MathMechs extensor User manual

Instructions

A
B
Y Z X
12×A
12×B
4×X
8×Y
4×Z
2×Spring
An extensor is an extending and retracting beam based
on a scissor-like mechanism. Extensors can be connected
together at nodes to build larger expanding structures and
networks. Adding springs to extensors makes self-activated
mechanisms!
Check out MathMechs.com for video instructions.
This set contains:
In this booklet the parts are colored according to their type;
your set comes with a variety of colors for each part.
Welcome to extensors

1
Y-extensor
3×A
3×B
2×Y
Connect parts as shown in steps and to make a length-
two Y-extensor. Repeat step to make longer extensors.
Replace the Y parts with Xparts to make an X-extensor.
2
21
2
3

Extensor Slinger
4×A
4×B
2×X
1×Spring
Warning - do not point
at eyes or face.
Hold the
extensor slinger
closed with
the thumb and
middle finger
of one hand.
Release your grip
to make it jump
out of your palm!
Add a spring to an extensor
where two Aand/or Bparts
connect.

Caltrop
12×A
12×B
8×Y
4×Z
Move all of the
Aparts to one
extensor to make the Wand. Add a
spring to make it magically expand!
Connect four length-two
Y-extensors together
with four Zparts.
2
1

Elbow
8×A
8×B
4×X
2×Z
Connect two length-two X-extensors
together with two Zparts.
2
1

Square
16×A
16×B
8×X
8×Z
Axes
24×A
24×B
12×X
8×Z
With more parts you can build bigger structures.
Further examples are shown on the following pages.

Cube
48×A
48×B
24×X
32×Z
Use longer extensors
to make a cube with a larger
expansion factor.

Dodecahedron
90×A
90×B
60×Y
80×Z
Note that the internal
angle of the pentagons in
Dodecahedron is 108º, which is
close enough to the angle we designed
Extensors to work at, ArcSec(-3) ≈ 109.5º.

Formed from ten Caltrop nodes, this is a
chunk of the crystal structure of diamond.
Diamond
120×A
84×B
68×Y
40×Z

Tetromino
144×A
144×B
72×X
104×Z
Using similar designs you can
build the other tetrominoes,
and other structures based on
the cubic lattice.

Patent pending
© 2018 Henry Segerman