Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

Search the Community

Showing results for tags 'dome'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • Welcome
    • Welcome
  • Beginners
    • Getting Started General Help and Advice
    • Getting Started Equipment Help and Advice
    • Getting Started With Observing
    • Getting Started With Imaging
  • Community
    • Official SGL Announcements and Events
    • StarGaZine
    • SGL Challenges and Competitions
    • SGL Star Parties
    • Star Parties & Astro Events
    • Celestial Events Heads Up
    • The Astro Lounge
  • Retailers
    • Sponsor Announcements and Offers
    • FLO Clearance Offers
    • IKI Observatory
    • Supplier Reviews
  • Astro Classifieds
    • For Sale / Swap
    • Wanted
  • Equipment
  • Observing
  • EEVA (Electronically Enhanced Visual Astronomy)
  • Imaging
  • Science
  • WADAS's WADAS Discussion Forum
  • Beaufort Club's Topics
  • Swindon Stargazers Club's Topics
  • East Midlands Stargazers''s Topics
  • Central Scotland Astro's Topics
  • SGL Cumbrian Skies's Topics
  • Herts, Beds and Bucks Group's Topics
  • SGL East Anglian Group's Topics
  • South Leicester Observers's Topics
  • South Wales Group's Topics
  • SGL Surrey Observers's Topics
  • South Yorkshire Stargazers's Topics
  • Yorkshire Astronomers's Topics
  • Devon and Cornwall's Topics
  • West Midlands's Topics
  • Essex Cloud Dodgers's Topics
  • Essex Cloud Dodgers's New equipment
  • NLO and Planetarium's Topics
  • Astronomical Society of Edinburgh's Discussion
  • Dorset Stargazers's Topics
  • Hairy Stars Club (Comets)'s Tutorials and Guides
  • Hairy Stars Club (Comets)'s General Discussion
  • Hairy Stars Club (Comets)'s Observing Campaigns
  • Hairy Stars Club (Comets)'s Analysis results
  • Hairy Stars Club (Comets)'s Useful Links
  • Pixinsight Users Club's Pixinsight Discussion Forum


  • Astro TV
  • Celestial Events
  • SGL Calendar
  • Astro Society Events
  • Star Parties
  • WADAS's Events
  • Beaufort Club's Events
  • Astronomical Society of Edinburgh's Events
  • Dorset Stargazers's Events


There are no results to display.

There are no results to display.

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start





Website URL







Found 16 results

  1. After automating the dome on my Pulsar Obsy which has been a revelation, I have spent a considerable time researching how I could automate on what is a very basic manual shutter. The existing shutter slides on the aperture side of the dome and supported by two curved aluminium rods at the rear. What I will require is to create a runner system to allow the shutter to open & close smoothly, be aligned & contained to enable attaching a motor and drive system, thus allowing software automation. The rollers are 30 mm dia nylon roller bearings, four per side of the shutter opening. This will allow the shutter to slide smoothly over the open aperture. The rear side of the dome needed to be built up so I could affix tracks to enable the shutter to slide smoothly to the rear of the dome. This was relatively tricky as I had to build rear track support blocks to line up with the existing shutter. I plumped for wooden supports as I had to mount the on a sloping curved dome and as they had to be mounted vertically, creating some rather complex compound angles and curves. These were bonded in place and further secured with stainless screws from within the dome. Then having formed the arc in which the shutter will run I attached UPVC strips to complete the assembly. The sides will be cladded with UPVC. The calculations had to be quite precise as I didn't have much breathing space To be continued........... Steve
  2. Hi all I am finally getting to the point of having a working dome and shutter driver from an electronics point of view: I have alpaca controllers and drivers for both, sensor switches in place for the shutter travel, encoder for the dome rotation, relay latch for unlocking the shutter, motor drivers for the opening motor. I've also put in place a bicycle-wire based winch system to raise and lower the lower shutter on an endless rope system. What's missing is this: When winching, the lower shutter rises on the rails up the slot and under the lower shutter to a certain point and then brings the upper shutter with it by virtue of pressing under the bottom edge. When the lower shutter raises to a certain point on the cycle, gravity takes over, the top part of the shutter unhooks from the lower part and slides down the back of the dome with a a crash into the buffers. I'd really rather that didn't happen, since the buffers and the dome