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Posts posted by savcom
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This has been on my to-do list for months.
A year or so ago I bought an old Helios Apollo 150 on a home-made Dobsonian mount compete with a 15mm eyepiece and a laser pointer, all for £50. I've used it a few times and it's been pretty good, giving clear views and providing a 'wow' factor at a couple of star parties where it's been used. But, looking critically through it, the views have had slightly odd-shaped stars with some coma around them, so I wondered if I could improve things.
Recently, having sorted out the junk and built a second bench in my workshop, I was able to spent an afternoon collimating, cleaning and servicing the reflector. Sorry if this is a little picture heavy.:
Having noticed that there was no central spot or mark on the main mirror, the first step was to gently remove the main mirror, inspect and clean it and then add a small central mark for collimation.
The mirror looked in good shape. Most of this was successfully blown off by the hurricane blower I used.
Measuring where the centre spot should go and then placing the mask at the centre
All done and starting to re-build the scope. Note below the suspension for the mirror - 3x o-rings on each of the three mounting bolts. However, it all went back on with a bit of coaxing
With no eyepiece inserted the centre spot is visible where it should be!
Now we set up and collimate - starting with the secondary mirror
then we adjust the primary mirror to put the laser light back to the eyepiece
Next step was to strip and clean the sticky residue from the focuser. Remove, strip and clean first:
Then some Geoptik Type 1 on the ratchet and worm and then re-assemble.
And finally it's all back together:
But was it worth it? I think so. This is M27 - the Dumbbell Nebula - taken on what rapidly became a foggy night, so less than 30 minutes exposure using an Altair Hypertec 533C. Some purple fringing was removed, but overall not a bad result for a £50 scope and about 90 minutes work.
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I've just added a focuser to my setup and this was the result from its First Light:.
July 9th's 79% Waxing Moon, 275 frames videoed on my Altair 533C through an Altair 72 EDF refractor then grading, stacking and sharpening the image through PIPP, Autostakkert and Registax, followed by a change of colour temperature and some colour gently added in GIMP.
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Welcome to SGL! Looks like we're not too far apart!!
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50 minutes ago, Ian McCallum said:
It's Windows 8.1 64 bit that's running on it.
Still worth doing though.
And, if you're connecting this laptop to the internet, try and make some time to upgrade it to Win 10. It's still free to do.
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2 hours ago, Ian McCallum said:
So after buying a Raspberry Pi 4 with Astroberry, I've just discovered that my old laptop already has a USB 3 port on it! 🙄
With only 2Gb of Ram, it's still slow. I'm wondering if it's worth getting more Ram for it, even if I don't use it for Astrophotography? 🤔
If you can, increasing your RAM will help. Windows 10 itself struggles to be comfortable in 2GB, preferring 4GB. Even then you can often end up with only around 1.25GB left for programs once everything is loaded.
Pricing Samsung DDR3 Ram, I have just increased my laptop capacity from 4GB to 8GB for £20 (Amazon).
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17 minutes ago, Elp said:
@savcom, simply put, as soon as I bought my azgti I sold my Star Adventurer, says it all.
That's worth considering - unless I keep the SAP for wide-field shots or timelapse.
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42 minutes ago, AstroNebulee said:
It does have encoders on both the alt and az axis😊
That says it all. Thank you.
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6 hours ago, Ags said:
@savcom I think you are looking for this:
Regarding AZ-GTi slew speed, you can loosen the clutches and move it quickly by hand without losing alignment.
Thanks for the link. I'll order that anyway after Christmas.
As for the Slew Rate, it sounds as if the AZ-GTI is hampered in the same way as the Star Adventurer Pro - or do I gather that the AZ-GTI has encoders from your comment about not losing alignment?
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I've been looking long and hard at tthis mount, so this thread has come about at just the right time! I have a Star Adventurer Pro, which is great, but the thought of making a simple goto portable system really appeals - and there seems little else to touch the AZ-GTI mount for its capabilities. I've thought about adding a stepper motor to the Star Adventurer Pro to motorise the DEC axis (that may still be something to do while the clouds are here... 🤪) but that may be a step too far (excuse the pun) as the RA-axis will still only slew at 12x Sidereal. What's the slew rate of the AZ-GTI?
As I have the SAP, I also have the tripod, so I was wondering if you can get hold of the pier extension seperately - or do I have to buy the whole caboodle just to get the extension? Does anyone know?
