Moonshane

I had a similar issue but could always see a reasonable amount of detail which was improved by changing the ITF as above. Not the end of the world and it's a consumable item (although the Meier one is a lot longer lived I understand).

This is one reason I have never thought about selling my 1/10PV 6" f11 even though I hardly every use it now I have the 120mm Equinox. It's not worth much and is a great option to have.

One of Saturday's planned 20+ obs jobs is to make the frames for the three roof panels. Having used an impact driver last weekend (borrowed from Ken) I could not really face the idea without one this weekend and one now forms part of my project costs! A cheapish 18v but with two batteries should be good enough for my purposes https://www.screwfix.com/p/mac-allister-msid18-li-18v-1-5ah-li-ion-cordless-impact-driver/220fx Jobs planned include paint frames all round with black paint, create concrete pier, fit roof panels, make door, fit breathable membrane all round, fit roof finishing sheets and all the various bits that go with it! If I get half done, I'll be pretty happy.

Really well written Stu - I felt I was there with you! 🙂 Looking forward to gazing again once my obs is operational. Might be sort of usable with a dob by Sunday (albeit not finished).

Yes sorry Dave I didn't think you meant erect image prisms. They are a bit more variable and (I believe) can sometimes result in star spikes at night.

I have never noticed a difference and use the same prism as John in my 120mm Equinox and my 100mm pst mod. My main reason is not optical quality but the ability to shorten the light path for binoviewers and the pst mod. It always looks good in monocular vision too although there's a minor amount of vignetting with my 27mm Panoptic. Buy quality either way and I don't think you can lose.

Picked up my 250mm diameter galvanized tube today. Here's a pic. Naturally it needs cutting down and filling but the size is great. Here's the roofing materials. Too.

Great thread telling if overcoming lighting adversity 👍 Your thoughts echoed my own re lights. I got so fed up of idiots leaving lights on all night I almost stopped too. Getting my mojo back a bit now with my own build ☺

Fab start. I am slightly further on but the same size and simpler as I am visual only and want to have several scopes available. E.g 120mm Equinox on my pier and 16"dob at the side ☺ The insulation will certainly keep the wind out 👍

I have come up with a better solution in my head overnight. More to follow soon but will be a three section roof with the top a simple hinge to rear, the front will pivot forward as before. The middle section will be a mini ROR which will roll either to the front or the back of the structure depending upon where I am observing or to allow alignment. I'd imagine it will be mostly put to the back. This reduces lifting weight and increases flexibility. I know a standard ROR would be simpler but I think this matches my requirements better and will be rather unique.

Oh blimey. Having checked the half fixed roof idea, I am not keen. It feels really restricted. I am now working on my original plan of a folding roof at the back.

Mine's the opposite. I'll be solely visual so this is why I have been agonising over the design. Naturally you could 'over-engineer' and if your design can effectively ignore weight this is fine and dandy. I didn't really want the stands associated with a ROR as I like my gardening too!

LOL. They were all straight...........eventually.......... 😂

I used 6x2 tanalised for the floor joists and 3x2 scant for the rest. I am trying to keep weight and cost down and for the roof, a 4m span with 3x2s will sag especially if there's snow resting on it. Therefore I'll be installing two removable 'purlins' from the back to the front, and touching the underside of the roof panes to provide support. These will be taken out when in use (and I may actually use them to prop the rear section while dropping the front - I like multi purpose!!). Good luck with your build!

I'm fitting an external male caravan connection to sockets inside my obs. Like this I'll then connect to an external socket in the garden which is already there with a female connector and a standard plug. That way I can have power when I need it but it's cut off when I don't. The wire will be removed when not observing or using the building.

Fair comment but the light pollution is terrible to the north (Manchester) - it literally lights the sky - and trees/my hedge virtually block the whole vista (self imposed as houses are being built to the north too.). The Beech hedge to the rear will be left to grow higher still, albeit I'll be doing a rejuvination prune to take the sides back about two feet from the obs over the winter.