they are attached to wont last long doing that regularly. I tried putting shock cord elastic between the two so the larger upper part couldnt run away but the lengths are wrong and wouldnt allow the shutters to close properly with the right length to prevent or at least dampen runaway. What I am looking for is ideas to prevent this happening in a reliable way so the dome automation can do its job, night after night. What I find is writing about the problem also helps me think about it, so hope this is useful. The winch system: The bicycle wire system has rollers on the inside of the shutter rail that guide the wire that is pulling the shutter up , which is fastened to the lower edge of the lower shutter. The wire goes up to the top of the dome, round a pulley and then back again, this time inside bicycle wire guide tube which mean I can more or less run it where I like with a small amount of give. In this case it runs back along the rail down to the winch. The wire wraps around the winch about 3 or 4 times and then fastens on the shutter again. Ideas: Something to make the upper shutter stick to the driven lower shutter on the way up and come apart on the way down ... Something to dampen the crashing of the shutter into the buffer... hope this stirs your creative engineering juices. Mike
  3. Following on from my other mini-observatory threads, I'm now thinking of a small dome observatory for my widefield imaging rig. Several previous ideas for a mini observatory have bitten the dust! I have a number of thin aluminium sheets the I bought for my earlier cylindrical roof mini obsy that can be bent into the sections of a multi-sided dome. Why a dome? Well, it is more compact, requires less power to drive - this observatory and contents will be fully automated - and a dome provides more protection from wind etc. No space is required inside for a person in this case - just a Raspberry Pi 3 for controlling everything with INDI drivers. Not even a laptop.
  4. I'm in the planning stage for my own observatory and have been looking at Roll-off designs, but am now having a think about a possible DIY dome. My design would be based on a geodesic. At present I am thinking about how the dome rotation would operate. Having looked at several online dome builds, most people seem to sit the dome on a circular base, which either rolls on casters mounted on the walls somehow, or the base actually has the casters which roll on the top of the wall in some way. For the sake of discussion, let's imagine that there are two circular rings, one on which the dome rests and which has 6-8 casters on the underside that roll on an identical circular ring attached to the building walls. When I exert a tangential force on the dome in an attempt to rotate it, it seems to me that the dome will actually want to move sideways (not rotate), which several online sources seem to confirm. People seem to solve this issue by making the castors roll on some kind of track, or they fit guide casters to keep everything in the right place, essentially forcing rotation. So, because rotating is not the natural tendancy of the dome, it seems to me that the caster wheels are continually being forced to steer round a curve when actually they just want to go in a straight line tangential to the circular rings. Thus, I would expect them to kind of skid a bit as they operate, a bit like a bicycle might do if it had to follow a circular path but I wasn't allowed to turn the handle bars at all. (Actually, the bicycle probably wouldn't be able to follow the path in that case as there would be no guide force to make it skid). This leads me to believe that flat bottom wheels would be a bad choice because they'd create too much friction and make it hard to turn the dome. Much better wheels would be rounded ones (donut-shaped) that have minimal surface area in contact with the rolling surface so that skidding friction is kept as low as possible. Is my thinking logical here, or am I just not on the right track at all? Assuming I'm understanding what is going on well, it seems to me that the best thing I could use would actually be spherical ball bearing castors (think like mouse ball) that could rotate however they needed to help the dome rotate with minimal friction. I'd be looking to automate the dome rotation later, so having something that moves easily would be fairly important given that I'd probably go for a friction drive wheel. Does anyone have any experience here or a good understanding of the mechanics involved to give some good advice on how to make the dome easy to rotate? David
