Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Ummm My calc's for the tracking divisor are different:
RA divisor = (1,500,000/prescaler)/(steps per rev/worm period)
Steps per rev = 256 x 125 = 32,000
Its a G11 isn't it??? Thus worm period is the same 239.344658
Pre-scaler = 1
Steps per worm revolution = 32,000
Thus Ra divisor = ((1,500,000/1)(/32,000/239.344658)) = 11,219.2??? This is my figure?
Even if its a Titian I get 14959......
I'm confused about how you got a Ra divisor of 89754
--
Brendan
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
On Thu, Jun 24, 2021 at 05:34 AM, Ray Gralak wrote: Ray,
1. Either your graph is incorrect, or PEC is introducing a lot of drift. By the end of the worm cycle the accumulated PEC value should be 0 (but it's not).
I tried numerous times last night to create a PEC curve that starts and ends at zero or the same point. If you try to use any curve that does not you will of coarse get a sudden jump in guiding so they are not usable and one has to keep PEC turned off.? My only though right now is the RA tracking divisor of 89754 ought to be 89754.2. If you let the mount track for a couple of hours the mount does fall behind quite a bit. This problem will apply to any gearbox ratio other than 25:1. The only solution that I can see is? to download the PEC curve and not use Gemini II to calculate it. Peter
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Hello,
I am moving for work and need to lighten my load a bit. I have a losmandy gm8 with some extras for sale if anyone here is interested or might know someone who would be. I'm in Southern California for any local purchase possibilities - posted on astromart here -https://astromart.com/classifieds/astromart-classifieds/mounts-equatorial/show/losmandy-gm8g-w-polemaster-and-lw-tripod-w-scoperoller-wheels
Thanks,
deke
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Indeed, thank you. I did not even realize there were two ways to align it.
Now it lines up with the leg! It does put the alz-bolt a bit close to the bigger knobs, reducing clearance but I can definitely still adjust it!
You would likely laugh if you saw my little 60mm scope sitting on this thing :)
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Do you have a picture of your setup showing this??
It's possible you may have attached the RA axis with a different bolt alignment
Sorry for so many questions here, but in the video you say to align a leg north, which makes absolute sense.
However, no matter how I put the mount on the tripod, it wont do that.
I notice some allen bolts around the bottom of the base - are these for aligning with the leg (i.e. loosen them all, rotate the head until if faces directly over a leg and re-tighten ?)
My mount always lines up between two legs (I have taped the ground for now to allow me to get it back in place)
-- Brian?
Brian Valente portfolio
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Sorry for so many questions here, but in the video you say to align a leg north, which makes absolute sense.
However, no matter how I put the mount on the tripod, it wont do that.
I notice some allen bolts around the bottom of the base - are these for aligning with the leg (i.e. loosen them all, rotate the head until if faces directly over a leg and re-tighten ?)
My mount always lines up between two legs (I have taped the ground for now to allow me to get it back in place)
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Makes total sense. Wish I had ordered the altitude knobs. It didn't look like something I ought to be adjusting so I left it but now I know. Will definitely do this when I do the next alignment
Thank you so much !
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Correction: *The mount will take some time to settle if the threads are NOT completely engaged.
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Nick,
Just a quick suggestion: it's in Brian's video, but try rotating the altitude knob such that the telescope increases in altitude on your final adjustment.? If you are adjusting to a lower altitude, you might be floating between the threads in the altitude screw (especially if your locking screws/knobs are tight).? The mount will take some time to settle if the threads are completely engaged.
-Dwight
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if you already know how to use polemaster (and it sounds like you do) then these tips may help you avoid ending up with a less accurate PA result
>>>I loved the other intro videos that you did - super helpful in getting me up to speed rapidly cool thanks :) questions or suggestions always welcome
On Fri, Jun 25, 2021 at 12:00 PM, Brian Valente wrote:
I just did a video starting the polar alignment video turtorials, this included some tips here on how to iterate on tightening the bolts. Might be helpful for you?
?
Fantastic ! Listening now
I loved the other intro videos that you did - super helpful in getting me up to speed rapidly
-- Brian?
Brian Valente portfolio
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On Fri, Jun 25, 2021 at 12:00 PM, Brian Valente wrote:
I just did a video starting the polar alignment video turtorials, this included some tips here on how to iterate on tightening the bolts. Might be helpful for you?
?
Fantastic ! Listening now I loved the other intro videos that you did - super helpful in getting me up to speed rapidly
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Hi Nick
I just did a video starting the polar alignment video turtorials, this included some tips here on how to iterate on tightening the bolts. Might be helpful for you?
