For a while I've been interested in setting up an observatory, as like most I'm not too fond of setting the gear every night for a session. I had considered various alternatives:
an outdoor pier and mount covered when not in use
cutting a hole in the garage roof
cutting a hole through the upstairs roof
Whilst upstairs assessing the work associated with cutting a hole in the upstairs metal deck roof, a much easier solution dawned on me: rework an existing skylight that I had built as part of a previous (still unfinished renovation).
We have an old (~1900) single storey Federation home and probably about 10 years ago we added a modern light/open 2 storey renovation, but didn't build the new 2-storey structure any higher than the existing single storey roof line to maintain street front appearance. This was possible thanks to some very high ceilings in the old section of the house. Anyway.... what this meant is that the 2nd storey floor (in the new section) was actually about 600mm below the existing ceiling level in the old part of the house. So what did I do? I cut a small access door through the 2nd floor wall to allow me to get in to the roof space in the old section to use it for storage. I also added a small ~0.9m square opening skylight in the tile roof for natural light and roof service. After a while the small access door in the wall grew in to a full height and very wide doorway and attic passage linking the 2nd storey of the new addition to the Roof/ Attic space of old section of the house. This attic passage was full height (~3m) with an overhead essentially flat large glass skylight above (~1.5m x 1.8m).
The observatory will be built on an elevated/suspended floor somehow within the attic entrance (shown in the images below) and isolated from the pier/mount. (Not as ideal as say a large concrete block in the earth in a ground level observatory, but you work with what you have. )
Attic Entrance Passage
Attic Entrance Passage
This skylight is situated 3m above the floor of the attic Entrance Passage and is approximately 1.5m x 1.8m in size. It is 3m above 2nd floor level and approximately 7.5m above natural ground level. The elevation will certainly help somewhat in blocking out lights from the neighbors and help with ground level temperature gradients. The skylight will be removed and replaced with a roll of roof which will roll 1.5m towards the NW side.
Through the glass you can see the top ridge dragon of the terracotta roof. This marks the limit of the NE views to no less than about 25-30 degrees. This is more than OK by me and shields the light from Nepean Highway very close by. As an aside the Artificial brightness Level at our home according lightpollutionmap.info using the World Atlas 2015 data is ~2960 µcd/m^2 which is ~17times brighter than the natural sky brightness at a Dark Site or around SQM = 18.84 mag./arc sec^2 (not too good)
View in SW direction. The Glass Skylight (LEFT SIDE of the image) is to be replaced with a roll off roof. The smaller Perspex Skylight/Opening Roof Hatch (RIGHT SIDE of the image) will remain.
The South westerly Sky viewed through smaller perspex skylight.
View in SW direction. The Glass Skylight (LEFT SIDE of the image) is to be replaced with a roll off roof. The smaller Perspex Skylight/Opening Roof Hatch (RIGHT SIDE of the image) will remain. Attachment 271303
The South westerly Sky viewed through smaller perspex skylight. Attachment 271304
6-12 months ????
Best
JA
Buy yourself an exercise book.
Rule up pages to have columns.
A column for each of...Job, time required, night or day job, cost, materials.
So a line may show...
Job. Trim widget...time 30 mins...can be done at night...cost $10..materials wet and dry abrasive paper.
The idea is you can look in your book and select a job that takes in this case 30 minutes and done at night, see that you have or don't have materials...that day as you can spare ten bucks and going to Bunnings anyways you buy the material and do the lob that night because you know you will have a spare 30 minutes...
Or finding yourself bored with nothing to do you flick thru and select a job that fits the time window and the materials are in the garage.
My point is carrying plans in one's head let's you miss opportunity to select and do jobs...the idea is each day you can look and see what to do if you have the materials and what they cost...
I have managed many projects this way...you do many small jobs and can check before shopping to buy small cost items...it works.
Hi JA,
I’ll be following your progress with interest. If you want to keep the skylight for daytime use, you could consider a sliding skylight...
Thanks AA,
I had considered EXACTLY that as the existing skylight is made from 8 or 10mm laminated glass for fall safety. I might reuse it and although it would add 60-70kg to the roof that wouldn't be an issue with an appropriate steel frame and rollers.
My point is carrying plans in one's head let's you miss opportunity to select and do jobs...the idea is each day you can look and see what to do if you have the materials and what they cost...
Yes: good point Alex.
Seeing a list is important for prioritizing multiple projects with many competing activities. It's also a good motivator when tasks get crossed off.
That's almost exactly what I already have with the smaller skylight an ~0.9m square opening in the tile roof(in the early part of video below). I want to keep that and modify the adjacent, but larger glass skylight (~1.5m x 1.8m) you can see later in the video.
A friend of mine did that with an attic. He ended up replacing the Velux tilt window with a Velux window that opened like a door out onto the roof and had a much better clear area. Good for roof access also. He was a physicist and built telescope control systems but his interest was mostly visual.
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Quote:
Originally Posted by JA
Hi Jason,
That's almost exactly what I already have with the smaller skylight an ~0.9m square opening in the tile roof(in the early part of video below). I want to keep that and modify the adjacent, but larger glass skylight (~1.5m x 1.8m) you can see later in the video.
Be interested to see how you counter the natural vibrations and movement in the house.
That's certainly an interesting part of the challenge, but I don't intend, for the moment, to go to longish focal lengths so that may make things more achievable with good old mass, stiffness, damping, vibration isolation of the floor and sitting quietly.
I had a similar, but more difficult challenge professionally, some time ago with vibration isolation of a Metrology Laboratory Co-ordinate measuring machine which in the end worked out well.
The other thing about the job list idea, If you find you keep putting off 1 particular job, try and split it in half, instead of "build frame" break it down, e.g. buy timber, measure and mark, etc, The goal of all projects is to trick yourself into completing it