  5. Hi, I need to lift off the dome of my 2.2 metre Pulsar observatory so I can smooth out the joints between the 4 sections. They are causing problems when the dome is rotated. When I bought the dome it was installed by Pulsar so I have no experience of lifting the dome on or off the walls. My plan is to use 4 Acrow props to do the lifting so I can do it as a one man operation. I assume that it is best to place the props outside the dome and lift using the edge of the dome. Can I ask anyone with experience of these Pulsar domes if this is the right way and are there any snags? Thanks, Hugh
  6. I've survived with a little table and a beauticians make-up chair in my 2.1m (7ft) dome for many years now, but i think i could do with some more storage now given the upcoming changes to my setup - moving from a Milburn wedge mounted Nexstar C11 to an EQ8 mounted C11+Opticstar 127mm Apo dual mount - so I might just need somewhere close by to keep ancillary stuff such as bahtinov masks, solar filters,dew heaters, cables, tools and other non-electronic stuff (electronics come back inside the house at the end of every session). so - suggestions welcome - commercially available stuff or home built. thanks in advance Neil
  7. I have a large (maybe 4 metres, 12 feet in diameter) metal dome which is in need of some refurbishment. Does anyone have any particular advice about what to cover the interior with? Previously there was some polystyrene panels fixed up with wallpaper glue which over time have broken off and land on my optics and equipment, something I'm not very happy about. Take a look a the video or pictures in the instagram for what has happened over time (https://www.instagram.com/rhulobservatory) Is there any particular need to cover the interior at all? Thanks, Stewart
  8. Hi Guys New member, ancient ATMer. I have joined to directly access Pulsar dome owners' fund of information. I am building a raised platform 8' off the ground to provide a much bigger sky. Trees and hedges surround and interrupt our dark rural property. Our modest 1.5 story home is on the southern border of our large garden. Fortunately neighbours with security lights at a hundred yards south and SW are safely hidden by the house. Increasing age demands shelter from the almost constant wind. My two main OTAs are now much too heavy for easy lifting: I am using a chain hoist and nested stepladders! I have a 10" f/8 reflector with premium optics and a 7" f/12 R35 iStar refractor. [Presently folded.] Both ATM builds. My almost completed, massive DIY GEM has 2" shafts and lots of heavy aluminium. ie. Immovable! It is running AWR IH2/ASCOM drives to 11" and 8" Beacon hill wormwheels. The images show my mounting on a temporary test stand. Now the real reason for my unscheduled interruption: [Much as I like talking about myself.] I am torn between a DIY all aluminium, rotating "dome" of the cylindrical roof variety or buying a Pulsar 2.7m. dome only kit. Making a hemispherical dome is a long term exercise in geometrical and sealing frustration IMHO. The off-the-shelf Pulsar 2.7 is rather cramped for my 2 meter long Newtonian even when the dome is mounted on a much larger "box". Does any recent Pulsar 2.7m dome purchaser have the minimum internal dimensions between opposing quadrant ribs? I understand the 2.7m is actually 2.6 from Pulsar's own drawings but that may be external. With so little clearance available I really need an accurate figure. Thank you for your patience if you have reached this far. Regards, Rusted
  9. I and my girlfriend has come home from a one week travel at Malta, a small island in the Medeterranien Sea. About a mount before we go I came in contact with an amateur astronomer down there, Maurice. He invited me and my girfriend to visit him and his DIY built observatory. The observatory is built on top of his house and it has a real dome. If you find it interesting to read about it I have done a small report from our visit at the Malta observatory with photos: http://www.astrofriend.eu/astronomy/observatory-sites/malta-maurice-observatory/malta-maurice-observatory.html The Raven and the Owl observatory, Malta. After this visit it's hard to understand why we stay in Sweden where we live, when it's dark it's also very cold. We often have from -20 degrees to 0 degrees Celcius temperatures. Now adays we don't have many clear nights either. /Lars
