Introduction: Mini Shuriken Fidget Spinner

This is a simple Fidget Spinner which is able to run with only one bearing.

It's ergonomic shape and light weight makes it easy to use even with one hand and if you get hit with it it doesn't hurt.

The shape is inspired by a shuriken, so even it's simplicity it's still cool :).

Here I will show you all the steps and processes it took me to desing and 3D print this Mini Shuriken.

Step 1: Chosing and Preparing the Bearing

I start by chosing the bearing. I will be using a 608 RS bearing (abec 7). It's dimensions are:

External Diameter: 22mm

Internal Diameter: 8mm

Height: 7mm

This will have an effect on the design so it's very important to make shure which are the dimensions of the bearing before starting the design process.

Step 2: Design the Body Shape 1

The shuriken shape I was looking up to des not have sharp edges, so it should be easy and confortable to use. I got inspired by the black logo comming from google images (type: shuriken icons).

To make the desing, I use Fusion 360. I start by drawing the circle that corresponds to the bearing place.

Then I draw one arm using the tools "Line" and "circle".

With this I have the shape of one arm.

Step 3: Design the Body Shape 2

Now I use the tool "Circular Pattern" to draw 4 equal arms.

I trim off the excess lines using the tool "Trim"

Now the body of the fidget spinner starts to get the desired shape. The next step will be add the 3rd dimension.

Step 4: Design the Body Shape 3

Now, using the tool "Extrude", I pull the shape 7 mm into the Z direction

Finally I add round edges using the tool "Fillet". I only apply the tool to the curved edges, so the shape looks more familiar to a shuriken but still comfortable

Step 5: Design the Caps

For the cap design, I use a simple model which is supposed to fit inside the inner diameter of the bearing by pressure.

The mesures of the cap are:

External cilinder: Diameter=22mm, height=2mm

Spacer: Diameter =10mm, height=1mm

Internal cilinder: Diameter=8mm, height=3.25mm, Fillet= 0.5mm (radius)

Step 6: 3D Printing

For the 3D printing I used the Cura Software. My recommendation is to use the "Scale Tool" and extend the shuriken 102% in the X and Y directions, just to give some room to the bearing hole.

Once printed, the bearing fits inside the hole and the caps inside the bearing by applying pressure.

If you liked this project, you can follow me on Instagram: @project_3d_spinnerstgn. I have many other designs available.