The Octagonal Observatory

Introduction

These web pages document my design and build of an observatory for my NexStar11 GPS telescope. A commercial observatory costs a fortune and my estimate is that it would cost 10x more than a damage-it-yourself DIY version. There are plenty of options for designing an observatory - my first was a run-off shed - so why an octagon with a rotating roof?

  1. I wanted somewhere secure, waterproof and with a small footprint. Run-off sheds or slide-off roofs require room for opening almost doubling the area of the observatory.
  2. I wanted somewhere slightly more protected while open - I plan to use a computer in conjunction with the telescope plus a CCD (and film) camera.
  3. It had to look ok - a major concern for the wife who has already brought trellis to grow plants up it!

The major design issue is how to get the roof to rotate. Plans for a nice circular observatory were dashed when my material of choice (metal roof) would have created a nice Faraday cage to protect my GPS telescope from ever getting a fix. Surfing I've seen plenty of examples of circular rails being cut from plywood - so that's what I'll attempt to do. No plans at the moment to motorise the roof - the opening is pretty big so that shouldn't be an issue unless I go for massively long photos!

Progress

The build is summer 2003 and progress so far:

  1. A model of the observatory in POV-RAY was created to make sure I had all the dimensions right. And... importantly... the family signed-off on the plan!

    klaatu barada nikto

  2. I created a detailed plan (in PowerPoint) for each of the sections in order to think through the various design issues and to cost it out. Click here to bring up a new window with an html version of these plans.
  3. Days 1 to 2
    All the wood for the base and walls has been cut and the base pretty much constructed.
  4. Days 3 to 5
    Base completed - see detail here.
  5. Day 6
    Walls constructed - I now need to figure out the strongest way to fix them together. I'm using brackets at the bottom of each support and will use the rail to hold the thing together at the top. More details here.
  6. Day 7-9
    Walls attached and levelled. Rail cut and final parts of the roof cut and attached together
    .

  7. Days 10-17
    Messed up on the roof construction. I made version one from 18mm ply which was far too heavy to keep its shape and roll on wheels easily.
    Roof version two made from 4mm ply over a 19mmx38mm wood frame was light and rigid. Covered the roof with felt (nailed and stapled) and finished edging with roofing glue.
  8. Days 18-19
    Roof opening construction. First attempt using corrogated clear sheeting failed due to lack of good seal. Replaced with uPVC twin-walled sheeting instead. Used drawer runners to slide the overhead and sloping roof panels.
  9. Days 20-21
    Finishing touches - painting, lock fitting, running power lines and installing the telescope.
  10. Day 22 - First light!!! More pictures here