  10. Like many of us, I was a little bit peeved at the time it takes to move about 50-100Kg of kit, set it up, make all the electrical connections, polar align, calibrate the GOTO system and fix anything that has gone wrong (it always does) prior to starting out a session - and that's if it's still clear. And then there's the packing it away again at the end of the night. It was such a chore that unless the forecast was clear all night long I tended not to bother. To make my hobby enjoyable again, I needed an observatory. There are a number of options: 1) Roll-off roof 2) Roll-off shed 3) Clamshell 4) Dome These all have their pros and cons. 1 & 2 are cheap, but need additional garden space to roll them off. The way my garden was set up, and the location I wanted the observatory, meant that I discounted them. The only clamshell easily available in the UK is the SkyPod, and whilst I considered it for some time, I finally got put off by the trouble imaging straight up and the reports of leaks. So that left a dome. The problem with a dome is that they are expensive - and for imaging they need automating (even more expensive). Still, that seemed like the best solution for me. In The UK, the dome that is most easily available is the one from Pulsar observatories. It is available in 2.2 and 2.7m sizes and can be made in white or green (possibly other colours too, white and green are the only ones I have seen). I had seen a dome at a fellow astronomers house - and he had successfully motorized it which meant that I could follow his plans. I'm, OK at tinkering with things, and can actually even be good at it, but for expediencies sake I'd rather get something off the shelf and I'd be rather upset if I found that I couldn't motorize it as I wouldn't be able to image which is my only interest in the hobby. So when Pulsar adjusted their design (see later) and made a fully motorised observatory "off the shelf" an option I decided to go for it. I bought a dome, dome controller, shutter controller and a Shelyak Dome Tracker. Pulsar 2.2m Dome Oberservatory Shelyak Dome Tracker I took a while building the base in my garden - there's a separate thread for that. It needs at least a 2.4m circular or square concrete slab. I went the circular route as it's much harder to build. They suggest a 1m square base for the pier, but I decided 75cm would be more than enough. I made a £500 deposit by credit card (for the protection it offers) and then the rest was paid by bank transfer 3 months later when the dome was ready to deliver. Unfortunately they are built in Norwich and I live in Somerset, so there was a hefty delivery charge. They also offer to assemble everything for a small fee and given that I was into this for quite a sum already, I thought I may as well ensure it got set up properly. I bought an Astro Engineering pier from them too. On the appointed day the guys from Pulsar arrived and set about work, fortunately in good weather. They were finished by mid-afternoon and showed me how the observatory worked - as well as installing up the basic Shelyak Dome Tracker software on my PC. Unfortunately we hit a bit of a snag here, as it wouldn't work! I got a second laptop out, and fortunately it did work on that - but when I checked it again a few hours later after they had gone, it didn't work anymore. Time to pull my hair out! To cut a long story short, I had email communication with the guys from Shelyak and Pulsar over the next 24 hours - they identified a problem with a component not working properly at low temperatures (a December install) and they sent me a new unit. They also wrote a new driver, which meant that the faulty component wouldn't cause trouble anymore anyway. Good service. When I finally got permanent electricity installed to my observatory, I set up my kit properly. The dome moves by two motorised wheels (blue) pressing on the side of the dome. These are powered by a 12v 10a transformer. There is another wheel (the grey one) which is attached to a rotary encoder so the dome knows how far it has travelled. The "home" position is set by a metallic sensor - mine is at 290 degrees. You can see it in between the IR sensors below - it's just a bit of tin foil. When the dome is told to home itself, it rotates until it finds the home sensor and then sets its internal position to 290. From there on, it counts clockwise and anticlockwise motion via the rotary encoder. In addition to the computer control, the dome can be set to track at sidereal rate (or various fractions/multiples thereof - remember, the dome isn't equatorially mounted) if you didn't want to use a computer. The Shelyak unit is nicely hidden away behind the dome controller metalwork too. It connects to the computer via RS232, but they throw in a USB-RS232 cable in case you need one. The shutter mechanism is attached to the dome part which makes getting power to it more difficult. The solution that Pulsar have