Hey folks, I got my new G11 out last night (just took delivery)
Definitely worth the wait time. Everything is super solid and looks awesome
It was fairly cloudy so I was just doing initial setup.
I did notice one thing though. I use Sharpcap for PA and got an "Excellent" measurement
Then I did a quick guide assistant for a few minutes, and it reported I was around 9 mins out of PA
I slewed back to Polaris and sure enough, it was now reporting a poor/fair PA of about the same
I adjusted initially with the Aziumuth locking bolts pretty snugged down, so I doubt that made a difference. I also didn't see any instructions to lock the Alt bolt, so I just adjusted it and left it (looks like I would need an Allen wrench to do so ?)
Most of the error was in alt when I went back so I'm wondering if I need to do anything to those locking bolts?
-- Brian?
Brian Valente portfolio
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Hey folks, I got my new G11 out last night (just took delivery)
Definitely worth the wait time. Everything is super solid and looks awesome
It was fairly cloudy so I was just doing initial setup.
I did notice one thing though. I use Sharpcap for PA and got an "Excellent" measurement
Then I did a quick guide assistant for a few minutes, and it reported I was around 9 mins out of PA
I slewed back to Polaris and sure enough, it was now reporting a poor/fair PA of about the same
I adjusted initially with the Aziumuth locking bolts pretty snugged down, so I doubt that made a difference. I also didn't see any instructions to lock the Alt bolt, so I just adjusted it and left it (looks like I would need an Allen wrench to do so ?)
Most of the error was in alt when I went back so I'm wondering if I need to do anything to those locking bolts?
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Paul,
Yes indeed. Through Michael Herman I have communicated my thoughts and specifically what might be a bug. I'm hoping Rene will in time clarify things. It is important to know the true limits of the system and have an accurate spec.?
Peter
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
That's good to hear, Peter. Since the document I referenced is directly from Rene, the author of Gemini, I'd like to hear from him before making any corrections to it.
Regards,
? ? ? -Paul
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On Thu, Jun 24, 2021 at 06:22 PM, <pcboreland@...> wrote:
Paul,?
I've confirmed that PECmax can be set to 32000 and everything works just fine. I monitored the PEC index through the web interface and it counts up to 32000. It's clearly misinformation. I'm glade I decided to test the limit for myself.
Peter
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Paul,?
I've confirmed that PECmax can be set to 32000 and everything works just fine. I monitored the PEC index through the web interface and it counts up to 32000. It's clearly misinformation. I'm glade I decided to test the limit for myself.
Peter
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
By serial command.
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On Thu, Jun 24, 2021 at 11:53 AM, crocco1250 wrote:
Paul
Is the pecmax value set by serial cmd or by the webpage?
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Paul
Is the pecmax value set by serial cmd or by the webpage?
Chuck
On Wednesday, June 23, 2021, 09:02:07 PM PDT, Paul Kanevsky <yh@...> wrote:
Hi Peter,
PECMax value can be set by a command to Gemini. This can even be multiples of the worm cycle. I'm sorry if you already know this, I'm not up to speed as to what you're trying to test.
Regards,
? ? ?-Paul
On Wed, Jun 23, 2021 at 10:12 PM, <pcboreland@...> wrote: Tonight I was able to test? if the PECmax limit? was indeed 25600 as some have suggested. As this image below shows the the counter went up to 3200 and rolled over. I run the test using a synthetic PEC file I created. The fact that PEC would not record the PEC curve correctly with the steps per worm revolution at 3200, is I think a separate issue. Using PEMProp I should be able to create a PEC curve and download it to the mount.? Keeping fingers crossed.
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Re: DIY Spring Loaded Worms for the G11
Hi Brent -
I was able to test the new motor mounts last night, and they seem to have worked well.? We had a nearly full moon, and poor 2/5 seeing conditions, but nothing jumped out at me as an obvious problem.? The mount was happily guiding at .8 arc-sec rms at 23? above the south horizon.? Fairly challenging conditions to guide through, for certain, so I was quite happy with anything under an arc-sec.
I think I'll wait for you to test the brackets out as well, and if they work for you too, Ill make them available on Thingiverse, along with the spring loaded worm components.
Thanks,
-Tony
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Re: Changing the servo motor encoders from 256 to 512 or 1024. Any reason not to do this?
Maybe this can help.?From?
Regards,
? ? ? -Paul
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Paul Kanevsky