Worm phase changed, Gemini I L4
I'm working to get PEC set up and working properly for my MI-250/ Gemini I L4.? Ray G. is providing tech support in the PEMPro forum, here's part of one of his posts:
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"It's probably best to ask on the Gemini forum, but if there is no sensor, then the Gemini would have to keep track of the last PEC index position when powered off and then restored. If the mount's PEC phase changes, it will no longer match the PEC curve uploaded to the mount, which could make PEC less effective or even worse than having PEC disabled."
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I've skimmed through the past couple of years of PEC posts in this forum and didn't see an answer to the specific question I have: what can cause the worm phase to change between different nights (mine shifted by ~24s)?? Is there any way to "bring it back" (such as simply reloading the PEC curve I generated on July 20), or do I need to bite the bullet and make a new PEC run and load a new curve?
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Just to check my understanding, these are the things I can think of or have read about which would change PE (assuming you don't actually change one or both gears):
- Damage to the gear train
- Disengaging the worm/ worm wheel such that the worm meshes in a different place on the worm wheel
- Dirt or grit getting into the gear train
- If the mount/ controller has worm sensors, a malfunction of the sensor
- A firmware problem in the controller
...and problems other than changing PE:
- Bad communication between the controller and computer (so bad comms between Gemini and PEMPro), double check your RS-232/USB cable
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Re: Handcontroller touch action
No one can really say. ?It’s like computer glitches unexpected input. ?It’s possible the HC touch screen (overlaid on the display) has a bad contact area or two in resistance thus sent commands the system didn’t understand or were unexpected.?
Causing the issues. ?But yes if others are seeing the same issue sure it could be an issue. ?I’m sure the code expects x & y positions to be within a certain range ? ?These touch pads to unfortunately go bad with time. ? The first gen HC displays have this issue on a few HCs I’ve seen. ?The failure appears moisture and worn out from usage. ?Not seen this issue so much with newer ver2 & 3 displays (yet?).
if it’s not an old HC and it continues, post here and contact Losmandy.?
if it’s a first ver HC. ?Then definitely it’s the x/y touch pad going bad.?
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see how it goes. But do say if it gets worse
cheers
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Brendan
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Handcontroller touch action
Well, while using the gemini 2 handcontroller I touched/pressed the top line/display zone of the HC.? It went blank and the next goto commanded on the HC led to a runaway slew necessitating a powering down of the gemini 2 unit.??
The warm restarted mount's first goto was nonsensical.
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After a fresh cold start and new alignment model all seems to be normal.
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I dont know if thats normal for gemini 2 ?? But it was scary.? Is this just me or what?? Happened to others?
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GlennB
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Re: David Partridge is available to undertake repairs in the UK from September this year
Congratulations, David! You, Brendan, and Michael are an amazing resource for the community. We’re glad to have you back! ? Greg ?
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From: [email protected] <[email protected]> On Behalf Of David C. Partridge
Sent: Tuesday, July 23, 2024 8:59 AM
To: [email protected]; [email protected]
Subject: [Gemini_users_io] David Partridge is available to undertake repairs in the UK from September this year? As some of you will know I moved house earlier this year and haven’t been able to take on any Gemini-1 or Gemini-2 repairs. ? I now expect that I will be in the position to accept work again in September this year or possibly a little earlier ? Please note well that if you are sending your Gemini from outside the UK, please make sure that the customs declaration clearly states that it is being sent for repair.?? If customs charge me when it arrives in UK, I fear that I will have to pass that charge on to you.? I advise using a competent courier such e.g. DHL who do their own customs clearance. ? Cheers, David
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David Partridge is available to undertake repairs in the UK from September this year
As some of you will know I moved house earlier this year and haven’t been able to take on any Gemini-1 or Gemini-2 repairs. ? I now expect that I will be in the position to accept work again in September this year or possibly a little earlier ? Please note well that if you are sending your Gemini from outside the UK, please make sure that the customs declaration clearly states that it is being sent for repair.?? If customs charge me when it arrives in UK, I fear that I will have to pass that charge on to you.? I advise using a competent courier such e.g. DHL who do their own customs clearance. ? Cheers, David
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Re: Gemini 1 Manual control of slewing
Thanks for all your inputs.? With your help I figured it out.
Benjamine White, I think what you want can be done like this: to "manually" slew your mount using your hand controller, push the keypad button for the direction you want to go. Then, while holding that button down also press and hold the opposite button. That will move your mount at the slew speed you've defined in the setup menu.?
