Gina's Observatory

[Pete Presland]

coming along nicely

[Gina]

Thank you

A bit more done today - 4 of the joists screwed down at the warm room end (west) and the struts cut and placed in the obsy south wall. Very cold early this morning with a chilly wind then this afternoon the showers started and got heavier and more frequent as the day went on.

I've also been working on the other thread, devoted to the build, adding many more photos with explanations. Once I get up to date I shall continue the build info over there.

[Gina]

Very wet today so doing indoor jobs. May get some sawing done this afternoon.

[fwm891]

Looking great on the webcam Gina

One small thing - The asymmetric rails are the wrong height for gymnastics !

[Gina]

Looking great on the webcam Gina

Thank you Too wet and dull to do much today but I did cut six more joists as you can see on the webcam.

BTW - I've set the scheduler to stop uploading at 7pm so that the end-of-day image is retained overnight. Uploading resumes at 7am. It's unlikely that I'd be doing anything before 7am

One small thing - The asymmetric rails are the wrong height for gymnastics !

Too far apart as well

[JamesF]

Very wet today so doing indoor jobs. May get some sawing done this afternoon.

It's been hideous today, hasn't it? I've been trying to finish the construction of our new airing cupboard which meant cutting 8x4 boards for the walls -- easier and cleaner to do outside. I've been dodging the showers to make a single saw-cut and then get back inside before it started raining again

James

[Gina]

It's been hideous today, hasn't it? I've been trying to finish the construction of our new airing cupboard which meant cutting 8x4 boards for the walls -- easier and cleaner to do outside. I've been dodging the showers to make a single saw-cut and then get back inside before it started raining again

James

Ah yes - quite! Horrible!

[Gina]

Another day of dreadful weather so no build progress. However, I've been looking at the design again having assessed the practicalities and come up with a possible modification which would reduce the amount of work involved. The idea comes from looking at Tim's (TJ) obsy build where my roof design is similar to his and the north side of my design has the roll off rail at a similar height to his. So thank you Tim for the idea

Instead of having the north side warm room wall set inside the roll off rail I could set the rail on top of the warm room wall (well, most of the wall). The rain that falls on the warm room side above the rail would not be much and it won't hurt for it to run onto the rail. It means that the obsy and warm room north walls can be all in one, saving timber and the complexity of joining the two walls below the rail. The screenshot of the SketchUp model attached should make this clearer.

I have yet to sort out the precise details of the top of the wall and the warm room roof but I don't envisage too much trouble.

[yesyes]

Looks like one of your goats is fed up with the lush grass and prefers foil now...

[Gina]

Looks like one of your goats is fed up with the lush grass and prefers foil now...

That's our young billy goat - he nibbles anything! That's bubble wrap actually, that I use to protect the tarp from the sharp corners of the woodwork.

[yesyes]

Well, you gotta try everything at last once... The challenge is remembering what you have already tried...

[Gina]

Well, you gotta try everything at last once... The challenge is remembering what you have already tried...

Yers

A previous billy of ours ate a 10" length of chain and a 4" nail and who knows what else

[Gina]

I'm having second thoughts about the roll off roof (or is it 3rd, 4th, 5th.... thoughts ). There are a couple of big disadvantages of the joists, OSB, felt system. Primarily the weight but also I'm not sure how well the felt would stand up to the twisting and bending of a roll off roof (as brought up in another thread). I'm thinking of looking again at corrugated bitumen sheets. These would be lighter than OSB plus felt and if I went for an apex roof to give sufficient slope, it would also mean a more rigid structure than a flat roof.

My earlier thoughts on this were to have the ridge running parallel to the longest dimension of the complete structure but now it looks like having the gable ends on top of the RO runners would be better. Rainwater from the western slope could run onto the warm room roof as in the present design. The other slope could have its own gutter over the end wall, attached to the roof, or it could be extended further out and do without guttering (as in many sheds and other obsy builds). I think I favour guttering though.

I'll post the new design when I've finished modelling it in SketchUp. It will not affect what I've already built and I'm thinking of keeping the warm room design the same, with a pent roof of OSB and felt. The weight of the warm room roof is of less concern as it will be fixed and the support structure is very strong. This part is almost complete and consists of 3x2 uprights, about 19" apart, with 3x2 pieces on top and will later have 3x2 roof joists.

[laser_jock99]

I'm having second thoughts about the roll off roof (or is it 3rd, 4th, 5th.... thoughts ). There are a couple of big disadvantages of the joists, OSB, felt system. Primarily the weight but also I'm not sure how well the felt would stand up to the twisting and bending of a roll off roof (as brought up in another thread). I'm thinking of looking again at corrugated bitumen sheets. These would be lighter than OSB plus felt and if I went for an apex roof to give sufficient slope, it would also mean a more rigid structure than a flat roof.

My earlier thoughts on this were to have the ridge running parallel to the longest dimension of the complete structure but now it looks like having the gable ends on top of the RO runners would be better. Rainwater from the western slope could run onto the warm room roof as in the present design. The other slope could have its own gutter over the end wall, attached to the roof, or it could be extended further out and do without guttering (as in many sheds and other obsy builds). I think I favour guttering though.

