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Re: Gemini 2 Dec cable socket
John, First: I'm glad you used the swap method to isolate the problem as being inside the unit, and not the cable or the motor as first suspected.?? It is a curious issue that the problem comes and goes.? I first thought perhaps one of the optical detector channels A or B is blown...I don't know how that is handled by the logic.? On second thought I like David's idea that a pin of the motor connector came unsoldered and is making intermittent connection.? That idea matches your observations best. It just needs to be inspected at the board level for a solder crack.? If it's that it should be easy to repair.?? Before you take any action, you should ask the company first if they will fix it replace your unit.? Perhaps it is easy to repair if they've seen this problem before.? All product failures should be inspected for weakness in board manufacture, as solder joint failure is a critical quality inspection item.? It is well known.?? Brendan Smith in Australia and David Partridge in UK are experts in G-2 repair, but I've not seen one to fix yet.? I just got a G-2 myself and not disassembled it (yet).? I've asked these great guys if they have seen and solved this problem before.?? On your last question: I have one or two spare G-1.? Contact me if your night time fever reaches dangerous levels! Best, Michael On Sat, Apr 10, 2021, 9:21 AM John Kmetz <jjkmetz54@...> wrote: Thanks, Michael! |
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Re: Using mini PC with ethernet and Gemni II
¿ªÔÆÌåÓýYou need an ethernet switch, then you can connect all the units to the switch. ? You can get really small ones now and I think some run on 12V
? From: [email protected] <[email protected]> On Behalf Of David Malanick ? Looking ahead to my G11 delivery, I was researching Mini PCs for remote access.? |
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Using mini PC with ethernet and Gemni II
Looking ahead to my G11 delivery, I was researching Mini PCs for remote access.?
Always have to go dark sights, not in my backyard. I get cold and would like to stay in my vehicle at times, warm up, nap a bit and monitor mount/camera. I live in Wisconsin, next to Lake Michigan, so it can get 20F colder then inland.? I hate cold! Found this one, looks like good specs and price. 6 USB3 ports! ? My question is how do people run their Gemini II Ethernet connection? I really like the look of the web interface and want to run that on a PC. So, it looks like I would need to run the Gemini II Ethernet to Mini PC Ethernet. But then my Mini PC's Ethernet port is occupied and can't connect back to my remote laptop. I don't think, or know if, running a Ethernet USB adapter on the Mini PC for the Gemini II would work. To me wireless is not really bullet proof enough and I don't want to introduce future technical problems. Hopefully would like to have a 50 to 100 foot Ethernet run. Any thoughts? Thanks, David Malanick |
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Re: Gemini 2 Dec cable socket
John, As Bren says, this design did not use the large round metal DIN enclosure for signal or ground.? All the signals and ground are done on the 6 internal pins. (1 center pin surrounded by a semicircle of 5 other pins.) I think the two "end" pins of the semicircle are the 12-18V DC power to the DC motor.? The other 4 pins are the ground and 5V power and signals A and B of the optical encoder.?? This is why mistakenly rotating the round cable connector and forcing it's pins in the motor or Gemini sockets blows up the optical encoder system (in the motor back) or in the Gemini (that gets the 5V signals) or both...a max of 5V is allowed on the encoder and encoder control chips, so 12 to 18 V to the motor will surely blow the optical encoder parts up.?? To see if it's a bad cable, the cheapest repair: Let's say the DEC motor is running away (could be the RA motor...the procedure is the same) 1. Label your motors as RA and DEC. 2. Label your cables as RA and DEC. 3. Attach the RA cable end to the DEC motor and the DEC end to the RA motor.? 4.? if the same motor is running away, suspect that motor is bad.? Done.?? ?If the "good" motor is now running away suspect the cable or Gemini is bad. 5.? Keep the cables connected to the same motors but now move the connections at the Gemini from RA to DEC. So now the DEC cable goes from the RA output to the RA motor.? And the shorter RA cable goes from the DEC output to the DEC motor.? ?If the problem stays with the formerly "good" motor, the Gemini is damaged.? ?That is, no matter what cable or motor you out in that damaged output, that motor will malfunction. If the problem switches back to the "bad" motor then the cable is bad.? No matter what motor or output you use, anything attached to the bad cable is bad. If the problem is a damaged Gemini,? send your unit to your closest repairer (Bren Smith in Australia, David Partridge in UK, and me in California) for an evaluation and possible repair.? If it is under warranty (under 1 year usage) I think the company will replace it.? Contact them and see.?? It is also possible the Gemini and a motor are damaged.?? Best of luck, Michael On Sat, Apr 10, 2021, 2:41 AM David C. Partridge <david.partridge@...> wrote:
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Re: Gemini 2 Dec cable socket
¿ªÔÆÌåÓýDo bear in mind that the DIN sockets on some G-2 controllers have a tendency to need re-soldering to the PCB (I¡¯ve not seen this myself, but I¡¯m seen it reported here).? That could be the problem or it could be an iffy cable.
