Origami Koi Pond 2.0

This is the second version of the Koi Pond 1.0.

Although we liked the idea of using clock repair kit to move the fish, we noticed two problems.

1. The clock repair kit is kind of weak. It can move the fish horizontally (like on the floor), but not vertically. This means we can't hang the pond on our wall, like we were hoping to do.
2. We would like to mobilize more than one fish, but we don't have tons of random clock repair kits lying around.

·        Mounting foam board (You'll mount the origami and the . It could be wood, foam, or cardboard. Foam board is probably the easiest to handle.)

·        Decorative paper for background. (I used wallpaper)

Technical stuff

·        2 x FS90R-360 Degree Continuous Rotation Servo (one for each movement control group)

·        3D printed servo mount (or you can make one with cardboard as in my test image)

·        Arduino Nano Chip (or any similar programmable micro-controller chip)

·        Breadboard

·        Motion sensor (HC-SR501 PIR Infrared Sensor)

·        Piezoelectric Disc 

·        Wires

·        1 2-AAA-Battery holder with on/off switch

·        2 3.7volt rechargeable Li-ion batteries

·        Plastic sheets

·        Acrylic sheets

Supports

·        Wood rulers (or similar one-inch-wide thing wood strip 12 inch long)

·        Used plastic water bottles.

·        Duct tape

Optional

·        Epoxy resin

·        Velcro dots

Tools

·        Hot glue gun

·        Foam cutting tool

·        Utility knife

Origami koi fish, made here: https://www.instructables.com/Origami-Koi-Fish/

Origami lily pad, made here: https://www.instructables.com/Giant-Lily-Pad-Paper-Art/

Origami water lily, made here: https://www.instructables.com/Water-Lily-Paper-Art/

Decorate the board. I used self-adhesive wallpaper.

Mix epoxy resin according to the bottle's instructions.

Pour the mix in a ripple or wave pattern. Carefully space your patterns, as the resin will spread while it cures.

Let the resin cure for a day, or use UV light to speed up the curing.

Wash the plastic bottle and remove the label. 

Use a plastic/foam cutter to make two opposite straight openings to fit the wood ruler through, tightly. If it is too loose, use hot glue to secure. Depending on the final layout, we might have to make another pair of openings. For us, we made two supports: One with one ruler and one with two rulers.

Cut the bottle at least 15 cm from the bottom. Then cut strips at the opening as shown. 

Position the supported lily pads first. Once you've decided the layout, trace and cut holes on the board where the supports go. Put the plastic bottle through the holes with bottom facing up. Hot glue the end with splits to the board, and cover with tape.

Hot glue some more lily pads to the rulers. Then position the servo so that it can hide under those "unsupported" lily pads and freely move without hitting anything. This definitely takes some trial and error!

If you have access to a 3D printer, you can make one servo mountable base for SG90 servo with the file here. This is contributed by Thingiverse user DaveCG (https://www.thingiverse.com/thing:2377044).

Cut a strip of acrylic plastic. Mount one end of the acrylic strip on the servo as shown. Then cut the resin ripples from the plastic sheet and secure with nut/bolt on to the other end of the acrylic strip. Alternatively, if you did not decorate plastic with resin, simply use the plastic sheet directly. 

Cut out a hole on the board so the servo case of the mountable base can go through. Tape or screw the servo case on at the back of the board.

Glue the origami onto the resin ripples.

Please refer to the circuit for the wiring.

Note that I did not use Arduino UNO chip, but actually the Arduino NANO. The idea is the same, but I couldn't find the component in Tinkercad. Similarly, I used two continuous FS90R servos and replaced the power plug with 2 3.7V Li-ion battery.

In the picture of my connected circuit, I only wired one servo for testing, as once the circuit was turned on, I had to use one hand to hold the servo and one hand to test motion sensor. There are still two servos in the finished product

I used a small paper box to hold my circuitry. First, secure the box with metal wire to the back of the board. Cover up the metal wire on board with a strip of wallpaper.

Secure battery pack on the top of the box. Leave the switch accessible.

Cut a hole for PIR motion sensor and secure it with Velcro dots.

Cut holes for the wires connecting to servo motors.

Leave the piezo discs out. These turns out to be a very sensitive sensor with my threshold in the program. Any movement of the board will trigger it and cause the fish group to move. And once the fish group starts to move, it vibrates the board and hence the fish group will move again. You might want to raise the threshold in the program.

Use the rest of the resin ripples, or anything else you want to add, for decoration

·        Sound

Should introduce a circuit that plays a sound when the fish swims around?

·        Better movement

This can be easily done by slowing the continuous servo. In addition, I could probably introduce small pauses in between. Is there any other way to do this?