Observatory Design Page

A Tale of Two Domes

This webpage briefly describes the two domes I constructed during 2008 and 2015. Additional construction details can be found on the webpages associated with the two domes: Inexpensive Steel Frame Dome and Bent Wood Laminate Dome. An inexpensive steel frame dome (2008) and a bent wood laminate dome (2015) are shown in the below left and right photos, respectively.


Inexpensive Steel Frame Dome

During the winter of 2008, I decided to build an observatory. I considered building both roll off and domed observatories, and finally decided that I required the greater wind protection offered by a dome. Since one of my telescopes is a large Newtonian that I want to mount equatorially, I required a large dome. I settled on a 3.3 meter diameter dome on top of a 1 meter high, round base structure. I began by looking through a large list of links to other home built observatories at the Amateur Astronomical Observatories Website and selected two potential dome designs: foam geodesic and plywood birdcage.  

I really liked the foam geodesic domes and initially decided on this type of design, but the price of the styrofoam, fiberglass, epoxy resin, and marine paints was too high. This clashed with my basic theme of keeping everything simple (KIS) but also more importantly inexpensive. I next considered a birdcage type dome, which is constructed from layered plywood.  This is a very straight forward type design, but I was concerned that it would be very heavy and also very expensive.

My first dome was a modification of a birdcage type dome, using a steel frame covered with a composite exterior roofing material (below photos). This was a very lightweight dome that was very easy to construct at a low cost, so it fit the budget astronomer. I built this dome in 2008 and it survived 7 years of rain, gale and hurricane force winds, snow, and summers.

Completed on October 19, 2008 and "First Light" on Nov. 1, 2008: 


Bent Laminate Arch Dome

My second dome was completed in 2015 and is a birdcage type design that uses bent laminate arches instead of the traditional plywood arch construction (below photos).  I wanted to try a different construction by bending thin wood strips around a frame and laminating them together to arches. The goal was to produce a very strong arch that was thinner and lighter than a traditional birdcage type plywood arch. The laminate arch frame was covered with oriented strand board and exterior roofing materials, so it is a heavier construction. I also replaced the original dome door, that slid up and over the dome, with a double door design.

Completed on Sept. 19, 2015 and "First Light" on Sept. 26, 2015: 

Building Codes

You are responsible for following all local building codes and assuring a safe structure. Be sure to check your local codes before you begin planning the structure; I know of home observatories that were completed, only to be torn down and rebuilt, because the builder didn't follow all local codes. Remember that these codes exist to make sure that structures are safe. Many homeowner associations also have rules regarding what you are allowed to build and you need to check that you will be allowed to build a home observatory. I also recommend that before you start any construction, you take the time to discuss your plans with your neighbors. 

Important: As with anything you build, you are responsible for following all local building codes and assuring a safe structure.
I assume no responsibility or liability for any injury or damages resulting from what you may build. Anything you do is at your own risk, so be sure you know what you are doing and accept all risks prior to beginning. If you have any doubts about what you are doing or lack the necessary construction skills, seek help from licensed construction personnel. 

Materials and Tools

The design theme was to keep it simple (KIS) and inexpensive; this means common materials and tools. The observatory was constructed from the following building materials:
  1. Pine boards
  2. Plywood
  3. Oriented strand boards
  4. Roller wheels
  5. Exterior nails and screws
  6. Misc. fittings (hinges, galvanized right angle supports, hasp and padlock, etc.)
  7. Exterior oil based water sealant
I have a very basic workshop and only used common tools:
  1. Variable Speed Reversable Power Drill
  2. Telescoping Miter Saw
  3. Drill Press
  4. Electric Jigsaw 
  5. Handtools: Hammers, Screwdrivers, Spirit Level, Carpenter's Framing Square, etc.