1st October 2023 Disposal of my 4.3m dome project:


You may wish to reload the page to ensure you see the latest update.


 Sunday 1st October.

 I have decided to dispose of my 4.3m dome project. 

 Following the death of my wife in early 2022 my interest in astronomy and my build projects has not returned. 

 So now I am spreading the word that the dome project may be taken away free of charge. It has cost me around 40,000 Danish Kroner so far. Over £4000 equivalent but I no longer care.

 The dome is large and heavy but breaks down into three, large segments plus the shutters. Being simply unbolted. Provided there is enough manpower available! I worked entirely alone and it required ingenuity to manage the weight safely. 

 As I live on SW Fyn, in Denmark, those likely to be interested in this project will need to consider transport. They will have to muster at least three strong men to handle the heavy and awkward segments.

 The dome segments were delivered to me on a car transport trailer. Typically available for local hire from garages, petrol stations, etc.. The pickup which brought the segments was fitted with a small crane. There was only the driver to unload it. Two, or preferably three strong men could manage the loading without a crane.  This would have been preferable to avoid scratching the fibreglass.

 The ladder leaning against the dome, in this image, is 3.3m long. It was really too short and required I climb onto the top of the dome to work on my hands and knees!

 My 3m/10' plywood dome, on its two storey building, is in the background. I had already enlarged the observatory building for the bigger dome's footprint. Though sadly it was never lifted into place. That is a full sized 3.3m builders ladder in the image on the left above. My rural garden is surrounded by ever taller trees. Making the expense of hiring a crane increasingly pointless.

 Warning; Do not be driven by greed or over-ambition! This dome is 4.3m in diameter. Over 14'. It weighs around 500kg in total at a guess. Each long and curved segment weighs around 150kg. The very awkward balance of the various parts is very difficult to manage without very serious muscle!

 The spherical shutters run on sixteen, large, inline, roller skate wheels. The dome rotates on fourteen, high quality, 180mm, industrial rollers with needle roller bearings. Laminated plywood rings are provided. Bolted and bracketed to the skirt of the dome. To allow the whole arrangement to be easily taken apart. Yet provide a smooth and stiff surface for the rotation rollers.

 This was my plan from the very beginning. To make a large, observatory dome build as practical as possible. For anyone wishing to copy the same project. The sheer size of the dome would otherwise make it difficult to manage for many amateurs.

 It would almost certainly require crane hire. Rather than a bunch of willing or voluntary enthusiasts. Getting together, to rapidly complete a working, observatory dome of over 14' or 4.3m diameter. With a completed price tag of under £5k. Instead of £50k for a commercial dome of this size.  

BTW: The fibreglass segments are readily available in white. I chose green for my rather conspicuous, two story, raised, rural observatory. Which can be seen from the road. The basic [donor] dome is a calf rearing shelter for farmers. I saw its potential the moment I saw one in a local field!

The manufacturer of this particular dome is Agritech.SRL. An Italian company with local dealers in many countries. They call it their Spheribox. I ordered their normal dome [in green] plus one extra roof [top] segment. To give me enough material to make the shutters. They were kind enough to comply with my request. 

 The basic dome was supplied by a Danish, agricultural equipment dealer as the local agent for Agritech. Before you rush off to order a donor dome for yourself remember that the build requires considerable inventiveness [and considerable expense] to modify into a true observatory. 

 It took me months to progress to the point which I finally reached. Though working alone slowed my progress. Due to the weight of the various components.  

 Just reaching the top of the dome from the outside required ladders at low angles. Needing extra security to stop them sliding away! I used a compost sack or large paving slabs at the base. With foam pipe insulation to prevent the ladder from scratching of the dome's surface. Wrapping the ladder with foam would have been better. Either option provides increased safety due to friction. Access to the top of the dome from the open slit is rather limited due to the sheer scale of the thing.