Star Coin Project
3D printable tactile constellations

About

The Star Coin project started in October 2014 as an astronomy education approach for the visually handicapped. I had recently learned how to design and print two 3D objects over several months using FreeCAD and the MakerBot 3D printers at the Case Western Reserve University think[box]. I was also working as an astronomy department volunteer at the Cleveland Museum of Natural History (CMNH) at the time. The planetarium director, Jason Davis, mentioned their collaboration with the Cleveland Sight Center teaching astronomy. Putting this together with my recent 3D printing interest, it seemed like a great opportunity to print constellations in tactile form. Jason helped set up the first meeting with the Cleveland Sight Center in November 2014. An initial test print of the Big Dipper was shown to them. The response was quite heartfelt as one person said he never really understood what the Big Dipper was until he felt this 3D model. Subsequent changes were made in sizing and layout to arrive at the designs shown on this page. Further development of the designs and methods for use are planned as the education approach is developed. Beyond the coincidence of 3D printing and astronomy there was a third opportunity that provided access to 3D printers. I had been attended a monthly meeting of electronics enthusiasts in a MeetUp group, Charged Conversation. Rick Pollack, president of MakerGear, was at one of these meetings and saw what I was doing. He generously offered to supply sets of the star coins in ABS plastic for CMNH and the Cleveland Sight Center at no cost to get us started. I am currently using SketchUp to develop new constellation designs, and a PowerSpec 3D Pro printer with Simplify3D to make samples.

Design and Use

Image of constellation Orion on 3D disk Each constellation is on a 100 mm diameter disk, although this can be adjusted when printed. The top of the disk has a hole so that it can be put on a beaded chain as a set. In a planetarium, sets of these could be used during the regular planetarium show. At the bottom, the three letter constellation abbreviations were initially used. This was replaced by a reference number that can be used as part of a quiz in a classroom setting.

Black 3D filament material with white painted stars gives the best contrast for those with limited vision. White model airplane enamel paint had worked well to paint the stars and number. PLA filament was used in the constellations shown here. Attaching a thin piece of magnetic sheeting (5x5 cm) to the back of each disk (magnetic vent cover) allows the disks to be stuck to boards with a ferrous metal backing. A lot of white boards have metal backing for attaching magnetic items.

Supplying each student with a small metal board about 60x60 cm (from the office supply section of a discount store) let them easily move the constellations. The relative orientation of the constellations to each other can thus be taught while placing them on the board. Comical stories about the proximity of constellations and stories of the mythical characters can make this fun for the students.

These tactile constellations can also be used to teach constellations to all students. A set of these can be placed on a metal wall board and used for instruction or just fun for kids to learn while playing.

Feel free to use and distribute these. There is no charge to educational organizations under the Creative Commons license. I would appreciate your feedback to help develop the materials and teaching approaches: Bruce Bream, tarrow@roadrunner.com.

Field Experience

An astronomy class was held at the Cleveland Sight Center Highbrook Lodge. Cleveland Museum of Natural History astronomer Jason Davis used the Star Coins to teach astronomy in a different way. Ursa Major, Ursa Minor, and Cassiopeia were introduced and placed on individual magnetic boards. The orientation relative to the north star in Ursa Minor was explained. The boards were held up to help understand the location of the constellations in the sky above.

Someone touching one of the constellation disks Someone helping identify star points on the disks Jason Davis helping someone learn astronomy

Other Ideas

These constellations can be useful in teaching constellations to any school children. Some ideas you might consider:

Presentations

Great Lakes Planetarium Association meeting Star Coin Presentation Charts from 23 April 2016.

Cleveland Regional Astronomy Planetariums, 27 March 2019

SciAccess Logo SciAccess Conference, Star Coin poster session, The Ohio State University, 28-29 June 2019.

Star Coins in the Field

Constellation display The Waukesha Wisconsin Schools Horwitz-DeRemer Planetarium installed a constellation and planet board in the entry room. The planetarium is located in Waukesha County Retzer Nature Center. Planetarium programs are available to the public as well as students in the Waukesha School System.

Sample Lesson Plan

Content Statement
Stars in the sky have grouped into patterns called constellations.
Humans across time have mentally connected stars they perceive to represent objects or people.

Procedure
Introduce what a star is and how it produces a point of light in the sky. Stars are essentially balls of fire. Our sun is the closest example. At great distances stars are faint with some so dim they cannot be seen without a telescope to magnify the light. Magnitude is the term given to the brightness of a star.