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Re: Gemini 1 Manual control of slewing
Benjamine White, I think what you want can be done like this: to "manually" slew your mount using your hand controller, push the keypad button for the direction you want to go. Then, while holding that button down also press and hold the opposite button. That will move your mount at the slew speed you've defined in the setup menu.?
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Re: Gemini 1 Manual control of slewing
On Sun, Jul 21, 2024 at 12:12 PM, Benjamine White wrote:
Im new to the Losmandy Gemini 1 and am just learning how to use it.? The one thing I have found that I cant do is use the hand controller to manual slew my mount.? I can do an align or select an objet from the data base and the unit slews to the correct position.? But I can not use the hand controller to manualy move the mount for fine tuning.? It is a Level 4 1.05.? It is in sidereal mode and all slew speed.? It comes up showing it is a G11, as it should.? I have tried visual mode and still no luck at getting it to move with the buttons on the controller.? Again, I am a newbie, so be gentle and kind.
Per DP read section 2 about using the menus to set up the the hand controller. The Gemini 1 UI is not obviously intuitive unless you are a programmer. Pay attention to the Gemini 1 menu tree, memorize the top menu structure and modes Gemini 1 can be used in.?
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You will really enjoy Gemini 1 for visual use once you get this. But you need to learn how the HC works and how to set the modes the Gemini 1 HC is working in or you can get the impression that Gemini is not working. Chances are you simply do not have the HC in the mode to slew at your desired speed.?
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Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astrospheric - South Pasadena?
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Re: Gemini 1 Manual control of slewing
The speed at which the mount moves is determined by the Mode (Visual Mode, Photo Mode, All Speeds Mode) and the hand controller buttons.
Download the Gemini1 Level 4 manual from and read in the first instance section 2.3.4 ? The whole manual is worth a good read. ? David
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From: [email protected] <[email protected]> On Behalf Of Benjamine White
Sent: 21 July 2024 20:13
To: [email protected]
Subject: [Gemini_users_io] Gemini 1 Manual control of slewing? Im new to the Losmandy Gemini 1 and am just learning how to use it.? The one thing I have found that I cant do is use the hand controller to manual slew my mount.? I can do an align or select an objet from the data base and the unit slews to the correct position.? But I can not use the hand controller to manualy move the mount for fine tuning.? It is a Level 4 1.05.? It is in sidereal mode and all slew speed.? It comes up showing it is a G11, as it should.? I have tried visual mode and still no luck at getting it to move with the buttons on the controller.? Again, I am a newbie, so be gentle and kind.
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Re: Portable Li power for Gemini1-G11?
Many thanks for all the comments!
I’ve obtained a LiFePo battery and charger and rebuilt my battery box so I’m back in business. Grateful to not have to lug a massive SLA around.
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Gemini 1 Manual control of slewing
Im new to the Losmandy Gemini 1 and am just learning how to use it.? The one thing I have found that I cant do is use the hand controller to manual slew my mount.? I can do an align or select an objet from the data base and the unit slews to the correct position.? But I can not use the hand controller to manualy move the mount for fine tuning.? It is a Level 4 1.05.? It is in sidereal mode and all slew speed.? It comes up showing it is a G11, as it should.? I have tried visual mode and still no luck at getting it to move with the buttons on the controller.? Again, I am a newbie, so be gentle and kind.
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Re: Portable Li power for Gemini1-G11?
The DC-DC converters are effectively a small switching power supply.? Back in the day Meade supplied a small DC-DV boost converter when the LX200 called out 18vdc.? The AC power supply was unregulated crap. But those DC boosters were solid. It was also an easy DIY for electronics geeks. It gave a nice motor performance boost.?
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All these systems were designed around Lead Acid batteries which are actually 13.8v at full charge and shouldn't be drained below 12v under load to prevent cell damage. (About 50% of charge). Operating Gemini 1 below12v also NOT recommended.
So if you were using a regulated 12v AC adapter from a laptops you were underpowered a bit from the 13.8v battery based design to start. AGMs tend to have voltage fall off faster than a marine type L-A but have their advantages too. LiFePo have a much flatter curve and are a good voltage match to LA You can get 80% rather than 50% of the rating before recharge, so not only lighter,? but you can lower the AH spec compared to L-A
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These days DC boost converters are ubiquitous and many can be set for Constant Current (charger) or Constant Voltage, (PSU) the mode you want for use as a power supply.?
