Hi everyone!

In this instructable I'm going to show you how to make the Rasengan, a spinning ball of chakra formed and held in the palm of the user's hand in the Naruto manga.

It may seems complicated but..believe me! It's a lot easier that you think! It's basically a ball created by 4 bright blue LEDs that spin on two different axes of rotation thanks to two motors.

Except for the four AA rechargeable battery, I made it using just materials saved from the garbage or dismounted from broken stuff, but if you have to buy everything you will spend less than 5$.

Thanks for voting for me in the "Make it Move Contest"! I really appreciated it!!

Step 1: Materials & Tools

MATERIALS:

- 8x8cm scrap piece of plastic

- 2x (8x8x1,5cm) soft foam from packaging

- 2x 35cm velcro straps

- 2x (5x2x2cm) scrap wood

- 21cm metal coat hanger

- 4x bright blue LEDs

- 2x 3V motor

- 4x AA battery(1,5V) and 1x 3V coin cell battery(3V)

- 2x 2AA battery holder

TOOLS:

- soldering iron

- hot glue gun

- multitool (pliers and scissors)

Step 2: The Wrist Mount

First of all we need to create a mount for the wrist.

I took a scrap piece of plastic and I cut a piece of 8x8cm. Than I marked the positions of the holes for the velcro straps and I cut the 4 rectangular slots scoring the plastic with a xacto knife.

I had a couple of velcro straps of 50cm each laying around so I decided to use them. Since they were too long I cut out a piece in order to get just 35cm.

Step 3: Make It Comfy

In order to make the wrist mount more comfortable and more stable I hot glued two pieces of soft foam (8x8x1,5cm) under it. It's the material used to protect fragile things in shipping boxes but If you can't find it, you could use a sponge or something soft like that.

Be sure to insert the velcro straps in the slots created in the previous step before glueing the foam!

Step 4: The Motor Attachment(s)

In the pictures above you can see two options for the motor attachment.

I made it out of a scrap piece of wood but you could use another material.

You could mount the motor between two pieces of wood held together by two screws, or you can drill a hole 1mm smaller than the motor in order to press it inside the wood piece with a vise, a clamp, or a couple of hits of hammer.

In order to make the final product a little more stable, I took another piece of scrap wood, and I drilled a small hole of 3mm in order to push inside a piece of plastic tube. This small tube will act as a bearing, helping the motor to spin the metal wire steadier.

Step 5: Secure the 1st Motor to the Wrist Mount

Now we need to secure the motor (and the motor attachment) to the wrist mount.

Before doing it, I used the xacto knife to make some scratches on the plastic (2nd picture). This will help the hot glue to stick better to the flat plastic surface. I also inserted a straight piece of the metal wire in the motor and in the "plastic bearing" to place the wooden pieces correctly.

Once the motor is glued in place, I used again the hot glue to secure a 2xAA battery case onto it.

Finally I connected the motor to the battery case and to a ON/OFF sliding switch.

Step 6: The Metal Coat Hanger

Now we need to bend a metal wire to a correct shape. Since we need 21cm of it, I used the straight section of a metal coat hanger.

As you can see in the 3rd picture, we have to make three 90° bends; the first at 11cm, the second at 13cm, and the last one at 19cm.

Finally I hot glued a 2AA battery case on the end of the 11cm section and I twisted its wires around the remaining part of the metal wire.

Step 7: The LEDs Cross

Now it's the time to solder 4 blue LEDs in a cross shape.

The diameter of the rasengan ball it's made by the distance of the LEDs; since I soldered them 9cm apart, my rasengan's diameter measures 9cm.

You could hot glue the LEDs cross onto a small plastic gear that can be easily found in any broken toy and can be perpendicularly mounted on the motor, but since I had a small wooden knob (of the perfect dimension) laying around, I decided to use that.

So I drilled 4 small holes on the side of the wooden knob for the negative legs of the LEDs, I inserted the battery in the existing round cavity (with the negative side facing down), and I soldered the remaining 4 legs of the LEDs to a ON/OFF sliding switch after insulating the positive side of the coin cell battery with a piece of electrical tape.

Step 8: Secure the LEDs to the 2nd Motor

Now we can complete our DIY rasengan.

First of all glue the LEDs cross to the second motor, then secure it to the 2cm sections of the metal wire, and finally connect the motor to the wires that come from the 2AA battery case. (It could be useful a switch but I run out of them so I simply remove/insert one AA battery to turn off/on the second motor)

NOTE: In order to create a perfect sphere, the LEDs should line up with the shaft of the motor. That's why we bent the metal wire in that shape.

Insert the batteries, and test it! First of all light up the LEDs, then turn on the motor under them, and lastly turn on the other motor.