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14 minutes ago, PeterStudz said:
Now I’ve learnt to ask her “what can you see?” Rather than telling her what she should see.
Slightly off topic - but it's always more satisfying to ask your observer to describe what they see - it makes them look a little harder at the object.
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2 minutes ago, mr_belowski said:
Also don't assume that visually dull targets can't create 'wow' moments. The fuzzy grey blob of our nearest galactic neighbour really astonished my 12 year old son - sometimes kids just 'get it' and the thrill of experiencing the very photons that started their journey millions of years ago isn't always lost on them
Don't forget that a youngster can probably see more of the stars in the sky than we can, so their view of Andromeda, for instance, will likely be more colourful and brighter to them than it seems to us. Likewise the Orion nebula.
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A very warm welcome from the Other End of Wiltshire - just south of Salisbury..
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I have tried and failed to balance my Altair 72mm with camera on my Star Adventurer Pro with the supplied counterweight, so I decided to add another counterweight. Looking at the cost of additional weights I thought I could do better for less, so to speak, so I set about looking for an additional 4-500g weight and working out how to add it securely to the shaft.
I'd caught sight of someone else who had managed to balance their Skywatcher Evostar 72ED using a mallet head, so decided to use that as my solution. Here's what I had to do to make one.
First step is ordering the mallet, of course:
Next was to fit it. Easy!
No. Seriously, I did make a slightly better attempt at this....
In short, you need
- a 400g mallet (mine was 60mm in diameter)
- a 70mm M6 coachbolt, an M6 metal washer and an M6 nut.
First step is to cut the handle of the mallet off
The counterweight shaft on my Star Adventurer Pro measures 12mm diameter and is threaded with an M6 thread, so the next thing I did was take some measurements, I measured how much of the 70mm coachbolt was left protuding when it was fully screwed into the counterweight shaft on the Star Adventurer. The answer was 55mm, so the length of the threaded shaft is 15mm.
After this, I drilled a 6mm hole right through the mallet head and widened the wooden handle end to 12mm to a depth of 12mm to allow for a washer and nut to sit on the coachbolt fixing it to the counterweight. This left me with a 15mm length of thread from the coachbolt which serves nicely to attach the counterweight to the Star Adventurer Pro. The end of the shaft goes into the counterweight by about 5mm ensuring a good, solid finish.
Then all that's left is to assemble it:
Final picture is of the new weight (the 'malletweight') against the original 6mm bolt and washer.
Now looking to test all this when it's next a clear night.
Total cost? £5 for the mallet and 45 minutes to think through and assemble. The coachbolt was left over from a previous project and the nut and washer were from my spares drawer. A drop of black paint on the exposed handle end will finish it off when I'm next in the workshop.
This picture shows the new Counterweight against the M6 bolt and washer that were originally fitted.
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It was well worth while listening to. Very interesting.
For those who missed it, it's on BBC Sounds
https://www.bbc.co.uk/programmes/m0011c4p
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On 03/11/2021 at 20:24, Richard136 said:
Just wondering how many of you observe away from the house / garden, e.g., to a dark lane nearby or other dark place.
My garden is relatively dark, but the nearby houses and trees mean the view of the sky is quite obstructed in certain directions.
How many of you venture off into the night to find a dark spot without obstructions?
What a great topic!
I'm very new to Astronomy (I only bought my first real telescope in January) so I'm very much learning the ropes. That said, having just retired, we moved to southern Wiltshire in 2019, a stone's throw from the New Forest and on the edge of Cranbourne Chase, so home is Bortle 4 with no near neighbours and a great view of the sky pretty much all round (there are some trees to the West). Most of my observing therefore is from home, with a couple of forays into the lanes nearby to improve views in a particular direction. My only troubles at home are light pollution from nearby urban areas and the local football club, whose flood lights do just that: flood light everywhere. Hopefully their application to improve their lighting will mean more control of their lights and I can really enjoy the skies. Plans are under way for an obsi in the near future as my interest and experience increases, although I'm also working on what I need as a portable set-up.
My biggest issue is learning my way around the skies at the moment - although this should become easier in time. I have joined my local Astronomy group and they are very helpful, with a couple of Group observation sessions while the restrictions are eased. We've set up an informal messaging system between us that we can all use to track how and where we are observing, so impromptu get-togethers at remote sites can be arranged between us at short notice.
