FrenchyArnaud

Defo looks like a GSO/Orion... 
But even if it is not, it actually is not relevant. Assuming you are not proficient in the domain (sorry if you are and what follows is patronizing) , if you give us carefull dimensions (diameter of main mirror, tube length) anyone with even minimum experience will be able to calculate the main optical characteristics (focal length, F ratio etc) and to point you to the relevant infos for a good start. 

Ok, so this is my first half decent  night with  full on imaging attempt. And I have to say, it was all totally worth it. 

I struggled a bit with balance then with calibration and eventually realised I have a major dew pb that needs addressing, but as it stands, despite a very mediocre seeing and a dec backlash measured at 5000ms (which forced me to spoil the PA to 3" to be able to guide South only) I currently have the best guiding I ever achieved with this 20yo battered mount! On average 0.80 arcsec, with lows to 0.65arcsec and highs of 1.05arsec (for ref, my camera + OTA has 1.83arsec/px ) Critically, pretty much 100% of subs are perfect (except for satellites of course) and it took me seconds to be in business. Of course, I have spent a few night in between working on alignment and calib but it is clearly doing ok now. I will now be able to take advantage of even very short cloud clearings! 

So... Yeps, defo worth it, I should have done tht years ago.  I need to sort the dew issue and build my autofocuser and I will be all set for a little while! Unless of course, I decide to take the mount apart and try to service it... Which is not totally excluded 😁

On 14/02/2023 at 18:37, FrenchyArnaud said:

I am looking for alternatives to the zwo that are more affordable, not found anything yet though. But it will be totally automated at some point, that is for sure  

Well, no points for guessing what's happening there. 

New thread coming up soon...

2 minutes ago, CraigT82 said:

Nice work 👍🏼Looking forward to the first images from the new pier. I’d also say go for the EAF or whatever motor focuser… you can the just automate it all, set an imaging run going and just go to bed! 

Thanks!
Yes, that's the plan. I am looking for alternatives to the zwo that are more affordable, not found anything yet though. But it will be totally automated at some point, that is for sure  

13 minutes ago, Graeme said:

That turned out really well Arnaud. And for a good price too! I hope you get many years of use out of it.

I would say go for the EAF.

Regards

Graeme

Thanks
The EAF will come for sure - or an equivallent anyway. It's just that right now my budget has taken a hit with the build. I am looking into cheaper options but apparently it's not that easy to find. It will come at some point anyway!

20 minutes ago, StevieDvd said:

Is that you in the last image, or did you get a man in to do the job and uploaded the wrong image? 😀

But to be serious I'm happy to see the end result and can't wait to see your astro images in further posts.

Bravo Monsieur

 

Yeps that is my ugly mug right there! Ugly but visibly happy 😁 I was reassembling everything (cables essentially) and the GF snapped it on her phone. Because, even if she is a proper pita on a daily basis, she is sincerely happy for me. In fact, she insisted that I should do it rather than wasting my life and nights carrying the stuff around. She's a gem, I just need to make sure she does not know it 😁

Well, i's all done! Now waiting for the next acceptable evening to do the PA and the inaugural session

Following the azimuth bolts incident, I tapped the nuts from M6 to M8 fine pitch (that is, preserving the original 1mm pitch and not going to 1.25mm) because I thought that would help with the precision of PA.  So as it stands, all PA bolts have been upgraded , M6s became M8s and M8 became M10s. I need to use a tool to turn them but that's ok - I am no longer supposed to do it daily. I might still insert a PTFE sheet under the mount base later on; for now a good spray of lithium grease will have to do. 

I buried the cables and pulled the 12V to the pier, passed both USB and 12V through the kitchen wall, ripped the last slabs and put the last gravel on. This is the finished product; I may in the future clad the pier with wood. For now, protection is provided by a bike waterproof cover sheet thingy  - whatever the actual name is - and the definitive cover is on its way. 

