LuckieEddie

I had a minor issue this evening that with hindsight was a good thing. While testing the manual rotation control I slipped with the multimeter probes causing a temporary short. This blew the protective fuse on my OCS4 controller. While hunting for my box of fuses it occurred to me that the manual control 12V supply should not be connected to the fused OCS4 12V. This means I need to add an additional fuse in the control panel and wire it direct to the PSU. Lucky I found it now during testing rather than later on when in operation. Even with no faults I would have been overloading the current fuse slightly so it would have blown at some point.

Today I peeled the pier (removed the cardboard tube former) and also removed the wooden support frame. Quiet a few 'bug holes' but nothing too large, at most maybe 5mm deep. While the surface was still damp I gave it a 'bag rub with mortar. A reasonable start but more finishing definitely needed. After that I've started positioning and wiring up the power supplies (12V for the doors and squome, 24V for the mount) and control system. I'm using an OCS4 as the controller, an open source project by Howard Dutton, the author of OnStep. I've also made a manual control panel for overriding the system if anything goes wrong. All cases were 3D printed.

Surprisingly it only took about 4 hours but this morning my back is reminding me that it wasn't a gentle 4 hours.

Yeah, I know. I meant 12 noon UTC. I've only eyeballed it though so it won't be that accurate. I do have +/- 1deg adjustment possible on the adaptor plate and my mount has about +/- 10deg so I don't think it'll be a problem.

Pier concreting day. Here's the prepared workspace. Pile cage mounting on a wood surround. I've used ⌀68mm drainpipe for the cable conduit up the centre, held in place with galvanised wire for concreting. I've strapped two spirit levels to the pile cage so I can keep an eye on the level and tweak as I pour. Concrete just below the tube mount level. Removed the pile cage support ready to install the tube former. Tube former installed, spirit levels remounted on the tube, and tube base temporarily back filled to help hold in place. Looking down the tube former ready to start bucketing concrete in the top. Pouring finished, studs for fixing the the pier adaptor are held in position by a pair of wooden alignment boards, which also centred up on the sides of the tube and had a North alignment marked to match up with the line I'd previously drawn up the wall from a 12 noon shadow. Thanks and hugs to Debbie for helping with the concrete spade work, filling buckets while I lugged them up the ladder, and keeping me hydrated.

The cardboard tube concrete former for the pier was delivered yesterday, and I collected the rebar pile cage today (thanks again to Nick, this time with his trailer). Tube is ⌀300mm internal diameter x 2m long, and the pile cage is ⌀200mm diameter x 3m long. The tube may need trimming down a bit - I'll find out when I do a test fit.

After I made some fine adjustments to the wiring of the roof sequencer, ie. using the correct connector positions (RTFM Ed, don't assume), we have lift off! First opening/closing sequence... VID_20240812_182110774.mp4 It's about 45 seconds for both doors to open or close. A bit noisier than I was hoping/expecting but there's no insulation in the doors yet which should dampen it down a bit.

Yep, I thought of that one. On the lowest edge I've drilled drain holes through the wrap over end pieces and sealed the joint internally with silicone. We had a little bit of rain this week and it seemed to drain okay. Typical isn't it, when the roof was off, and then done but with the hole it never stopped bucketing it down. Since I've put on the 'dome' (which I'm now informed by the wife should be called a squome [for square dome]) it's only lightly sprinkled once!

Thanks Alan. Door motorisation coming soon. I'll be happy to show round once it's a bit more finished.

Today I've trimmed the plastic cladding flush so that the aluminium frame of the doors sits flat on the aluminium frame of the base. I've also fitted a rubber seal in the upward facing extrusion on the hinge side with a flat plastic mating insert in the facing door extrusion. Then along the sides where the doors close I've fitted a raised V-section that acts as an alignment as the doors close and also a water break. This was a piece that I designed and 3D printed. Now onto the door motors...

Yep, there's an upright section of the lining ring that was fibre-glassed along with the rest of the roof that overlaps about 30mm with the 'dome' base cladding, and the edge of the cladding is also raised 20mm from the roof. So unless the rain can splash vertically more than a couple of inches underneath the overhang of the base I should hopefully stay dry. 🤞 You can see the ring in the photo I posted earlier in the thread on the 19th July.

Use it or lose (more of) it. I always have some sort of project on the go, it's not good for me to leave my brain in neutral.

The pattern on the first image is a de-Bayer artifact. It looks as though you used an OSC script to process the data. I prefer to use Siril in manual mode. Although it's very old and the UI has changed a bit, the tutorial that helped me understand most about using Siril was this one: https://pixls.us/articles/processing-a-nightscape-in-siril/. When you get to the "Demosaicing the files" section you need to change step 2 ie. Make sure that the debayer check box is unticked.