I had a ‘design meeting’ with Ken last night and we concluded that as I am not really likely to be looking ‘back’ towards north with the scopes, we could have a more simple roof design. The one proviso is, of course, the need to polar align. Therefore we will have a single, larger hinged rear section (hinged as it needs to be raised slightly as the top roofing sheets will obviously overlap the bottom ones). The front section will also be slightly larger but more or less as previously. This should help with both setting up and also shielding from light pollution. I had a sit in the structure with binoculars last night and even though it is open framework, I can really see that it will make a huge difference. As I look up a 25% incline to the house, I may need a couple of removable sheets of ply to mask the lights every now and again but only when observing at certain angles. Before weekend I hope to pour the concrete pillar and then paint the structure, but first I need to temporarily fix my mount to the current steel inner support and see where Polaris is in relation to the roof so I can establish the roof section dimensions. Then this weekend we can hopefully create the roof. Setting out my thoughts like this will hopefully help others in their own designs, although my circumstances are quite unusual I suppose!

I made some progress in my head at least last night - I couldn't sleep thinking about the issue of counterweights and making the opening and closing of the roof less 'exciting'. I went from spring systems (like a garage door) to winches (silent work gear ones (I think they would take far too long) and finally to 'block and tackle' type rope hoists. The latter is the system I will use. This has the advantage of being light, strong and variable enough to cope with the roof design I have in mind. I'll send photos as always once I have got the thing sorted. Next step will be to pour the concrete post and set the pier top in position (assuming I can get a sunny period at solar transit time on Saturday or Sunday. Then create the roof sections and fit into position. I am hoping that by Sunday I will have the basis of a usable obs bar the cladding which I'l order once I get the roof done. As always I would find this all a much slower process without my Mr Miyagi, father in law Ken. I will never underestimate the volume required of screws and timber, nor the benefits of an impact driver, again. Another thing mentioned by Ken, that I had not even considered 😊 was the possibility of snow on a roof of 4x2.4m dimensions and constructed of 3x2 timber. Whilst to keep weight down, we'll still be using 3x2 for the roof panels, we will install two removable purlins in the form of 2x 3x2s screwed together.

I have an 8" ID card tube to create the pier around the current steel probably a little higher than currently. This would need to be removed after setting. Thatsaid I can also get as a favour a 10" ID galvanized steel spiral duct which could be left in situ and painted. I think I might go for the latter. Ran out of timber more or less for now. Use 135 linear metres! Need maybe another 50 at least. The decking was left over from our old deck so free effectively. Total cost so far About £500. I reckon about £800 total.

Progress! I have walls and a floor!

I am thinking more along the lines of nothing (50kg is not really much weight and most will be taken by the pivot axis pins (4 as I will have two arms per side)). That said, if required I am investigating the use of garage door springs and wire. I generally adopt a suck it and see approach to design and build. Usually things work out. 😉

My design hopefully (albeit with a flat roof not a pitched roof), will be a combination of and

Well this weekend I hope to get the floor joists, main frame and roof framework done. I’ll be putting the concrete pier in after the floor joists are formed as this will make assessing the final height a bit easier. I’ll show how these bits fit together in due course. The roof will be flat but in three sections, all 1m deep by 4m wide. I envisage each leaf will weigh about 50kg. I may develop a spring or counterweight system depending on the motion. The obs will only really open up to about half of the sky looking south (but uphill) as Manchester and Ashton-under-Lyne are to the north. There will be plenty of objects to keep me going, especially as I should be able to maintain dark adaptation! The front section will be on a pivot and the two rear sections will be hinged/concertinaed. That said, I expect that on most occasions I’ll not have to move the rear sections other than to lift slightly to allow the front to pivot. I’ll take some pics as I get to various stages over the weekend.

I agree that like many things experience counts. I suppose technically you are training your brain to see differences in the background sky that are the fuzzies or clusters etc, not your eyes. The techniques mentioned above are important to this as is keeping out of as much light as you can - even a red torch can affect dark adaptation. Be careful though. I was once observing the Pacman nebula at a star party and had been for a while. It was in field and someone passing asked if they could have a look. On viewing the field he said "I think I see what you mean but cannot tell if I am seeing it or remembering it" 😁 For this reason I always try to sketch the field and shape of the object before looking at images. This way you can check if what you think you see is the target object. As a side benefit, sketching seems to allow more focused observing and helps see more detail in most objects, even bright ones (like the solar system objects).

Yep you'll be delighted. Just enjoy it!