The only actual upgrade I am already considering is a zwo EAF - then I could 100% play from inside with this new toy! The few tests I have made the past few days confirned everything is working as it should and that it is ridiculously easier and faster to have everything running: it now takes about 45 seconds "to be in business" instead of my normal 90mins. Once the PA will be properly done, and decent calibration achieved, even with the focus to do by hand with a bathinov it will be under 5mins.  So... yes, happy days! 

The final bill?

Well, the first Jewsons bill for blocks concrete etc : £70
masonery drill bit (24mm*450mm) : £10
The whole of the gravel : 20*£4 approx.
Bits and bolts (taps, fine pitch bolts etc) about £12
USB with repeater : £12
12V bits : £20
BBQ cover : £25

Total : about £230 but that included resurfacing this half of the garden, about £150 without the gravel which is, after all, not directly used by the telescope. 

4 hours ago, saac said:

One of the first things to consider when you ask a question is surely the competence of the person you are asking. This would hold true for an AI or person. At the end of the day, AIs are doing nothing different from people in that they are passing on received knowledge. AIs of course will ultimately have the edge in that they can accumulate a greater pool of knowledge than any individual. 

Jim 

You see, that is precisely where this sort of AI is absolutely superior to people. It basically stems from 2 basic factors: 

1) NOONE evaluates all those involved in a virtual conversation (for instance, did you really check I was neither a bot nor a cybernetics expert?)

and

2) the vast data collection of AI is way past any reasonable human effort and that makes it different in nature. Most poeple think the plural of anecdote is data - it is not. You know, it's the  "don't buy a Ford, they are s**t. I should know, I had 3. Never again!" sort of opinion. 

To me by default that makes the google/alexa/siri/chatgpt/you.name.it answers more valid than poeple's opinion, until such time one particular individual has shown to know/understand more than them. There is a handful of experts I totally trust on specific topics - more than the machine for sure! But these are better informed than non vetted expert (including known personalities as known does not equate competent)

In other words: AI ALREADY has the edge. And the gap will grow at the rate of universal inflation, we will never ever be able to catch up. 

1 hour ago, iantaylor2uk said:

If you ask the right people you will probably get much better advice than if you ask the average person. The chatbot will most likely be in-between.

That sounds about right to me 👍

21 minutes ago, EarthLife said:

Yes but humans are experts at making up and posting mis/dis-information.

Trying to convince the world at large (inc 'experts') just 30 years ago that our star is not the only star with planets around it was an impossible task.

I am not disputing this, but for the sake of discussion I need to point out that this is a self-defeating argument : 

- Ask real poeple, not a robot.

- but the robot asked poeple in the first place and repeats their common opinion.

- yes but poeple are misinformed therefore the bot repeats wrong information.

it automatically follows that "ask real poeple" is bad advise, one cannot have it both ways. My point is that at this stage of technology, the bot's advise is to be considered, surely not as the ultimate answer but at the very least equal or superior to the half baked opinion of Johnny on internet. It does not mean individuals have to agree with the bots answer to a specific question; only that the bot's answer are on average superior to Johnny's. Point in case: this particular bot just passed law school. Most internet users could not, ergo if i have a legal question i am better off asking the bot than appealing to internet and its "real" people.

Again, pointing it out just for the sake of friendly argument 🙂

On 09/02/2023 at 01:08, nfotis said:

Never trust a story teller, only actual users.

ChatGPT is *not* a search engine, it assembles persuasive text from a large amount of existing text.

 

N.F.

 

There is an argument to be made that this existing text was written by users for starters and that therefore, the answer provided through machine learning is the most accurately representative of the human group opinion. I will let that here and let you ponder

2 minutes ago, CraigT82 said:

On my old EQ6 I used sheet PTFE 1mm thick (Amazon, about £8 I think for a 200mm square sheet).  I cut a circle out of it and placed it between mount head and tripod top.  Made polar aligning much easier - mount head, scope and counterweights totaled about 70kg so a lot of friction was present!