come up with is a 12V battery and a solar panel. To send signals from the Shelyak Dome Tracker, they have utilised an IR connection. The open/close shutter will thus only work when the dome is at the home position, as this is when the IR sensors are aligned. It closes the shutter by means of a chain and sprocket. There is a manual open/close button in addition to the computer control. To get the dome automated you need to enter a few details, such as the size of the observatory, the number of steps for a full revolution, the position of the pier how high the centre of the scope is above the rotation axis of the mount. After that, it's plain sailing - rather than use the normal ASCOM driver for the mount, you use the ASCOM Dome Control driver instead (comes with ASCOM) - which itself connects to the dome and to the mount. You slave the dome to the mount and then when you issue slew commands, it moves both the dome and the mount to the right position and keeps them there throughout the night. And this is it in action:
  11. Hi all My dome is beginning to look a bit ratty after 20 years or so, so I want to replace it with a new one. I've had a close look at Pulsar and ExploraDome and the others, but I don't want to spend the wonga for a large dome and then build lots of bits to make it interface to the building. Also with the dome sizes at 8ft, 10ft, etc I'd want something like the 10ft at least which is expensive even in kit form. So I got to thinking about GRP again - I built the shutter on the dome from a mould I made and a bunch of other pieces to go with it so I feel competent about how to do this - but if I was to get the investment in, it might as well be for a mould rather than a one-off build. Which begs the question - who else would be interested in investing in a SGL mould for a 10foot dome ? The last time I worked out the costs of producing the mould it came out at about £800 in materials - I'll do my sums again to validate this and post it up here. This of course was without labour - that's essentially free. I am thinking of a dome design with two identical hemispherical sides with raised facing lip two base annulus segment rings which form teh lower edge of the dome hemisphere two central section annulus short segments which form the lower edge of the central segments one central arc for the back of the dome joininbg the hemispheres One main shutter which rolls back along the roof line One smaller shutter which may get lost in the design stage so 5 or 6 main moulds for design and build. The moulds will be built from OSB and ply cladding before glafssfibre cladding. The anticipated cost per dome as a kit would then be of the order of 600 ea. based on materials only. Admittedly this is based on my requirements and glosses a lot of the details - what dooes it run on - who provides the wheels/ring/shutter hinges/motorisation etc ? Anyone interested ? I'd post a link to my current obsy but I need to work on the webserver. Try http://www.skybadger.net/skybadger for a pic... Cheers Mike
  12. Hi, I'm after some advice on dome slaving. I have a Pulsar 2.2 metre with the dome rotation kit (and two equipment bays) arriving at the end of November and I'd like to slave it to the hand controller rather than buy Maxim DL, SGP etc. Is this possible? My mount is a CGX-L with the standard handset. I use SharpCap Pro to capture images and I am not looking to change my setup drastically nor spend anymore money at this point given what the observatory has cost me. Thanks in advance! Adam
  13. Last October I started a topic (here) seeking help for a "challenge" I had with pointing side-by-side telescopes through the narrow opening in my motorised dome. After a lot of research, going back to first principles on spherical geometry and teaching myself how to do Visual Basic programming - I've come up with a software solution I've called DPoint. It's running on my Windows 10 Observatory PC and acts as a "pointing controller" for the dome. I set up the dome and telescope geometry measurements in DPoint and tell DPoint how to connect to the dome and telescope. The software then gets the Alt-Az data from the scope, performs some maths using my scope configuration and hey presto, DPoint works out where the dome needs to point and tells the dome to go there. DPoint polls the scope every few seconds and tells the dome where to go - this lets the dome follow the scope when the scope is slewing. I've been really pleased with how well this has worked - I can select the scope I want to use and DPoint positions the dome opening so the scope is right in the middle of the opening. Here's some