3d Nocturnal Celestial Stardial TJT5/6




Introduction: 3d Nocturnal Celestial Stardial TJT5/6

A Nocturnal Celestial Stardial is best when it's a solid archival material. As such it makes a fine heirloom or engagement present. Time-Journey Tool 5 of 6 is an accurately functioning instrument.

Nocturnal Celestial Stardials were originally called "horologium nocturnum" (time instrument for night), or nocturlabes. Sundials work great, but only during the day. Nocturnal Stardials tell time at night by measuring the stars. The dials move. It works like a charm. It needn't even be configured to longitude and latitude like a sundial.

This long-forgotten instrument aided a few lucky navigators and charmed romantics of the Renaissance. Earliest references include Cosmographicus Liber in 1530, Arte de Navegar, in 1551, and Horologiographia, The Art Of Dialling in 1626. 'Twas rare then as now. 

The outer disc is marked with the months as well as an indicator for each of the 365 days of the year. The inner disc is marked with hours and 5-minute increments. The pointer rotates on the same center axis as the discs. The center axis has a sight hole through which the North Star Polaris can be aligned.

In the northern hemisphere, all stars will appear to rotate about the North Star, aka Polaris. The North Star is very close to the north celestial pole, but about 434 light years away.

The time can be read on my Nocturnal Stardial from any of three reference constellations: Big Dipper (Ursa Major), the Little Dipper (Ursa Minor), or Cassiopeia.

Recommended Materials and Processes:

 Computer with internet access
 3d modeling software (or download my 3d model for free)
 access to 3d printer (I use Shapeways.com)

Step 1: 3d Modeling(?)

I built this Stardial in Rhinoceros 4.0 software. Then I had it 3d-printed. You have a few options on how to make one for yourself:

1.) model your own in 3d design software. Rhino costs $995. or $195. for students and teachers (2012 numbers).

2.) Why pay a thousand bucks for modeling software? Several excellent FREE 3d-modeling software can be found at:

3.) Download my model for free. I believe it is the only downloadable 3d Nocturnal Stardial model anywhere in the world. It's available here:


Step 2: Building in Rhino

A recent instructable I created provides engineered PDF blueprints for modeling a functioning Nocturnal Stardial of your own aesthetic design.

This downloadable PDF below can be cut apart with scissors and assembled with a rivet or eyelet into a functioning paper Nocturnal Sundial. Instructions for that are to be found in my instructable "2d Nocturnal Celestial Stardial TJT1/6" found at: 


However, if you are prepared for some 3d modeling, then this PDF will give you the engineered, basic architecture from which you can create a unique, and functioning 3d model.

Step 3: 3d Modeling Overview

The 2d PDF of the Nocturnal Stardial has 3 separate components.
In Rhino, I colored the 3 components differently to visually distinguish them:

Dial A is blue
Dial B is red
the main piece is green

These 3d objects are built of many pieces. For example, the green component has 365 geometric shapes arranged symmetrically around its circumference, just for the days. The overall number of components to the stardial 3d model is about 1,000. It is not as hard to model as one might think. For example, the 365 units around the perimeter are actually just 73 identical sets of 5 units.

Illustrating each step in modeling this object may be too lengthy for an instructable. However, one could model an equally-well-functioning stardial much more quickly. For example, each of the three components could be essentially planar. Printing out and assembling the paper PDF Nocturnal Stardial would help one to see the essential simplicity of design and function. That's a great place to start. My design is a whole lot more sculpturally intricate than necessary, but that's how I roll.

My 2 previous instructables walk through the actual modeling steps of building two different 3d models form beginning to end. Here they are:

Step 4: Print It UP!

Order or make a 3d print of the model.

Step 5: How to Operate the Nocturnal Celestial Stardial

How to use the Nocturnal Celestial Stardial:

1.) Find one of the 3 reference constellations, the larger reference star of it in particular.
2.) Align the appropriate constellation dial (Dial B) to the day's date.
3.) Hold instrument in a vertical position whilst facing north.
4.) Sight Polaris, the North Star, through the hole in the center of the instrument.
5.) Rotate the long arm (Dial A) to point to the reference constellation.
6.) The time units on Dial B are in 5-minute increments. The flat edge of Dial B will show the time increment to the nearest 5 minutes.

Note: for greater accuracy one could point directly to specific stars within the chosen constellation:

  Schedar within Cassiopeia
  Kochab within Ursa Minor (the Little Dipper)
  The Pointers within Ursa Major (the Big Dipper)

Step 6: Seize the Moment

Few people on the history of the planet have had a fine Nocturnal Celestial Stardial. Here's yours.

Lose not yourself in a far off time, seize the moment that is thine.
Friedrich Schiller

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    Mark Baker
    Mark Baker

    Question 3 years ago on Step 6

    Have NOCTURNALS been constructed that correctly tell time for the SOUTHERN HEMISPHERE?


    9 years ago on Introduction

    As I said in your last 'able I had never heard of such a thing. I've been wanting a 3D printer so bad I could taste it, and this looks so so so cool!! Great 'able and again thanks for sharing this amazing tool!


    Reply 9 years ago on Introduction

    I like your paper art. I wonder if you're a teacher and/or artist.

    Yup once one of us get a 3d printer we need to share and/or collaborate!


    Reply 9 years ago on Introduction

    I like this plan! :) I am an artist who became an art teacher. :) I have a BFA and an education degree. I really dig working with kids, and when I was younger and going to school I never would have dreamed this is the role I would find myself in. However, it allows me to create my own work (someday perhaps I will post that stuff) and kick back and get to stay a kid at heart and instill the passion and love for art in all fields of study to young minds. I'd do it for free, but I am happy they pay me, art supplies are expensive! LOL


    Reply 9 years ago on Introduction

    I teach art to kids at my mom's Montessori school one day a week. I'd be into brainstorming on lessons/projects someday.

    One idea I had regarding this stardial was to make a whiter/more basic design so kids could assemble & color/design their own.


    Reply 9 years ago on Introduction

    That sounds like a fantastic plan! What age of kids are you working with? Could it be made using balsa wood? It's light weight, and cuts very easily with an exact-o knife. Of course that would have to be much older children, or precut wood forms they could sand. Humm, with clay it would shrink 20%, so that might not work. A thin plastic might work out. Where I live we have a factory that makes plastic parts for medical equipment, and they are very generous and will give us scraps. We have made plastic bats for wheel throwing and many other things for the classroom, you could always check out things like that. Something solid however, using a basic design would be so cool because it could be something they would keep. My wheels are spinning. :)


    Reply 9 years ago on Introduction

    it's a shame there's not a really cheap metals clay, like (Precious Metals Clay). I'm working with 5-8 year olds. Today we made the paper versions. I printed them, they colored them in. I made a version with all the color and shadows pretty much stripped out. They cut them out and we assembled them with eyelets. The tool and 100 eyelets only cost about $7. bucks at Hancock Fabrics, formerly Joann Fabrics.