This is another tutorial in my series on making mechanical devices with cardboard and foam board.

We will call this the series on cardboard machines.

In a previous tutorial we looked at making pulleys and using them to change rotational speed. That tutorial is here

In this tutorial we look at how to change the axis of rotation which is a very important tool for making cardboard machines.

Here is the cardboard machine that changes the axis of rotation. You turn the handle crank at "A" and the direction of rotation is changed inside the box and the paddle at "B" rotates.

And we achieve this with a clever little device. It is simply a spring that I took from a pen. It effectively transfers the direction of rotation. And it works really well.

Here is a closer look. The spring is hot glued to each of the barbecue skewers.

An important thing to note is the four x's. These squares of foamboard act as retaining washers. They prevent the barbecue skewers from sliding in or out. They are glued to the barbecue skewers so they rotate as the skewers rotate.

The constellation machine

This is a unique machine that can be made out of cardboard or foamboard. The night sky lights up and rotates. Fun and quirky project. Watch the video here.