Note how people have seen patterns in the random positions of the stars. Astronomers refer to each pattern or group of stars in the sky as a constellation. There are 88 constellations.

Hand out the star coins. Note that each point on the disk is a star. The diameter represents the star's brightness. Lines between the stars make connections that relate to the name given to the constellation.

Explain the story behind each constellation.

Each constellation has been numbered for an identification quiz.

Vocabulary
Star
Constellation
Magnitude

Materials
A set of Star Coins

Evaluation
How many modern constellations are there?
What term is used to describe the brightness of a star?

Discussion Questions
Why did people think they saw patterns among the stars in the sky?
What other patterns do you perceive in the tactile stars?
Do you think different cultures have seen different star patters in the sky?

Science Standard
Use evidence, scientific knowledge to develop explanations.
ESS.35.5c Identify what can eb found in the solar system.


Other sites promoting astronomy for the visually impaired

Current list of Constellation Star Coins

For each constellation in this list there is a sample image and a link to the STL file for 3D printing. Print this Constellation Number List for reference.

Constellation Sample
Image
STL file Ref
Number
Aquarius 3D tactile constellation Aquarius Aquarius.stl 23
Aquila 3D tactile constellation Aquila Aquila.stl 18
Aries 3D tactile constellation Aries Aries.stl 24
Bootes 3D tactile constellation Bootes Bootes.stl 9
Cancer 3D tactile constellation Cancer Cancer.stl 7
Canis Major 3D tactile constellation Canis Major CanisMajor.stl 3
Capricornus 3D tactile constellation Capricornus Capricornus.stl 27
Carina 3D tactile constellation Carina Carina.stl 52
Cassiopeia 3D tactile constellation Cassiopeia Cassiopeia.stl 13
Centaurus 3D tactile constellation Centaurus Centaurus.stl 46
Cepheus 3D tactile constellation Cepheus Cepheus.stl 17
Cetus 3D tactile constellation Cetus Cetus.stl 28
Corona Borealis 3D tactile constellation Corona Borealis CoronaBorealis.stl 31
Crux 3D tactile constellation Crux Crux.stl 33
Cygnus 3D tactile constellation Cygnus Cygnus.stl 16
Dorado 3D tactile constellation Dorado Dorado.stl 50
Draco 3D tactile constellation Draco Draco.stl 20
Gemini 3D tactile constellation Gemini Gemini.stl 4
Grus 3D tactile constellation Grus Grus.stl 47
Hercules 3D tactile constellation Hercules Hercules.stl 12
Leo 3D tactile constellation Leo Leo.stl 5
Lepus 3D tactile constellation Lepus Lepus.stl 6
Libra 3D tactile constellation Libra Libra.stl 25
Monoceros 3D tactile constellation Monoceros Monoceros.stl 21
Orion 3D tactile constellation Orion Orion.stl 1
Pegasus 3D tactile constellation Pegasus Pegasus.stl 11
Pisces 3D tactile constellation Pisces Pisces.stl 26
Sagittarius 3D tactile constellation Sagittarius Sagittarius.stl 15
Scorpius 3D tactile constellation Scorpius Scorpius.stl 22
Taurus 3D tactile constellation Taurus Taurus.stl 2
Triangulum Australae 3D tactile constellation Triangulum Australe TriangulumAustrale.stl 49
Ursa Major 3D tactile constellation Ursa Major UrsaMajor.stl 10
Ursa Minor 3D tactile constellation Ursa Minor UrsaMinor.stl 14
Virgo 3D tactile constellation Virgo Virgo.stl 8

These were the first constellation that I made. These were smaller with the Big Dipper being the first. I added Braille at the bottom to Canis Major. The final size was determined by what was needed to resolve the three belt stars in Orion.
Version 1 of 3D tactile constellation of the Big Dipper BigDipper.stl and Version 1 of 3D tactile constellation Canis Major CanisMajorOrig.stl


This project is developed in conjunction with the Cleveland Natural History Museum through the support of Jason Davis and the Cleveland Sight Center with the support of Lisa Cellura, among others. Initial ABS prints were supplied by Rick Pollack, president of MakerGear.


Creative Commons License
The Star Coin Project by Bruce Bream is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Permissions beyond the scope of this license may be available from tarrow@roadrunner.com.

Last update:16 February 2023