I'll post the new design when I've finished modelling it in SketchUp. It will not affect what I've already built and I'm thinking of keeping the warm room design the same, with a pent roof of OSB and felt. The weight of the warm room roof is of less concern as it will be fixed and the support structure is very strong. This part is almost complete and consists of 3x2 uprights, about 19" apart, with 3x2 pieces on top and will later have 3x2 roof joists.

I pondered a long time about having a lower southern wall like yours but the complexity of roofing it put me off. In reality having a tall pier gives me reasonable horizon views anyway. I just can't ever use a Newtonian in there!

[Anweniel]

You have more details on the bitumen sheets? I work in a civil engineering laboratory and as such do a lot of work with bituminous products, to be sure of a good waterproofing and longevity I would be VERY cautious of the quality of the bitumen coating.

Susceptibilty to UV, heat is my biggest worry. Make sure you research thoroughly (not that I doubt you wouldnt )

Was looking forward to catching up on your progress but the cam is down Looking good so far though

[Gina]

You have more details on the bitumen sheets? I work in a civil engineering laboratory and as such do a lot of work with bituminous products, to be sure of a good waterproofing and longevity I would be VERY cautious of the quality of the bitumen coating.

Susceptibilty to UV, heat is my biggest worry. Make sure you research thoroughly (not that I doubt you wouldnt )

We've used the Wickes stuff and found it alright.

Was looking forward to catching up on your progress but the cam is down Looking good so far though

Actually if the cam was working all you'd see is a shed shaped blue tarp Too damp today to remove it! Today I replaced the computer that was running the webcam and uploading the images, with another one - the one I was using some months ago before it went wrong. It is more powerful with more memory, faster processor and bigger HD. I had forgotten that I had it set to upload a preselected image when FTP upload was scheduled to finish at 7pm. I'll change that tomorrow. Normal FTP upload resumes at 7am anyway.

Quite thick fog here now Complete change in the weather is forecast for tomorrow. I wonder1

[Gina]

I haven't completed the modelling but this should give an idea of what I have in mind :-

[Anweniel]

We've used the Wickes stuff and found it alright

Aye always better to rely on experience, not skimming costs on unfamiliar products:)

We've been having a bit of an Indian Summer here in the Midlands and somebody far away has bought a new scope/cloud magnet as we have clear skies for once!

[Ransu]

Very smart and interesting structure Gina, well done

Nice to see your obsy growing up from ground. I think now that my observatory has been so far my best investment in astro hobby. It's very easy to start take images or just observe when everything is ready, just waiting to open the roof:)

[Gina]

Very smart and interesting structure Gina, well done

Nice to see your obsy growing up from ground. I think now that my observatory has been so far my best investment in astro hobby. It's very easy to start take images or just observe when everything is ready, just waiting to open the roof:)

Thank you

Yes, I'm very much looking forward to just popping out, opening the roof and getting going - in fact I can hardly wait!! I went out after dark last night and stood on my obsy floor and looked out and up at clear skies with millions of stars and one very bright object which I assume is Jupiter. I want to get my scope on that ASAP But I shall have to be patient a bit longer. But the future looks great!

[pritc]

Gina,

Get your goat to hold the screws for you.......

Wayne

[Gina]

:D Ha ha ha :D

[Gina]

Been looking into the "trolley" and running track as I'm at that stage of the build.

Had planned to use a wooden strip along the inside of each rail - 22mm high... BUT the tyres on the wheels I've got are only about half an inch thick (12mm) and the steel rim rubs on the wood. This doesn't seem very good for easy running! So I'm looking at possible alternatives. I'm not happy with 12mm wooden strips - I think the wheels might ride up on rough (or even planed) wood. So maybe it's coming down to aluminium again (one of several options).

Also, I think applying the guiding to just the higher rail would be best as the roof height above that is relatively small and the structure should be quite rigid. As long as the upper (north) side is well guided, the lower side should be fine with the 100mm rubber tyred wheels (with 25mm wide tyres) running on a 75mm wide wooden rail.

ld

Now then... options for quiding :-

1. The deluxe option - gate rollers and track. I like this idea but my bank balance doesn't! and it'll take longer to save up the money. Thank you to Helen for the info

2. Aluminium channel. Maybe with solid nylon wheels - with a low side wall rubber tyres might still ride up.

3. Sideways acting rollers/casters. Small, lightweight ones would be quite adequate. A total of 4 should suffice. Each side, at each end.

[ncjunk]

I did it with wooden slats for channels with the wheels on the wooden structure. I would not advise doing this as the weight of the roof going over the wood is causing the wood to split, then the rain gets in and it gets worse. The wooden slats rub against the side of the wheel but i fixed this by putting a couple of small guiding wheels on the roof to make sure the wheels stay marginally away from the slats.

I am now doing what i should have done in the first place which is putting down angle iron but keeping the guide wheels on the side to, again, ensure the wheels dont rub.

The wheels are 75mm diameter nylon?? With a load capacity, i think, of 50kg each.

So i would say put something down for the wheels to run on.

[Gina]

Actually, Helen's deluxe option is not really all that expensive unless you go for stainless steel track. If I were to use this for the higher track only and keep to rubber tyred wheels and wood for the lower one, I could use a 6m length (3m isn't enough) of galvanised track at £29.20 (ex VAT) and two wheels at £9 each (ex VAT). That comes to £56.64 inc VAT plus carriage. With 2 wheels with flat mounting the problem of getting an exact height is avoided.