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Re: Gemini 2 unit resets to default??
¿ªÔÆÌåÓýI think you mean piqued ¡ ? David ? From: [email protected] [mailto:[email protected]] On Behalf Of Greg via Groups.Io ? ?Brian no I have no problem with torque. It just peeked my interest. |
Re: Gemini 2 unit resets to default??
¿ªÔÆÌåÓýI've run my systems on 12v power for years... but recognize that "12v" is a bit of a colloquialism (12v power is seldom *actually* 12 volts). ?A fully charged lead acid battery is always delivering over 13 volts ... e.g. 13.8v for a new lead-acid battery at full charge. ?After a few years the same battery maybe only charges up to 13.4 volts.... (give or take). ?But if a lead-acid battery wont charge to better than 13 volts... it's probably time to think about replacing it. ?It might be fair to say that your "12v" battery is supplying somewhere around 13.5?? ?The best way to know is to use a meter to test it.I've never had an issue with my mount... but somewhat recently I made some changes. 1. ?I switched from lead-acid (which weighs a ton) to Lithium packs (much lighter). ?But the problem is the Lithium packs (not sure if it's just my particular model or if this is generally a "a thing" with Lithium batteries) is that when FULLY charged, they just barely supply 12v (I've measured it at just 11.9) and as they drain, it can drop to around 10.8. ?But it's Lithium... so I can run them down to empty. 2. ?I bought a new optical tube and this optical tube weighs in at 45 lbs. ?By the time you add other accessories (cameras, finder scope, etc.) it's a bit over 50 lbs (I have 53 lbs of counterweight). ? So I'm thinking ... maybe upping the voltage a touch wouldn't be such a bad idea even though I have never had an issue. So I bought one of these: SMAKN Waterproof DC/DC Converte 12V (9V-13V) Step UP to 15V/15A 15V 15A 225W Power Supply Module by SMAKN: https://www.amazon.com/dp/B00UYCU0A4/ref=cm_sw_em_r_mt_dp_U_RWMLDbWJSB04N I do not believe in using the "cigarette lighter" style plug -- the only electric receptacle that was actually designed so that thing you plug into can self-eject. ?I'm thinking I want something that has a better connection. ?I converted to Anderson "Power Pole" style plugs (I've been converting my friends over to these things one by one... and everyone loves them). ?I can't take credit for this discovery... I'm told HAM radio operators have been using them for years. Keep in mind that the "Gemini" controller (the electronics) is TOTALLY happy with 12v power. ?You will not improve reliability of the electronics by upping the voltage (that will just get converted right back down to whatever the voltage is that runs the Gemini internally ... I'm not sure if it's a 5v system or a 3.3v system and possibly someone here can answer that, but I suspect the boards in the Gemini do not run on 18 volts. When I bought my Losmandy StarLapse ... it was either Scott or Tanya (probably Tanya) who told em that the StarLapse (they no longer make this system) is actually the RA motor from the GM8 mount ... but modified to attach to a photo tripod. ?Also since it's just an RA drive, it doesn't use a Gemini... it has it's only small box that lets you set the direction and drive rate. ?Anyway, they told THAT system runs on ANYWHERE from 7 - 18 volts (quite a range) and that the ONLY thing you get from running a higher voltage is more torque at the motors ... and this assumes you have a load heavy enough to where having the torque is an advantage. ?If you don't have a heavy load ... you don't need the torque. When I bought my heavier scope... I adjusted the max slew speed to 600 (down from the 800 which I think was the factory default). In addition to the G11 mount ... I also own a GM8. ?The GM8 has my TeleVue refractor on it. ?It uses the 7 lb counterweight (even with cameras). ?So I figure I'm probably not in much danger of overloading the thing. ?I didn't bother to up the voltage or slow the slewing rate. On Oct 3, 2019, at 4:00 PM, Brendan Smith <brenatlilydale@...> wrote:
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Re: Gemini 2 unit resets to default??
(¡°What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here?¡±)
Greg.....not sure what your asking but in relation to motor torque you can enter the web interface/servos page and increase motor tracking power percentage. ?Leave slew percentage at default. This allows more energy to the appropriate servo for tracking, lessens stall occurrences. ?Don¡¯t go mad with % changes, just a few % and retest.? Other than that the system runs on 12 V ok.? You stated ¡° the battery did not solve this¡±....I¡¯m confused ....is there an issue here. ?Maybe your own thread? -- Brendan |
Re: Gemini 2 unit resets to default??