That  sounds like a great pointer, I will investigate that straight away 👍

58 minutes ago, FrenchyArnaud said:

I just realized that my azimuth bolts are dead (inner threads of the "nuts" are pretty much smooth) which means I need to do heavy repairs if possible or the mount is dead 😞 A bit gutted but trying to stay positive

Ok so I took the whole thing down and had a proper study of what is happening here. Let it be a lesson for everyone! Explanation: 

The azimut bolts (M6) are obviously pushing on the azimuth pin as they are screwed in. So, when you screw in you push the mount AWAY from the pin. If you screw the left bolt in, it causes the mount to rotate counterclockwise. Seems obvious? It is important to keep it in mind.

When I drilled the azimut hole to put the pin in place, rather that taping the hole and screwing the pin, I drilled .5 mm larger and screwed the pin through the disc using the thin bolt originally present. I did not think much about it ; it was an easier way with no foreseable negative consequence. 
How wrong was I.

The azimuth bolts are very, very tired, threads smoothened on bolts and nuts and maybe not as straight as they used to be. Consequently, they have quite a lot of play when not under load. The pin without the thin support bolt is 3mm shorter on the brake disc than the original config. And when you screw the left az.bolt in, the mount rotates counter clock wise. Still with me? The brake disc has more friction than the original bed of the tripod or maybe I over-tightened a bit. In any case, screwing clock-wise which rotates counter-clockwise produces a torque, vertical, downward on the pin. But the pin cannot move down, so the tip of the bolt moved up (it could, because there is so much play) and because the pin is now 3mm shorter, the bold was able to wedge itself between the pin and the roof of the central bolt support. So obviously, the more I tried to screw it in, the more I was wedging it in and my polar alignement was not going smoothly, the azimuth jittering randomly depending on the tension... 

So here is the lesson: if it does not go as planned, if it does random things that makes no sense, DO.NOT.INSIST. Stop and think. I was just in too much of a hurry to try. I did not take the time to assess. 

The good news is, I can fix the mount: I will put the thin bolt back where it belongs, for starters. I will tap the M6's into M8's to restaure minimal jitter (plenty of meat around the hole to do that safely) and I will put a tad of vaseline where the mount rests on the disc to avoid unwanted metal friction (and tension)

The bad news is, I am a cretin. Not just because I did insist without thinking, but because I had a very similar incident with this same mount last year, and ended up taping the alt.up bolt with an M10, which very much improved the behaviour of the mount. Still did not cross my mind this time! 

3 hours ago, Peter Drew said:

As the originator of the "Todmorden" pier I'm always pleased to see another one take shape.  Also pleased to see the mount bolted or fixed through the top of the block rather than a rat's cage.       🙂     

Nice to meet you 😁

2 hours ago, Graeme said:

That's a fine looking pier Arnaud. And a very nice disc, it looks like the one I have!

Good luck with the first light.

Are you going to build a roll off roof shed around it?

 

Thanks! Yes, fine disc 🤭

No roll off shed, there is just not the space.

I just realized that my azimuth bolts are dead (inner threads of the "nuts" are pretty much smooth) which means I need to do heavy repairs if possible or the mount is dead 😞 A bit gutted but trying to stay positive

Thanks to @Graeme who took the pain to drill the disc to specs before shipping it (it was delivered this morning but I was working) the pier is now assembled and as luck would have it, will see first light tonight! The cabling is not done yet but of course,  I will simply use my usual cable set up. 

The disc is simply maintained by 2 expanding M10 bolts and the central axis of the mount; it is also glued with the rest of the CT1 to absorb any irregularity of the concrete and make sure there is no possible oscillation. There is no levelling system obviously but it is pretty much dead straight anyway.

The whole thing is solid as a rock and I am very, very pleased with myself! 

Did you know? In stellarium you can create your own custom landscape which, with a bit of creativity and fiddling, allows you to see the occultation with a decent accuracy (in my case, under 10mins) Pretty cool when like me you shoot from the backyard and have major obstructions. The idea is to create a panorama (from the top of the pier or your usual tripod place) and to install it over the celestial projection. Here's mine and I think it is a rather cool feature.

11 minutes ago, chubster1302 said:

Thought usb's had limited run lengths ?

