FrenchyArnaud

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. stellarium 2023 02 07 19 33 26 67.mp4

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 : WhatsApp Video 2023-02-07 at 19.20.54.mp4

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!

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!

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.

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

Ok, I can't help but share with you this preview... The blocks are glued with CT1 (brand C-Tec) and the local jewson's reliably informs me that after 24H it will be easier to break the blocks than to unbond them. I hope it is true. The mount is actually screwed on as I drilled the block BEFORE installing it (I was unsure how hard it would be) Drilling the main axis was not especially difficult but drilling at the right place was. So I drilled 3 times on 2 blocks before one of the centering was correct - this centering now sits on top of the column. Drilling the brake disc holders will be much easier because I will just clamp the disc in place and use it as a guide. Of course this is just a temporary fixing for the sake of the picture, the mount will be put on a proper adapter. So now I am only waiting for the brake disc to be delivered 😇 The GF is hunting for the correct colour of concrete paint to match the fences and is looking into hanging small flower pots to decorate the column; I will supervise the weight distribution but I am confident it should be ok. The thing is solid as a rock - litterally.

Yes I could have done that but I read your idea AFTER I poured, plus, it woukd have added too many steps for my taste (even though objectively that would have been better) I keep the idea though because if it turns out I can detect foot steps on the guiding graph, I think I can dislodge the adjascent tiles, cut the slab base underneath the middle of the tiles and fill this fracture line with sand or sthg, in effect isolating the square where the pier is and the ones directly around it from the rest of the walking zone, while still having the benefit of a 3x3 tiles surface to fight gravity sinking of the foundation. I'll do it if it proves needed.

Ok, Day 2! Went to Jewsons, bought all I needed : 5bags of quick concrete "postfix", 4 hollow blocks and masonery glue. Because my garden is accessible only from behind/around the house, I had to carry all of it around and that's no fun. Fortunately I was able to recruit my trusty assistant Mocha for help. Well, for moral support at least; well, he has a knack for being exactly where it is the most irritating but hey ho, he's trying. That must count for something. I threw a couple of liters of gravel stolen from the flower bed at the bottom to provide a support for the first block, which will act as my anchor. That allowed me to present this first block/anchor and set it stable and, after a lot of fiddling and jiggling, to get it nicely aligned and level. This Postfix aka Blue Circle aka Postcrete does not require mixing. The way it works, you fill the hole 1/3 to 1/2 with clear water, pour the dry mix on top of it, paddle with a stick to eliminate bubbles (and in my case, make sure the mix gets inside the lower hollow), until the water surface is reached, and repeat until you are at the desired level, at which point you just cover the top of the mix, still dry, with more water. You have 5 to ten minutes for the whole operation so you really want to make sure you have everything at hand. After 15minutes it is mostly set and pretty much impossible to move. I dedicated 2 minutes half way through to making sure the block had not moved and was still perfectly level. Once you reach top level you can, if you wish, smooth the surface - I did not bother. Here is the result. Because I added tons of water, it took about 1 hour to really set, but right now, about 2 hours in, it is pretty much rock hard. I will not try to walk there or do more out of precaution but I am confident I could stand on the block and it would not break a sweat. Only I did. That's some serious exercise for old me. Next stage: glueing the 3 other blocks on the anchor - that at least in theory should be child's play as my support is dead level and rock solid.

I am a bit puzzled here. Why do you need eithet? the pds are already adapted to get prime focus (shorter tube than the P)

I tell you what, I have spent 2hours asking myself exactly that when I realized I needed a new plan. It is actually 2 questions: is it needed? How to do it? I could not decide if it was needed but i sure as **** was not able to come up with simple way to do it, so I decided that no there will be no dampener. The downside is, I will need to avoid walking there during sessions but I usually don't anyway. I just wonder if the temperature change will make the tiles oscillate 😞

Thread pursued here :

Hi guys, so, following the thread here: I have begun the construction of the pier. I am opening this thread to document the progression; as I have been reading countless threads and watched countless videos before begining, I assume this will, at some point, be of interest to someone (and allow me to keep track as well) So, for starters, the quick photoshop of what the GF agreed to: I understand it's a classic design called a Tordmorden Pier. That was the original plan but it went south from the get-go. My idea was to screw/glue the bottom brick to the tile, which is solid and encased on a concrete slate, avoiding the need to build a foundation. However! Just for peace of mind I probed, pried the tile with a crowbar... And it popped right out without any resistance. The material underneath felt and sounded like concrete indeed, but I was able to mark it with the crowbar, and it turned out to be some sort of hard, but brittle grout. So I drilled into it to have a better feel of what I was facing and the drill went rigt through it in seconds. Totally unsuitable to rest the pier... So, plan B. I need a foundation and for that, no two ways about it, I need to cut away this slate of whatever it is and dig underneath it. Brittle but pretty sturdy and a good 3" thick, I tried brute force but no way. So I did the obvious: drilled all around to cut it.. . From there I was able to fracture it with the crow bar and pry this part of the slate open without disturbing the other tiles. (GF would NOT have been impressed!) From there is has been much more straight forward but back breaking: break the ground with the crow bar, dig out, rince, repeat. I am now left with a neat 1.5ft * 1.5ft * 1.5ft deep hole where there once was the tile. I cannot go deeper as I have hit what looks like either the bed rock or a massive boulder. Either ways, I am confident this will be ok. The plan is to fill it with concrete with one of the hollow bricks 3/4 submerged in it, exposing only the side surface (21cm*21cm) about 1" above the level of the adjacent tiles. And this, will be my foundation... Half way through digging: Next stage : pouring concrete and inserting the underground block to create the leveled anchor plane the rest will be glued on To be followed!

Yes. My reasoning is that I can drill bang central of the very top, use a long bolt with a washer from inside the last hollow, so by conception it's the most simple with the least parts and alignment errors possible. Also, rapid maths tell me that the whole assembly can be just under 100kg, so, considering it will be centered on the tile and, by definition, perfectly balanced, there will also be the least stress on the cement underneath. A poured pillar would weight several times that and potentially could fracture the cement underneath. So to me, this has the merit of a ridiculously low cost (in the region of £50 all inclusive), a light structure, easy to design / align / realise, and likely durable because the thing would not put more stress than me just standing there. EDIT : and no need to break the tile, dig a hole, mix and pour concrete, cut rebars etc... because no reinforced foundation is needed.

So after a lot of debate, I settled on a pillar made of 3 concrete hollow blocks, possibly 4. These tiles are on a concrete base so I am thinking, drilling-screwing-glueing the bottom one, glueing above that with one big bolt in between the blocks, one brake disc on to suspended by M10s to be able to set perfect level. Quick and dirty photoshop to show the GF what she agreed to (the telescope here is facing east but it's unimportant)

Check DMs 👍

Ok I am officially jaleous 😇 That is top notch!

Do you have a link? I can't seem to find it.

Not sure what older thread you nean but I will forage the forums Duly noted 😅 Sorry, I am french - been 10years in the uk but sometimes I come up short 😅 Nothing is done, it's ground zero for now. I did not want to do anything before I have a completely defined plan for everything. I know how and where to do the foundation and the column, insert threaded studs etc, and make an electric box to set everything safe. I struggle purely on the assembly concrete column / mount. But at this point I already have a much better global vision of this part too, thanks to you guys 👍 Nice set up, by the way, very neat!

Good to know!

Actually this multi fit one looks like a nice option and lists the cg5 as compatible ! great find 😃👍