The converters are a nice idea. It pumps ~12V DC input, to the correct polarity 17V output (adjustable internally) to the Gemini unit.? It has also has an output voltage and output current meter on it, so I know if there is a motor or gear jam issue by unusual current above normal.? It acts like a power dashboard for my Gemini units.? It aids in worm adjustment also by showing if the worm is jamming.? With the voltage booster I also provide a? 115VAC to DC 12V 5amp unit. Also, a simple cigarette lighter cord unit can provide field power ~12V, and this gets pumped to 17V for better DC motor torque. I have the cigarette adaptor cords too.?? Anyway, let me know privately if interested.? All the best, Michael On Thu, Oct 3, 2019, 10:03 AM Brian Valente <bvalente@...> wrote:
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Re: Gemini 2 unit resets to default??
Hi Greg >>What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here? The Gemini operates best at between 15-18v.? I sometimes use the Losmandy AC adapter (15v) or a voltage upconverter (something like??) Do you feel like you're not getting enough torque?? On Thu, Oct 3, 2019 at 9:49 AM Greg via Groups.Io <gregmorris425=[email protected]> wrote: I just changed the battery in my gemini 2 mini and I used my gps module from losmandy when I powered it back up and it reset time and date pretty quick.? I did this because I'm using a TP-link and my ip address on one startup is 192.168.0.111 and the next time may be 192.168.0.100 which affects connecting. The battery did not solve this. I have 3.2 volts according to a meter and the web interface. ( Which is really really cool). What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here? --
Brian? Brian Valente portfolio |
Re: Gemini 2 unit resets to default??
¿ªÔÆÌåÓýI just purchased a waterproof 12V -> 18V DC-DC converter from eBay with a ?8A rated capacity ¨C works fine.? They¡¯re still selling them for about USD20 or so (see eBay item number 162987841478). ? I couldn¡¯t begin to make one for that price!!! ? David From: [email protected] [mailto:[email protected]] On Behalf Of Greg via Groups.Io ? I just changed the battery in my gemini 2 mini and I used my gps module from losmandy when I powered it back up and it reset time and date pretty quick.? I did this because I'm using a TP-link and my ip address on one startup is 192.168.0.111 and the next time may be 192.168.0.100 which affects connecting. The battery did not solve this. I have 3.2 volts according to a meter and the web interface. ( Which is really really cool). What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here? |
Re: Gemini 2 unit resets to default??
I just changed the battery in my gemini 2 mini and I used my gps module from losmandy when I powered it back up and it reset time and date pretty quick.? I did this because I'm using a TP-link and my ip address on one startup is 192.168.0.111 and the next time may be 192.168.0.100 which affects connecting. The battery did not solve this. I have 3.2 volts according to a meter and the web interface. ( Which is really really cool). What is the best thing to get to increase voltage to the gemini to improve the torque if you guys dont mind me asking here?
Greg |
Re: Gemini 2 unit resets to default??
¿ªÔÆÌåÓýHi Magnus,There¡¯s a known bug in the clock chip (this isn¡¯t something that Losmandy can fix with a firmware update). ?When the battery is changed and it loses the date & time, it starts in a state that causes it to drain power rapidly UNTIL you set the date/time (and then everything is normal again). There are a few techniques to change the battery to avoid this. 1) ?Replace the battery with the unit powered off. ?Once the new battery is installed, immediately power up the Gemini and set the date/time. ? BTW, you do not need to have the Gemini connected to the mount when you do this. ?So if the mount is in an observatory but you¡¯d rather do this inside where it¡¯s warm ¡ just disconnected RA/Dec cables, remove the Gemini module from the mount and bring it in to change it. ?It will likely complain that the motors aren¡¯t working but¡ this wont affect your ability to set the date and time (and you know the reason the motors aren¡¯t responding is because they aren¡¯t connected. 2) ?Replace the battery while the unit is powered on (running on 12v power). ?Take care here to not touch any of the exposed electronics, ?But since the unit technically never lost power it will still have the date/time set. I typically just do method #1 and I always immediately re-order a spare battery (I find local stores tend to not have these sizes so I never want to get caught with a dead battery and no spare). Scott has a YouTube video where he shows how to swap the battery. ?He uses a simple piece of scotch tape so that when he lifts the battery retaining spring he can just pull on the tape and the battery comes out easily. As for voltage¡ The mount runs on 12v-18v power. ?The electronics are completely happy with 12v power. ?BUT¡ if you run the mount on higher voltage then you get more torque to the motors (especially useful if you have a heavy load). ?If you are running a light load ¡ go ahead and stick with 12v power. ?? Clear Skies, Tim
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Re: Gemini 2 unit resets to default??
magnus there's a setting for how gemini boots, "ask if possible" is one of the options. sounds like it's switched to something else
as brendan points out, if it's losing the values you put in, it's backup power related (i.e., the internal battery) yes, it's good to have 15v for gemini ;) Brian |
Re: Gemini 2 unit resets to default??