Really good progress this weekend. Saturday morning I finished cladding the base of the 'dome' and with help from Nick got it up and mounting on the roof. Then I spent the rest of Saturday and Sunday morning cladding both the doors. This afternoon, again with Nicks help, the doors were fitted to the 'dome' base and I'm now watertight (in theory). Manual rotation works well with everything looking level and the centring castors appear to work. I've got a little bit of plastic cladding trimming to do in order to get the fit perfect between the doors and the base.

Earlier in the week I also prepared the aluminium framework for the 'dome' cutting 1.3deg angles on the uprights (to create a drainage drop) and milling the holes for the joining pieces. Thanks to Justin for the time on the mill. While I was waiting for each coat of Plasti Dip to dry I was able to screw together all the framework, base and doors. I temporarily fitted the hinges to test the fit of the whole assembly. Looking good... I've since separated the doors from the body ready for fitting the body frame to the plywood base.

I've just finished the third coat on the base. I've used a product called Plasti Dip. This will permanently waterproof the plywood and has the advantage that when dry it still has a slightly tacky surface which will help the drive gear grip. It often used for things like dipping the handles of small tools, like pliers, cutters etc so it's that hard rubber/soft plastic finish.

Yesterday evening I took the 4 sheets of 12mm plywood that I'd cut earlier in the week and glued them together to form the base of 'dome'. Lots of PVA and 20mm screws. This was left to dry overnight. This morning I marked the centre and drilled it. I then screwed a length of thin plywood to the bottom of my router and nailed a pivot through that and the centre of the base in order to cut out the 2m circle. Thankfully this went to plan. Also another success was that I'd measured correctly and I could fit this cut base out through the observatory doors. This gave me access to plane the base down to the final size. and sand the joints smooth. I then bought it back in to paint.

I'm occluded to the north, north-west, south-west and south by houses. There's a screenshot from Google maps near the top of this thread. Where I've been setting up on the patio using a Losmandy HD tripod the houses were blocking up to approx 30 degrees. When the observatory is complete I'm putting in a taller than usual pier to go with the higher than usual ceiling. This additional height will lower the blocked areas to approx 20 degrees. This is another reason why I choose to go tall. The worst offender is still my own house, being the closest. Oh and one palm tree that''s really close to the south.

The 'dome' is another unusual aspect of the build. I decided early on that I didn't want it to be cramped inside my observatory, therefore I wanted a ceiling height that allows me to stand upright. Luckily I'm only 5'6" so I was able to go for a 2m ceiling height. However, with the location of the observatory being very close to my property boundary I'm limited to a total maximum height of 2.5m to fall within planning regulations. So I needed a 'dome' design that has a diameter of 2m but a closed height of only 500mm. The solution I've come up with is to have a pair of doors that hinge open mounted on a square body that rotates. It's a dome in function only, not form, hence the quotes around 'dome'. My plan looks like this... The frame of both the body and the doors is made of 4040 Aluminium extrusion. The base with the circular hole runs on castors, is driven to provide the rotation, and is made of plywood. The outer skin of the whole 'dome' is uPVC cladding. The first 'dome' construction job is cutting the ply sheets to laminate together for the base.

The fixed mains electrics are now in, including a pair of RGB dimmable LED flood lamps so I can set them to dim red when needed. Next up, the 'dome'.

More good progress today, insulation fitted under the roof and inner skin fixed up. Next up, finishing the mains electrics - now it's no longer raining inside the observatory.

I can print your radius block if you want. I'd suggest using ASA rather than ABS for the UV resistance (ABS can become brittle after a while). Personally I wouldn't typically recommend printed parts for anything load bearing though. If you want to proceed, pm me.

Today the roof was fibreglassed. As I had free choice for the colour, I went for white as I thought that should give me maximum reflection/least solar heating. We're in an urban location so it doesn't need to blend in with anything (although next doors' shed is white plastic as well). Next up is fitting insulation under the roof and an inner skin/ceiling.

It's taken an age but I've finally got the roof structure and skin up. I've felt like Noah over the past few weeks with the amount of rain I've had in the shed observatory. I've also been delayed by a horrible cough that I can't shake (and have passed round the family). Here's the roof from the inside. The big beams making up a hexagon in the foreground are the supports for the "dome". The skin of the roof is OSB that's going to be fibre-glassed.

Late to the game, but here's my attempt on the data using only StarTools.