The benefit of the higher voltage is only for the sake of the motors, which are the only devices that see the full supply voltage rail.
It improves torque, so may help with guiding as well as slew.
It will cause motors and voltage regulators to run hotter though, so for longevity sake you might want to not run at the max slew rates and always take care to balance loads carefully or you will strain and possibly overheat the motors.?
The simplest DIY is LiFePo, a with a boost converter for the Gemini.?
Add automotive 12v jacks? and tap the battery direct for a 12v dew heater controller and USB automotive chargers for USB devices unless you're running a power distribution box which then needs just a single 12v battery box connection.?
An AC charger for automotive batteries that is safe/ has a setting for LiFEPo completes the project.
If you have LiPo or Lithium batteries as a DIY? I'd recommend designing a 24v (6x? cell) battery pack,? appropriate BMS,? then use 2 DC-DC Buck converters for the 18vdc and 13.8vdc dc outputs.?
For AC recharging, use a 30 vdc power supply and let the BMS manage the charge level since the fully charged float level is about 28v. (6 cells).
The only thing to be careful about is ground loops if you're connecting a laptop that is running on its own AC adapter plugged in some distance away.
That's a different subject entirely.
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Re: Portable Li power for Gemini1-G11?
West Mountain Radio sells battery boxes that can be customized with various switches and meters. You might find something useful there. I believe they also offer batteries but please don’t hold my feet to the fire if I am mistaken!
anyone who believes the bureau of alcohol tobacco and firearms is a convenience store can't be all bad.
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Re: Portable Li power for Gemini1-G11?
Glenn, Excellent, thank you! ?I was eyeing that converter but had not seen the battery box. ?And the battery is on sale!
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On Jul 18, 2024, at 3:46?PM, Glenn S <glennsmooth@...> wrote:
I’m using a DIY custom battery box from Amazon with a 12v 100ah LifePo. ?You can run a 12-19v step-up.?
<img src="https://i.ibb.co/sJ1JFWq/IMG-4667.jpg" alt="IMG-4667" border="0"> ?
<img src="https://i.ibb.co/Gx1YtYL/0479-BEAB-B80-C-413-E-AC20-68-EEE2-AD065-A.jpg" alt="0479-BEAB-B80-C-413-E-AC20-68-EEE2-AD065-A" border="0">
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https://a.co/d/i4jcEbw
https://a.co/d/duwwNLf
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Re: Portable Li power for Gemini1-G11?
I’m using a DIY custom battery box from Amazon with a 12v 100ah LifePo. ?You can run a 12-19v step-up.?
<img src="https://i.ibb.co/sJ1JFWq/IMG-4667.jpg" alt="IMG-4667" border="0"> ?
<img src="https://i.ibb.co/Gx1YtYL/0479-BEAB-B80-C-413-E-AC20-68-EEE2-AD065-A.jpg" alt="0479-BEAB-B80-C-413-E-AC20-68-EEE2-AD065-A" border="0">
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https://a.co/d/i4jcEbw
https://a.co/d/duwwNLf
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Re: Portable Li power for Gemini1-G11?
Chip, Thanks — this looks like a great approach. ?Was there a particular brand of DC-DC converter you used?
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On Jul 18, 2024, at 10:51?AM, Chip Louie <chiplouie@...> wrote:
On Wed, Jul 17, 2024 at 05:53 PM, Mario Wolczko wrote:
Is anyone using a Lithium portable power bank for a G11-Gemini1? If so, are you providing 18V as well as 12V and if so, how?
I went the DIY route several years ago with a $15 heavy duty Craftsman tool box loaded up with a 28ah AGM battery, a smart charger that allowed the battery to supply power while plugged into utility power and when the site power failed continue to supply power to the Gemini 2 and imaging gear seamlessly. The old AGM battery output was wired to a pair of 10A DC-DC converters set to output 13.5VDC and 18VDC as well as a few USB ports with integrated voltmeters.
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Last year when the second AGM battery pooped out and the cost of the LiFePO4 chemistry batteries got cheap I reworked the same $15 Craftsman heavy duty tool box with a 30ah LiFePO4 battery with integrated battery management controller, swapped the old lead acid smart charger for a new LiFePO4 smart charger with a higher charge rate and removed the 12V DC-DC converter to improve efficiency slightly and because the voltage output of LiFePO4 is a flat 12.5V for 90%+ of battery capacity.??
