Pyramid Levitator

Pyramid Levitation System - How it works:

The Pyramid Levitator uses two Piezo ultrasonic transmitting speakers pointing towards each other. The opposing beams of 40kHz sound waves create what's called standing waves and pressure nodes. Small items will levitate at those pressure nodes due to the acoustic radiation pressure. Acoustic radiation pressure is the physical pressure that a sound wave can exert on a surface, in this case balancing the pull of gravity and causing levitation.

In the picture is a piece of styrofoam being levitated.

The Pyramid has an LED on top that slowly changes colors and illuminates the floating objects.
There are no magnets, just ultrasonic sound to do the levitating.

There are only a few main components to the simple design. You just need to connect and/or solder those main components together and install them inside the 3D printed case.

The Pyramid is Micro-USB powered using your phone charger or computer.

Turn on and off the Pyramid by pressing the big power button in front. Then just slip a small item between the speakers and levitate!

Parts needed:

M2 x locking nut x 7

M2 x 12 bolt (phillips) x 6

18 gauge wire x 1 foot

LED - multi color x 1

Micro-usb module x 1

LN298N amp x 1

Frequency Generator x 1

40khz Piezo element x 2 Transmit "T" only, not the Receive or "R" marked ones.

power switch x 1

wire 22 gauge x 40 inches - Referenced as "wire". When split, will reference as "single wire"

Micro-USB cable x 1

Bottom Case Screws x 5

Micro-USB screw x 1

FG to Amp pin connectors x 2

Tools you will need:

Soldering iron.

Solder. Suggested - 22 Gauge, Sn63/Pb37, Ra Flux.

Small phillips screw driver and T-5 torx bit.

Small 4mm nut driver.

Wire cutters/strippers -

Hemostats are very helpful to hold one 4mm nut that's in a tight corner.

There are three main parts to print, plus a mini tool to help place the levitating object into place.

1. The main body

2. The top speaker holder

3. The bottom

4. A little tool to help place the levitating item between the speakers. Just cut a square piece of window screen type material big enough to fit in between the two 3D printouts and with an epoxy type of glue stick it all together :)

1. Cut a 6 inch length piece of 22 awg wire.

2. Strip 1/4” of both the black and red wires on one end and strip the other end 3/8” each. Solder the two 1/4” striped ends to the switch.

3. Install the switch into the Pyramid main body, use a washer and tighten the nut on to the switch.

Using two wires with pin connectors (I used the female end wires from Amazon cut in half), insert a darker color wire into the GND and lighter color wire into the PWM connector on the Function Generator from the bottom side. Solder the two wires in place on the screen side.

Cut a 5” piece of 24 gauge wire and strip ¼ inch from both wires on one end and 3/8 inch on the other end. Solder the red wire to the VIN+ and the black wire to the VIN- using the ¼” stripped ends. Solder the two wires in place on the screen side.

Cut a 5 inch length piece of single red 22 gauge wire. Strip one end of the wire about 1/4” and the other end about 3/8”. Push the ¼” stripped Red end into the Micro-USB’s VOUT+. The wire should be entering from the top of the board.

Then turn over the board, and solder the red wire in place.

Solder the Pyramid switch's RED wire (-) into the MicroUsb’s OUT-

For levitating, we need two Transmit Piezo speakers. They will be transmitting their audio waves at each other.

Transmit Piezo #1:

Cut an 8” piece of 22 gauge wire and strip ½” off the ends.

Solder the red wire to the Transmit Piezo speaker’s positive pin with the brown circle at the base (or other marking). Solder the black wire to the negative pin of the piezo speaker. Thread the two wires through the top of the main Pyramid body, and lower the speaker into place (first two pics).

Transmit Piezo #2:

Using two single pieces of 12” x 18 gauge wire, guide the wires through the top little 3D printed Piezo holder. Strip the ends and solder to the second Piezo Transmit speaker. This is a little more difficult to solder. You have to keep the wires straight. So, tin (pre solder) the wires and pins with solder, then hold the wire to the pins and solder together. Red wire goes to positive (possibly a brown circle insulator/marking).

Pull the red and black wires up while pushing the Piezo speaking into the top piece. Everything should fit nice and snug.

Mount the Piezo speaker top piece and route the red & black 18 gauge wires through the top two holes on the Pyramids back side.

Install the LED into the Pyramid. Push the black and red wires down through the top led holes located next to the bottom piezo speaker.

Next install the Micro-USB power circuit into the Pyramid's lower back corner by snapping the board in place.

Make sure you can see the Micro-USB's voltage adjust screw inside the center of the Pyramid's main body voltage adjust hole.

Secure with a 30mm bolt and nut feeding through the hole next to the voltage adjust screw (optional).

You can always test the voltage coming out of the MicroUSB board from the two test holes on the bottom of the Pyramid.

Using four 2m x 12mm bolts and 4 x self locking nuts, install the Function Generator to in the Pyramid.

Twist the 3 Negative wires of the Function Generator, LED and Switch together.

Twist the 2 Positive wires of the Function Generator and LED together.

Connect the two Piezo speakers together in parallel by twisting their red and black wires together and solder the the connections, then trim the ends. See circuit diagram.

Insert the Positive Piezo wires to Out3 and the Negative Piezo wires to Out4, tighten the connection screws.

Install the Function Generator and LED’s Positive wires into the +5 volt connection, tighten screw.

Install the 3 twisted together negative ground wires into the GND connector and tighten screw.

Install the single 12v wire from the Micro-Usb port to the +12v connector on the amp and tighten screw.

Plug the black or darker color connector from the function generator into the IN4 pin on the L298N AMP, and plug the white or lighter color wire from the function generator into the IN3 pin on the L298N AMP.

See the diagram picture for reference.

Plug in the unit and make sure the main LED lights up, the amp’s red light is lit and the Function Generator is on.

Unplug the unit, install the L298N into the Pyramid with two 2mm x 12mm screws and nuts.

Install the bottom piece with 4 small wood screws.

The 3D printable "tool" is for placing objects to be levitated into the Pyramid. Find a small 1" square piece of window screen and glue between the two tool pieces. See the main video for a demonstration of the tool.

On the front panel of the Function Generator, there are 4 buttons. The first two are frequency up/down and the next two are duty cycle up/down.

Turn on the Pyramid and tune to around 40khz and set the duty cycle to 50%.

If you have difficulties levitating a small piece of foam, please see the Tune the Pyramid video.

Have fun levitating!

Please vote for this project in the Plastics Contest.

Thank you.

Joe