Finally a Dobsonian telescope can be polar aligned with sharpcap

[Tiago Ferreira]

I've been doing this challenge without success. The rational/logical first thinking is that "is not possible". Ok, that we know already.
But with the help of Robin from sharpcap i'm trying to succeed on Polar align a dobsonian on eq platform with sharpcap polar align feature.
As i'm human and make mistakes (and sometimes i'm an idiot), is it possible for you to try this with me after monday update too see if we make it work? No rush, we just want to succeed.
I fear that could be possible and by my mistake doing it wrong, mess a great feature for dobsonians.
Please read the topic on sharpcap forum:

https://forums.sharpcap.co.uk/viewtopic.php?f=13&t=4108

Thanks!!

[ouki]

EXCELENT.

[Ubuntu]

This topic will be interesting for @Tibox

[Tiago Ferreira]

It will be like a "mission impossible". But we can try and be the 1st ones polar aligning with sharpcap and a dobsonian. We have nothing to loose in trying.
We just have to push the platform all East to start then when software ask to rotate we push it all West. That's when it fails and ask more rotation but Robin will push the software limits to see if we manage to enter.
I have mine drift aligned with the camera.

[Tiago Ferreira]

Robin has updated the sharpcap 4 yesterday and now the rotation issue is solved.
It works now but it would be important at least one more to try this with me.
I had a windy night and it was very hard to test this, the results made no sense to me so i will try again.

[ouki]

It's a good news,
We wait your test.

[Tibox]

Definitely interested! But no clear sky announced for me till July...
Please share your results Tiago, it's a promising track for our eq platforms

[Tiago Ferreira]

Definitely interested! But no clear sky announced for me till July...
Please share your results Tiago, it's a promising track for our eq platforms

I will. Too windy for telescope today.

[Tiago Ferreira]

I copy / paste the text i've just posted on sharpcap forum:

Well, finally the wind yesterday gave me a break and as the moon is so bright i took the opportunity to test again.
It works!!!
I can do it without problems but it's like adjusting an elephant position ahahah what a challenge.
To make each fine adjustment i have to lift all the set up (almost 50 kg/110 lbs) in the dark with 1 hand while adjust the equatorial platform legs with the other hand and keeping the bubble level precise which implies loosing fine precision. Crazy. But i have a plan and some ideas and i now will work on different techniques to help specially older people to do it without any effort. Patience and time will be the way to go. Also a dedicated fast technique for stressful / urban / young fellows that can't wait eheheh.
First i will play with this for a while because i suspect that for heavy set ups like mine, harder to fine tune, may be better to have a "fair" result on average rather to try reach a "good". I don't know yet. As said, it's like fine tuning an elephant. So i will test, test, test and test until i get a firm conclusion about the best methods and results.
In my case since i upgraded my equatorial platform from 3 to 5 legs a few days ago, i then had to realign it so i was already close with the drift method but was an opportunity to try sharpcap polar align feature. I was on "fair" already and after 1 or 2 "elephant tweaks" i kept on "fair" but a much better tuned "fair". I left it like that last night, as picture below.
The most important is that now we can do it. Finally a Dobsonian telescope can be polar aligned with sharpcap!!
Now i will keep working on this and then i will record a video and post here and everywhere, to allow dobsonian users to benefit from this feature in a smoothest way possible.

SC2.png (281.43 Kio) Consulté 3942 fois

SC.png (200.26 Kio) Consulté 3942 fois

[clouzot]

Nice! Glad you got that sorted out (and that Robin implemented a smaller rotation angle for the polar align feature).
That will probably be of great interest to @AdventDante06 when he's back from limbo.

[kaelig]

Congratulations, a big step for the dobsonians

[AdventDante06]

Well, finally the wind yesterday gave me a break and as the moon is so bright i took the opportunity to test again.
It works!!!
I can do it without problems but it's like adjusting an elephant position ahahah what a challenge.
To make each fine adjustment i have to lift all the set up (almost 50 kg/110 lbs) in the dark with 1 hand while adjust the equatorial platform legs with the other hand and keeping the bubble level precise which implies loosing fine precision. Crazy. But i have a plan and some ideas and i now will work on different techniques to help specially older people to do it without any effort. Patience and time will be the way to go. Also a dedicated fast technique for stressful / urban / young fellows that can't wait eheheh.
First i will play with this for a while because i suspect that for heavy set ups like mine, harder to fine tune, may be better to have a "fair" result on average rather to try reach a "good". I don't know yet. As said, it's like fine tuning an elephant. So i will test, test, test and test until i get a firm conclusion about the best methods and results.
In my case since i upgraded my equatorial platform from 3 to 5 legs a few days ago, i then had to realign it so i was already close with the drift method but was an opportunity to try sharpcap polar align feature. I was on "fair" already and after 1 or 2 "elephant tweaks" i kept on "fair" but a much better tuned "fair". I left it like that last night, as picture below.
The most important is that now we can do it. Finally a Dobsonian telescope can be polar aligned with sharpcap!!
Now i will keep working on this and then i will record a video and post here and everywhere, to allow dobsonian users to benefit from this feature in a smoothest way possible.