That's what they say.  Hub+5m+5m never gave me an issue, even though it's only usb2 and even though it's supplying power to the guide camera and even though it's downloading the raw files of the camera directly to the PC. So... I stopped being worried about cable length years ago. In my mind, if the computer usb gives 5v (they don't all do) it will work. I actually tried to test transmission speeds with 4x 5m (so 20m total) some time ago and could not see any signal loss, deconnexion issue etc. I assume it is true to an extent as it is part of the usb specs but... the simple fact is: as the video shows, it works. Even with multiple connexion points in line. Facts are terribly stubborn. 

-ignore-

For years (and it will sill be the case once my pier is in service) I simply had a 4 way usb hub like this one : 
 

which sits inder the mount on the tripod, and where dslr, guide camera and mount handset are plugged. This hub is in turn plugged into a 5m USB extension cable which comes either into my laptop or into another 5m extension that goes to my main computer in my office. This 2x 5m basic cable does the trick. See video here : 

Day 4. Keep in mind, I work full time so I only have about one hour a day at most to work on that and a few hours at the week-end. 

So, after sleeping on it I decided my 5m USB cable was unsuitable, too short on the pier side and not giving enough play in the inside of the house. I think I will just make my own life miserable forever if I do not have enough room to play with. So I ordered a 10m USB3 with repeater, and I will exchange the cable as soon as it arrives. Fortunately, by conception it will be quite easy. 

In other news, I brought in an extra 150kg of gravel and laid it! So the gravel is now about half way through and it begins to give a good idea of what it will be like when finished. 

So now I am waiting for the delivery of the adapter plate AND the long extension... And as soon as they arrive I will be able to finish it all  and at long last, to see my OTA where it belongs! 

34 minutes ago, M40 said:

Superb 👌can I suggest that before you rip the rest of the slabs up, have a think in case it could be a concern for the neighbours. All the best.

Thanks.

Yes, valid point that we discussed. That is already sorted 👍 In any case, objectively apart from the dog (and me to put the teleacope cover  on/off) noone will walk there at night. I am more concerned about the resident foxes and cats seeing this new expense as a litter tray / playing ground 🙄

Ok, Day 3!

So after long discussions with the GF, we decided that it would be better to get rid of the tiles altogether and cover the whole area with gravel like the flower beds. To me this offers multiple advantages: it's economical, easy, and allows me to bury the cables which in turn avoids fiddling with pipes running all around the garden. Besides, I have hope that the 3" of gravel will be sufficient to dampen any vibration the occasional step there could produce. 

So, step one : ripping a line of tiles out, which involves a very high tech, scientifically approved method (brute force), an operation conducted with precision instruments (42" crowbar) The objective is to lead the cables (USB and electrics) to the hole in the outer wall where an unrelated cable is already present (red arrow)

Then I put the cables down and covered them with a pvc profile screwd directly into the grout that was the base of the tiles. 



After that I just had to dump the gravel. I did not take the pain to wash it, I count on the rain for that - hence the difference in colour with the flower bads. Later, (when the pier is operational) I will rip the other tiles and make the whole area covered in gravel. 

The next step is to

1) drill a wider access in the masonery (20mm) and pull the cable indoors. This cable will be powered by a 12V 8A unit which I already have. (more than enough to power all of the gear)

2) put the adapter plate in place (should be delivered very shortly) fix the cables along the pier and install the proper electric plugs etc at the top of the pier. 

Getting there! 

1 hour ago, Macavity said:

You can always "jiggle it a bit"! (Or leave it well alone?) 😁
If it fails to bond, you can DRILL the blocks and add bolts?

It may "kill" a standard drill, but I was surprised how easy it
was to drill (at least) standard concrete blocks! 😉

Yeps, that was my thought, metal plates on the sides and drill it essentially as a belt. It proved so easy to go through that I may do it just because. 

Just now, CraigT82 said:

Looking good, I wouldn’t worry about trying to dampen the pier from your footsteps, just don’t go near it once you’ve started the imaging run, or pause the run if you do need to go near it. Some longer cables to get the laptop a bit further from the mount will be good. 

Actually it's all piloted from inside the house in the comfort of my office with multiple screens etc 😇 I love the geek feeling 😅