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Thanks @Dr_Ju_ju. I was aware of the numbers, but without numbers on the diagram it's not safe to assume this is the right way round, as the numbers will change if you're looking into the socket, or if you're looking into the back of the socket. If they'd printed the numbers on the diagram then great - we can all follow the diagram as things would be unambiguous.
Just to compound this, I found this post after a little more digging and it just about summarises the issues I am facing:
Short answer: There *is* no standard - even within Skywatcher. 😠
Looks like I'll go my own way and keep my cables specific. At least, using GX16 sockets, I won't be able to plug a skywatcher into it without making an adapter cable up first.
The other approach would be to mimic the standard used on the cables that are commercially available. Maybe I'll look these up and see if I can find which (numbered) pin goes to positive and which to negative.
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Hi everyone
I'm in the middle of building my first power unit for my mounts to be able to use them in the field. I'm using one 12V car accessory socket and four GX16 2-pin connectors in an old metal Ammo Box (I'll pop a thread up when this is finished so you can all comment or suggest features for the Mark II).
My question here is this: What's the pinout standard for the GX12 or GX16 socket? Helpfully, there isn't a standard in industry, although Skywatcher use the GX12 connector as a power feed for their newer, larger mounts (EQ6, EQ8 for example) so it makes sense to follow that standard in my build.
In the manual for the Skywatcher EQ8, there is a diagram of the socket and the cabling:
For the avoidance of doubt, is this view the view into the socket from the outside?
Or is it the view of the rear of the socket where you solder the cables?
Can anyone confirm which way round this is? If anyone has a clear definition or a picture of the cabling that would help me enormously.
Thank you in advance.
Martin
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On 22/03/2021 at 17:31, symmetal said:
As your DSLR files don't include header information like fits files which gives information on where the scope is believed to be pointing to etc. ASTAP and other plate solvers need a hint on where to start doing a spiral search to find a match which it would get from the fits file. I tried some old DSLR images I had taken a long time ago and ASTAP failed initially to solve.
If you give a hint on where you think the scope was pointing to after you load your image in ASTAP, by entering approx coords of the Leo Triplet in the green indicated boxes in the first image below, or double clicking in either box and just enter M65 or NCG3623 and it should find the right coords to fill in. Clicking Solve should then work. If it still fails, click on the sigma icon indicated in red, and you get the scary configuration screens as shown in the second image. 🙂
Thank you so much. This was the clue I needed to start getting images plate solved. Funnily enough, my scope's polar alignment with its polar scope was out and I discovered this by failing to shot the Leo Triplet. I wanted to plate-solve the image to see where I was actually pointing at.
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Another point (particularly with more fragile connectors such as RJ45s or RJ12s) is to remember that these are designed as slide contacts. They do not tolerate much sideways movement, so remember when cleaning these plugs and sockets to ONLY clean in and out of the connector - and NOT side to side across the connectors.
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Any stubborn deposits can be removed with a fibreglass pencil - then a rub down with contact cleaner / IPA on a cotton bud. Wooden stirring sticks are another good choice to help in the cleaning process. Afterwards (and after any cleaning producs have dried off) a little dielectric grease or contact grease will help protect against the elements too.
Try not to touch any bare, exposed contacts with your skin, either.
One of the other tips to remember is that when you finish a session and bring the equipment in, it is allowed to dry thoroughly before being packed away in (say) an airtight container.
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There's a couple of very nice targets for me here - thanks everyone.
Let's hope we get some clear skies soon!! 👍
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1 hour ago, Chaz2b said:
That Toucan did give some very nice pictures, but I can’t use it with win10 so I bought the C270 as a replacement plus trying to keep costs down.
chaz
My Toucam has died, unfortunately - and that's why I went for a C270.
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I have a mixture here. There's a lot of Sodium lights in the eastern distance, a logistics centre on the industrial centre to the north east - but pretty much no stray light and no street lamps near my garden until the local football club practice. These latter are Mercury Arc lights: about to be upgraded to LED, so I will have to stamp my foot to make sure they're adequately baffled.
Skywatcher AZ GTI mount owners thread
in Discussions - Mounts
Posted
Interesting. I had the same issue using the Synscan Pro app last night on Android 13. Ruined my evening, as the mount would slew to target but not let me manually align. The buttons on the app would respond, but no movement from the mount.
I'll check the firmware I'm running and see if it matches your configuration and I'll report back.