re: wheels
I use these under many of my shop tools like table saws and band saws. The wheels are most likely too small for traversing gravel, dirt or grass but the concept is simple and buying one of these to modify might be an economical way to go.
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https://www.harborfreight.com/500-lb-capacity-universal-mobile-base-70222.html
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Mike
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Re: Maintenance
In a better world . . .?
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I’m wintering in Baja far from my scopes and have run out of new places to explore on my dirt bike thus I’m reduced to browsing through the 80,000+ messages on here. Impressive!
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The posts are impossible to categorize easily but a few patterns do catch the eye.
Way up near the top of the list are cable and connector issues. Time and again I read the plaintive cry. “I’m sure it’s not a connection problem. I’ve sprayed all of them and examined every plug and socket.” And time after time, if the petitioner ever bothers to get back to us, it turns out to be, Voila!, a bum RJ plug/socket with an occasional coaxial power plug thrown in for giggles. Time after time.
Lesson learned (perhaps)? “Look under the street light for your contact lens. The light is better there”. Or maybe an equally appropriate bit of advice. “When you hear hoof beats, think horses. Not zebras.”
I started out this grumble saying, “In a better world . . .” we would not have gotten locked in to these wretched RJ and coaxial connections. In the case of the coaxial power plugs, there was really no economical alternative. That has changed. I’ll get back to that.
In the case of the RJ stuff, there are still strong forces sucking at us. The cables are dirt assed cheap and blindingly fast to make up. Never mind that they are horridly susceptible to corrosion and comically weak. and both designs are quick and easy to mass install on printed circuit boards. And at the rock bottom prices that our mounts are being offered, a few cents matter.
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I can hear a bunch of you tuning up out there now about prices. Again and again I read posts crying out that one thing and another should be better built for what we pay for it!
You might just keep in mind that many of these businesses (I’m thinking just now of Losmandy and SiTech) are essentially hobby operations gotten wildly out of control. They employ fewer employees than a tire store and can’t pay them that much more. Many are sidelines of far more lucrative businesses. They will never, ever get back the investment in either money or time that has gone into these products.
I know whereof I speak. I have a general purpose shop wherein I take a customers notion and crank out a very limited quantity of scientific instruments. All the way from foundry to crude and embarrassing efforts at programming with a machine shop sandwiched in between somewhere.
I hold one of these mount or drive system parts in my hand and marvel. I can see making this stuff for these prices if the quantities were reasonable. Like thousands at a time. The computer in your car as an example. But that first car computer probably cost a million dollars to design, build and then re-engineer for mass production. Leave out the mass production and you find our nitch market plagued by our oldest businesses disappearing due to the owner moving into a rest home. And not a fancy one at that!
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Since I’ve already exceeded any polite limit on message length, I’ll stuff in here a plug for a far better power connector. There have totally replaced all other designs in most applications. Probably the first new thing under the sun in a coons age.
https://en.wikipedia.org/wiki/Anderson_Powerpole
Available from damed near everyone.
These have saved me more call backs and complaints than any other component other than a threat with a baseball bat. they are immune to any ‘normal’ abuse’ like rain and filth. When assembled in the agreed upon arrangement of positive and negative leads, they are impossible to get backward. There is no exposed contact to short out against metal things.
in the case of a beast like one of our observatories I use slightly different sizes to avoid cross connecting various voltages. This is covered in the WiKi article and the company and vendor information.
I have used these in pretty much all sizes. On the bottom end, as a way to organize the umpteen different little black boxes I use for astronomy and ham radio, all the way up to high current applications like the battery packs to start fuel dragsters and unlimited hydroplanes. Neither of which qualify as a benign environment!
They can be experimented with using a simple soldering iron but I find that reliability goes up and general hassle goes down with the recommended crimp tool.
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I wish there was an equivalent replacement for those stinking RJ connectors. In my limited production designs I default to Amphenol twist lock units. The least expensive plastic body offerings have never failed me except when exposed to a nitromethane flame or battery acid. Seldom seen in our observatories one hopes. They go together easily either by soldering or with a crimp tool. You can stay with simple pin arrangements or go completely nuts (Already there, I know.).
O.K. I’ll go quietly. No force needed.
Mike
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