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But be sure to do your due diligence as some brands like the popular Talent Cell do not continuously deliver 12.5V for the full capacity of the battery! Read the battery specs carefully or you may be surprised that the battery only delivers 12VDC for half the battery capacity just like a standard lead chemistry SLA or AGM battery! It is all about the number of cells in the battery, how they are wired and how the BMS is programed.?
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If you read the specs carefully the DIY path is MUCH MUCH less expensive per AH and works like a charm. Also unlike lead acid chemistry batteries - which can only be discharged at MAX 60% of rated capacity without significantly reduced charge/discharge cycles - you can get 90-100% of the rated capacity without reducing the life cycle of the battery.??
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As I said do you homework before buying any batteries or power packs!??
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--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astrospheric - South Pasadena?
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Re: Portable Li power for Gemini1-G11?
On Wed, Jul 17, 2024 at 05:53 PM, Mario Wolczko wrote:
Is anyone using a Lithium portable power bank for a G11-Gemini1? If so, are you providing 18V as well as 12V and if so, how?
I went the DIY route several years ago with a $15 heavy duty Craftsman tool box loaded up with a 28ah AGM battery, a smart charger that allowed the battery to supply power while plugged into utility power and when the site power failed continue to supply power to the Gemini 2 and imaging gear seamlessly. The old AGM battery output was wired to a pair of 10A DC-DC converters set to output 13.5VDC and 18VDC as well as a few USB ports with integrated voltmeters.
?
Last year when the second AGM battery pooped out and the cost of the LiFePO4 chemistry batteries got cheap I reworked the same $15 Craftsman heavy duty tool box with a 30ah LiFePO4 battery with integrated battery management controller, swapped the old lead acid smart charger for a new LiFePO4 smart charger with a higher charge rate and removed the 12V DC-DC converter to improve efficiency slightly and because the voltage output of LiFePO4 is a flat 12.5V for 90%+ of battery capacity.??
?
But be sure to do your due diligence as some brands like the popular Talent Cell do not continuously deliver 12.5V for the full capacity of the battery! Read the battery specs carefully or you may be surprised that the battery only delivers 12VDC for half the battery capacity just like a standard lead chemistry SLA or AGM battery! It is all about the number of cells in the battery, how they are wired and how the BMS is programed.?
?
If you read the specs carefully the DIY path is MUCH MUCH less expensive per AH and works like a charm. Also unlike lead acid chemistry batteries - which can only be discharged at MAX 60% of rated capacity without significantly reduced charge/discharge cycles - you can get 90-100% of the rated capacity without reducing the life cycle of the battery.??
?
As I said do you homework before buying any batteries or power packs!??
?
--
Chip Louie Chief Daydreamer Imagination Hardware?
? ?Astrospheric - South Pasadena?
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Re: Portable Li power for Gemini1-G11?
I use the next one: BEAUDENS Generador Solar Portable ?
Is anyone using a Lithium portable power bank for a G11-Gemini1?? If so, are you providing 18V as well as 12V and if so, how?
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Re: Portable Li power for Gemini1-G11?
Thanks for the reply.
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The reason I ask is that when I first got my G11 (20 years ago!) the goto performance of the servos using 12V was awful -- many stalls. 18V fixed that.
So I want either (a) a power bank that supplies 12V and 18V, or (b) a recommendation for a solid 12-18V converter. ?Converting DC to AC and back to DC seems terribly inefficient. ?The SLA battery in my current power pack is spent which is why I'm looking for a replacement, preferably a lot lighter, but in the worst case I would just replace that battery.
I don't image away from home so I don't need to power a laptop or camera, but I do need power for dew heaters as well as the mount.
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Re: Portable Li power for Gemini1-G11?
Depends on what power bank you get. I got a bluetti type a while ago to deal with frequent power outages at home and have yet to try it with my mount. Those types come with AC outlets, 12V car lighter outlets, as well as USB. In my case I would use one of the AC outlets for the power brick that feeds 16V to the mount and the other would be for my laptop. The car adapter would be for the camera and other 12V accessories.
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If your power bank only has 12V you can still use it with the Gemini and everything else, except a laptop maybe. If you have a mini PC or the AAir then you’re set.
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Jonathan
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David C. Partridge
Chip Louie
Ma Ol