? From: [email protected] <[email protected]> On Behalf Of Brendan Smith ? no it has no effect on the motor...its supposed to be a shield but the 6 pin DIN cable has no shield...... |
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Re: Gemini Power Supply Aids in Balancing G11 via Current Readout
Hi Bruce, I make these power booster units as a service to our Losmandy owners group.? I don't have them mass produced, nor buy them and mark them up.? I don't maintain a sales website.? It is just a personal relationship between me and our group. There were several Gemini-1 models having most often, but not always, a 4-pin DIN power jack.? The Gemini-2 are all 5.5/2.1mm input.? I make these units to fit your?needs.?? I created the design to protect the Geminis from a field related failure mode: reverse polarity. If you ever use a portable battery or a boat hookup you know DC systems can be either center positive or negative.? The Geminis have no protection from this common error.? Above that, the built in ammeter and voltmeter find excellent value for optimizing the worm drives...you can see if the worm jams as the current rises past normal.? There is no other way to assess this in practice.?? And you can assess balance from simply slewing in both directions from a counterweight horizontal position.? You can't do that well for the RA axis because the cosine of the elevation angle times the total weight on the RA axis is always present on the RA clutch disk, unless you have a strong enough wavy washer and a mount provisioned for that.? But the wavy washer itself reduces the contact area of the clutch disk.? In any event, the digital display makes the balancing easier and more accurate.?? And if you ever have a motor go bad you can easily see that by the current it is taking.? A bad DC motor will start to exhibit a leakage current, like 0.5 amps extra.? These issues become clear when you have a "dashboard" that you did not have before.?? Similarly I set the output voltage to 17V to give 42% more DC motor torque than the 12 V power input. Setting at 18V is possible, as the output voltage can be easily modified by an internal adjustment.? But for best reliability,? I always avoid upper spec limits, and Geminis are spec'd to 18V max input.? 17V is almost at the 50% improvement you'd get using 18V instead of 12V.?? If you are interested, give me a private email or a call...I'm in California at 408-421-1239.?? Everything I make is guaranteed.? I repair Gemini-1 and 492 units for our group, because they are obsolete products yet can last many decades, and we owners are happy with them.? The Gemini-1 should get a few bulletproofing additions to overcome a couple of parts that are prone to premature wear out.? With the right additions they last many decades.? I do this bulletproofing work; it saves on costoybrepairs later or worse, loss of the unit if it cannot be repaired.?? I also make up high friction clutch disks, so the plastic stock ones do not slip during imaging sessions.? Mine are about twice the friction of the stock clutch disks, so you need much lower knob force in the clutch knobs.? The lower forces reduce warpage or elastic effects like the worm to ring gear contact effects some people experience.?? Anyway, dont hesitate to contact me if interested in these items or other issues.?? Very best, Michael On Fri, Apr 9, 2021, 10:00 AM Bruce via <bruceodelberg=[email protected]> wrote: Hi Russ, |
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Re: Gemini Power Supply Aids in Balancing G11 via Current Readout
¿ªÔÆÌåÓýHi Bruce?yes I also am purchasing This ?power supply from Michael as ?this sounds like such an elegant solution to the balancing problem. I have used the balance function on my Gemini2 controller many times struggling to get those bars down to zero never seen it change much not even certain how this function is supposed to be used, I have not yet seen a discussion nor tutorial about it? ?you need to contact Michael Herman about purchasing one Ron On Apr 9, 2021, at 10:00 AM, Bruce via groups.io <bruceodelberg@...> wrote:
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Re: Spikes!
After over a week of scratching my head. Trying this and trying that, I'm back to imaging again. Target tonight is M53. I would go for a galaxy, but I'm one globular cluster short of getting my RASC Deep sky imaging certificate. Not that I need that for any reason, but it's just fun, and I able to get my kids excited about doing a wide-field certificate.?
I started out with my best balance, no east biasing, and saw some terrible guiding. I tightened up the RA spring, and the stop screw twice. Just a bit really, and my guiding is around 1 RMS, which should be good enough for this target. At some point when I want to tweak things further I'll return to east biasing, but for now I'm taking pictures! Thanks everyone!!!! Jamie |
Michael Herman
David C. Partridge
David Malanick
Ron
Jamie Amendolagine
Mark Wetzel