Skip to content

Make Sense of the Hoberman Sphere / Circle, Linkage

Creation's quality: 5.0/5 (1 vote)
Evaluation of members on the printability, utility, level of detail, etc.

3D model description

####Make Sense of the Hoberman Sphere/Circle

The Hoberman sphere is a beautiful structure (Hoberman, 1990, 1991), appealing to children and grownups alike. Mathematically, it is an extension of the traditional linkages. Taking two bars of the same length and connecting them in the middle, we get a pair of scissors, the four vertexes of which form a rectangle. Adding more and more, we get a retractable handle (or lift), a long line that never becomes a circle.

However, if we bend the bar a little, say 30 degrees, the math magic happens—a retractable circle. A short analysis shows that one need 360/30 scissors pairs to make a circle. Of course, if you bend it 20 degrees, you would need 360/20=18 pairs.

3D design allows us to build Hoberman circle to help students understand and appreciate the power of mathematics and design. The straight bar is 80mm; the bent one has two 40mm sections.


Step One: Make a Line of Scissor Pairs Using the straight bars. It is still fun to play with it.
Step Two: Make a Hoberman circle using 12 pairs of scissors (24 bars) and 36 pins.
Step Three: Play around and ask questions.


  • 3D file format: STL
  • Publication date: 2019/01/18 at 18:23



Designs 217
Downloads 9.6k
Followers 82

STEAM educator, learning from and working with K-12 STEAM teachers to explore new ideas of teaching and engagement. I firmly believe ART is at the core of STEM learning or all human learning! I owe my ideas and designs to the hundreds of K-12 children and teachers and university professors I have had the pleasure of working with, in multiple disciplines-- math, science,engineering language arts, social studies, early childhood education and more! All mistakes, of course, are mine! There is no warranty or liability whatsoever implied or explicit behind the designs or ideas. They are all posted for their potential educational values.

When working with children, please strictly observe all safety and health procedures! Please refer to the NSTA safety guides:




Best sellers of the category Art

Add a comment

Would you like to support Cults?

You like Cults and you want to help us continue the adventure independently? Please note that we are a small team of 3 people, therefore it is very simple to support us to maintain the activity and create future developments. Here are 4 solutions accessible to all:

  • ADVERTISING: Disable your AdBlock banner blocker and click on our banner ads.

  • AFFILIATION: Make your purchases online by clicking on our affiliate links here Amazon, Gearbest or Aliexpress.

  • DONATE: If you want, you can make a donation via PayPal here.

  • WORD OF MOUTH: Invite your friends to come, discover the platform and the magnificent 3D files shared by the community!