screen shots of what DPoint looks like. First is the configuration tab where you set up the dome and scope geometry, for some reason I built it to support five scopes (I only have two but clearly had aspirations for more?): Next is what I called the Setup tab. This is where you connect to the scope and dome and select which scope you want DPoint to slave the dome to. DPoint remembers everything you configure but I also added some Import/Export buttons to make it easy to backup or moving the configuration data around: DPoint is the "operational" tab. In the top half I show where the scope is pointing, where DPoint thinks the dome should be pointing (Target) and where the dome is actually pointing (Current). To slave the dome to the scope you just tick the "Slave Dome to Scope" checkbox. I added the bottom half of this tab to give me full manual control of the dome - I can nudge it left or right, slew the dome to a specific azimuth, Park the dome, Sync the dome to the Target azimuth, and as always, have a big Stop button: The two controls on this tab I haven't mentioned ("Use DPoints" and "Add") are for another pointing mechanism I built into DPoint but haven't fully tested - because I found I didn't need it. If you find that DPoint has quite centred the scope in the middle of the dome opening you can manually move the dome and when it's in the right position press the "Add" button. This adds a "DPoint" coordinate to a database DPoint builds up. If you have enough DPoints in the database, you can tick the "Use DPoints" checkbox and DPoint calculates the Dome Target as normal but then looks at the nearest DPoints in the database and works out a new Dome Target by blending the DPoints data with the original calculation. This seemed like a neat idea at the time to compensate for any non-linearity in the dome geometry or dome pointing (e.g. my dome is not actually level !). However, the maths works fine without having to get the DPoints stuff working. So I can now happily leave the observatory to run my photographic command scripts overnight with the dome following the scope around - I even (eventually) got the setup to handle meridian flips in the middle of the night. All I need is a dark sky and no clouds ....
  14. Hi guys! I thought I'd pass on this link to a blog I am constructing. I intend to detail and illustrate all the steps involved in the construction of a 2.2m square dome observatory from its conception to it's complete outfitting. I am an amateur astronomer and most of the stuff I used in the making of the dome, apart from the actual construction materials was from recycled stuff and bits and pieces I managed to scrounge. A lot of the outfitting electronics and gadgetry came from cheap Asian sources and the circuitry and software was again partly home grown or borrowed from other sources. Time, patience and a generous helping of youtube videos and forums like this one are a must if one gets stuck but thankfully one will always find the answers if one digs deep enough. Anyways ..here it is for any of you who want to browse..The blog should grow steadily as I add more and more information and pics and of course anyone interested is welcome to drop me a line on this forum or by email. There is a lot of ground to cover and so it might take me a while to finish uploading it all ..but after all...hey ...it took me a year and a half to finish! Welcome to The Raven and the Owl Observatory ... a home-made little portal to the stars... https://ravenandowl7....wordpress.com/ Dark skies Maurice
  15. I have a steel pier for sale. This was purchased along with a pulsar dome and believe it is an older Pulsar model. The pier sat in a yard, exposed to the elements for a few years before I purchased it so there is some surface rust and flaking paint but will clean up nicely. £250 and buyer will need to collect from Suffolk.
  16. Hi Everyone. I'm almost finished building a new dome and I have installed 12 volt motors / gear boxes to drive the dome. Now I am wanting to control the dome from my computer, so that the opening on the dome is always in line with the telescope. At this stage, thats all I want - I don't need the computer to open / close the shutter or to install a weather station or anything like that. My question is, what would be the simplest / cheapest option to achieve syncronisation between the pointing of the dome and telescope? I was wondering about using a raspberry pi or something like that? I've never done anything like this before, so if anyone has an idea, I'd be really keen to hear it. Thanks very much! Ross
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.