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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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Re: Large Dec Backlash
Hey Ryan, Ryan here.
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I've been where you are.
I wrote this post to explain my approach to the spring loaded worm adjustment:
SLW Worm Block Adjustment See if that helps. Start with the DEC axis as that as where the majority of the backlash matters. Once you get that down you can adjust the RA axis, but you may not need to.... the RA is constantly moving in one direction... backlash is more of an issue when the axis reverses direction, like the DEC does. There are also some videos on the Losmandy You Tube Channel that are handy. Here is a from Losmandy.
There is a learning curve but it is worth it and part of the typical user maintenance. Some advice: Recommend adjusting the worm without counterweights and without a scope, like in the video. It is worth taking everything off the mount. If there is an imbalance, and you release the spring tension too much on the worm gear, the scope can swing around chattering your worm gear on the top of the ring gear teeth and your soul will die just a little bit with every heartwrenching click. If you adjust the bare mount there is very little moment arm to turn the DEC axis unintentionally. Likewise notice in the video that the DEC axis is removed to adjust the RA axis... the DEC axis is pretty top heavy and can swing around with the same heart-stabbing chatter.? Once you follow the directions, you should see an improvement. Each time I notice the backlash creeping up I do the adjustment. It depends on temperature, amount of use, and how much I move the mount around. Took me a couple of tries before I understood what I was doing. ?
Anyways, hope that helps. Let us know how it goes.
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Cheers and clear skies,
Ryan |
Large Dec Backlash
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.?
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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: No phone or internet at Losmandy
Well, the tree line is well below the telescopes on Mauna Kea, to be sure. I hiked it a few years back with an altimeter and I think the last of the large vegetation stopped around 8,000 or so feet, not to mention that the eastern side is usually very wet. But it's right next to Mauna Loa, Hualalai, and Kilauea, with the potential for vog. Hualalai erupts only rarely and it's pretty far away. Kilauea is closer, but the summit is much lower, between 4,000 and 5,000 feet, and Mauna Loa is in the way, plus the winds would carry any vog to the northwest, away from Mauna Kea. But Mauna Loa sometimes erupts along the saddle separating Mauna Loa and Mauna Kea, at 8,000 feet. So, while vog would not likely reach the telescopes directly, an eruption from Mauna Loa could potentially threaten Saddle Road and the observatory access road, which would interfere with astronomers and support personnel reaching the telescopes. The dormitories are at 9,300 feet, a few miles away from Saddle Road, so anyone there could stay there as long as they had supplies, but eruptions can sometimes take a while to clear out. Oh, by the way, vog usually consists of water vapor, sulphuric acid, and microscopic glass powder, among other nasty things, so it's not something you want to breathe or expose your sensitive instruments to. While not as severe as Mt. Wilson right now, even Mauna Loa has its threats. On Wed, Jan 15, 2025 at 1:41?PM Mike Colyar via <mike=[email protected]> wrote:
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