MathMechs makes mathematically meaningful mechanisms. We prototype in 3D printed materials then mass-produce in injection molded plastic.


An extensor is an extending beam based on a patent pending scissor-like mechanism. The extensor construction kit lets you build expanding structures from Y-extensors (extensors with three arms) and X-extensors (extensors with four arms).

Extensors can be connected together at nodes to build larger expanding structures. You can add springs to make mechanisms jump open!

We currently offer a starter set with 40 injection molded plastic parts in four colors and 2 springs, available from for $20.

You can make an extensor grabber with an extensor construction kit and a few extra parts. With this you can grab things at a distance - you can even catch a tennis ball in mid-air! The extra parts are available to download and 3D print for yourself from Printables. Or you can order the printed parts from Shapeways (the Shapeways parts will likely work more smoothly and be more durable than home-printed parts).

Caltrop retracted
Caltrop extended
X-extensor retracted
X-extensor extended
Included parts
Box and contents