SC2.png (281.43 Kio) Consulté 168 fois

SC.png (200.26 Kio) Consulté 168 fois
Ces utilisateurs ont remercié l’auteur Tiago Ferreira pour son message (2 au total) :
kaelig, Tibox
Youtube channel: https://www.youtube.com/c/tiagoferreira ... omy/videos

GSO 12" f/5 Dobson on Geoptik Eartha Eq Platform + ZWO ASI224MC + ZWO ASI294MC
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clouzot
Site Admin
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Message non lu ven. juin 25, 2021 2:35 pm

Nice! Glad you got that sorted out (and that Robin implemented a smaller rotation angle for the polar align feature).
That will probably be of great interest to @AdventDante06 when he's back from limbo.
Ces utilisateurs ont remercié l’auteur clouzot pour son message :
Tiago Ferreira
Docteur ès-Photomoches — D.U. de jeté de monture — Eleveur de sangliers
Tubes : Celestron C9.25 — Celestron C6 — EvoGuide50ED
Montures : Celestron Evo — Celestron AVX — Skywatcher AZ-GTi
Réducteurs/Correcteurs : HyperStar C9 v4 (f/2.2) — EvoFF — Celestron x0.63
Caméras : ZWO ASI183MC — Altair 294c ProTec — ZWO ASI294MM Pro
Filtres : ZWO UV-IR cut — IDAS LPS D2 — Optolong L-Enhance, L-Pro
Focalisation : Celestron Motor Focuser — ZWO EAF
Equipement : NUC 8i5 (RDP) — Sharpcap — CPWI — PHD2 — HNSKY — ASTAP
Avex/Bortle : Magenta/8-9 (en ville) — Orange/5-6 (colline)
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kaelig
RapporterCiterRemercier
Message non lu ven. juin 25, 2021 2:46 pm

Congratulations, a big step for the dobsonians
Ces utilisateurs ont remercié l’auteur kaelig pour son message :
Tiago Ferreira
EQM35 - SW 130PDS & guide Vario finder - ZWO 183MM, ATIK infinity couleur & ZWO 178MC
Sharpcap - Stellarmate (Rpi4 + Kstars/Ekos) - Skysafari Pro 6 - Cartes du ciel - GSS - Windows/linux
Post VA: viewtopic.php?f=9&t=1623&p=59656#p59656
Bib de Liens: viewtopic.php?p=59657#p59657
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Nice! Glad you got that sorted out (and that Robin implemented a smaller rotation angle for the polar align feature).
That will probably be of great interest to @AdventDante06 when he's back from limbo.

Oh yes !!!!! Thanks !

[spica2000]

@Tiago Ferreira seems we have to think about more evolved platerform with fine adjusment ability...

[Tiago Ferreira]

I observe almost all nights and i keep making readings with this PA feature. I make at least 2 readings each session. Lots of readings so far.
At the beginning i was having every night results around FAIR/GOOD/EXCELLENT but since i've changed my telescope weight (lighter now) i'm having trouble to have consistent results with the software although it keeps aligned as i can confirm by the images and drift patterns. I will need more time to figure what happened. Unfortunately i can't shout victory yet with this feature and my set up. The consistency fails only on declination readings and make no sense because it can give an error to the UP side and after one hour an opposite error to DOWN side without any latitude changes in the platform, of course. My bet is that when i reset the platform now, it changes altitude position because of the tube moving. I may try with the springs more tight to avoid the heavy tube to shake.

[Tiago Ferreira]

Unfortunately i suspended this experience a week ago. I have my setup polar aligned by the drift method and using the sharpcap PA feature keeps returning nonsense results. I tried everything i could think but it just can't have consistent readings even knowing i have it aligned. So i give up.
I'm not sure but i think the problem is that my eq platform reset button do the reset fast and with strength and the telescope always bump after reset. Although this doesn't affect the alignment at all and it's comfortable not to wait for the reset too long, it will affect a precision measure from point A to point B as sharpcap do so this can't be done with my setup. It's a beast.
Thus in my situation the drift method using sharpcap live stacking still the best method for me to fine tune, simple and easy, although require time to watch and correct the drift and that's why i put an effort in sharpcap PA feature to work.
At least we've tried, thank you Robin to support this experiment, and the door is open because i believe that this still can be done with a different dobsonian set up. May be someone in the future can make it work and worth...