¿ªÔÆÌåÓýHi! OK, not sure I did that. So I'll do it again. But: I don't see what difference that does.... setting the time and so on, when changing battery? I'll measure the batter too,? soon as I can.
Magnus
Den 2019-10-01 kl. 20:31, skrev Brendan
Smith:
Magnus when you changed the battery did you immediately set DTG.? |
Re: Gemini 2 unit resets to default??
Magnus when you changed the battery did you immediately set DTG.?
Cam you now measure the battery thru web interface is it above 3.0v? Gemini units are very pernickety about backup battery voltage for sure this is your problem. Have even heard of new old batteries being used that were below voltage out of the packet, so also maybe check them with a multimeter.? -- Brendan |
Gemini 2 unit resets to default??
Hi!
I've said this before in this forum, but then it was summer and no astro activity. Now it is fall and I'm up and running again. And this happens on and off - for me, quite unpredictable: When I turn the mount on, it does NOT give me the menu to choose startup mode (COld, Warm, Restart) but just boots. And when I check, the valuyes I'd set are reset to default: speed to 800 (I set it 500), limits to default (and this is really bad, since then automated meridian flips won't work).? I'm running the unit on 12V, I know there have been discussion on that and a 15 V step-up converter is more or less on it's way. I change battery in the spring, not much used since then. So what could it be?? Magnus |
Russell Jancic Passed away.
On the losmandy Facebook page a post that Russell passed away from a long illness. ?My condolences to his family, Scott and all at Losmandy.
Russell was Scott¡¯s right hand man a person of many talents who has helped many in these forums and repairing their units back at Losmandy.? I didn¡¯t know him well he helped me personally enormously, he has a big legacy. ?Goodbye Russell? -- Brendan |
Re: Quite sticky mount
¿ªÔÆÌåÓýWow!.. Wish my G11 had one of those RA Washers! ? Derek ? From: [email protected] [mailto:[email protected]] On Behalf Of John Kmetz
Sent: Sunday, September 29, 2019 9:57 PM To: [email protected] Subject: Re: [Losmandy_users_io] Quite sticky mount ? Franco, |
Re: Modeling mount
Luis, Yes the purpose of the EQmod group program PECprep.exe is to analyze the Unguided PE data, by the method called FFT, and this tells the owner the exact frequencies present in the RA drive.? That program has a top menu selection for G11 and GM8 also...and many other mounts.? The program originally was designed for the Synta EQ6, but was nicely expanded by the authors to cover many popular mounts. If the only large frequency is the worm period (on a G11 this is ~240 sec or 4 minutes.? On a GM8 that is 480 sec or 8 minutes), that is what is desired, and the PE value will be shown (in arcsec peak to peak and RMS).? You desire the PE to be under 2 arcsec RMS for a G11, or under 4 arcsec for a GM8.? The reason is that with the identical worm it should be double that for a GM8, because it's RA ring gear is half the diameter of the G11 ring gear.?? Some people have achieved ~1 arcsec RMS with their G11, or about 2 arcsec with their GM8.? It required a Losmandy precision brass worm, and usually (not always) a Losmandy OPW and a high grade ABEC5 or ABEC7 worm bearings, and a Belleville spring washer.?? The program can also tell you about frequencies unique to different drive gears. That way you can identify a problem mechanical component.? The nice part if the Losmandy system is that RA and DEC components are interchangeable, do you can run experiments to find the best parts for the RA drive. Astronomy is very demanding on equipment...and people.? ?Early astronomers included Gauss, who invented the normal distribution to try and understand the varied data he was getting from other people.? Another was Albert Michelson, who used spectroscopy to (dis)prove the theory of the luminiferous ether, leading instead to the Lorentz equation and finally the theory of relativity.? It is an amazing miracle that our amateur equipment can be made so well that we can expect near perfect tracking from modestly expensive mounts.? We are all seeking perfection and it usually takes extra effort, or extra money, to get closer to it. Very best, Michael On Mon, Sep 30, 2019, 3:16 PM Luis Barneo <lbarneo@...> wrote:
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Re: Modeling mount
I had download your document some months ago. Your advise is unchecked? "Precision Pulse guide" and "Sync performs Additional Align". My telescope is in an horizontal position, the "Western Goto limit (from CWD) should be 0 or 90.00? What is the utility?of EQMOD software? To analize PEC? El lun., 30 sept. 2019 a las 22:21, Michael Herman (<mherman346@...>) escribi¨®:
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Re: GM8 DEC backlash
Sorry that nutty Google is playing new games with my documents. I'll try and attach the file here again. Hope it works. If not, send me an email and I'll send it?to you directly. Best, Michael On Mon, Sep 30, 2019, 1:38 PM Brian Valente <bvalente@...> wrote:
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