Solana: the "SUN"flower

Project created by: Sabrina Mable, Sumaiya Sheikh, Haadiah Khan

Motivation

Do you ever feel like you are more open to the world when the sun is beaming and closed off when the world is dark? Well, so does Solana: a robotic flower that can sense the presence of light and the amount of light that there is. So, you no longer need to go outside, check your window, or your phone to see if its sunny or not. Solana will do it for you! Or so you think! Solana is for the lazy people out there that need an extra push to get outside!

Description

Our useless machine is based on the idea of a flower and its response to light. In the presence of light, the petals open up further, while the absence of light make them close up, hidden away from the world. With this in mind we used a photosensitive resistor that rotates an actuator based on the quantity of light. As a fun element, we want to double the flower as home for a miniature individual who can find some solace in their own little space, shut away from the world.

Step 1: Introducing Solana

Step 2: Material Tools and Components

List of Parts:

Electrical

- 1 x 330 Ω Resistor

- 8 x Wires

- 1 x Photoresistor

- 1 x Arduino board

- 1 x Bread board

- 1 x Servo motor (0.16sec/60 ̊, 4.8-6V, 180d)

Mechanical

- 1 x ¼” dowel

- 2 x 3mm plywood sheets (31” x 17.5”)

- 1 x Spool of Fishing wire

- 6 x Rubber elastic bands

Technical Tools:

Fabrication

- Laser cutter

- Weldbond Glue

- Hot Glue

Software

- Rhino 6

- Arduino

- Fritzing

- Gear Generator

Step 3: Circuit and Programming

Set up circuit as shown with all electrical components. Colour coordinate wires to eliminate confusion. The Arduino pins where the wires are connected to the Arduino board must correspond to the setup inputs in the Arduino code.

Download Arduino code and upload to Arduino board through cable to laptop. The following code enables the servo motor to move clockwise or anticlockwise depending on the amount of light the photoresistor receives by remapping the sensitivity of the resistor to the position of the motor.

Step 4: Machine Making - Mechanics and Assembly

Download provided drawing file containing nested laser bed files. Program laser cutter to cut all required pieces out of 3mm plywood. Use included model as reference for assembling laser cut pieces.

Start by gluing hinges to the top base piece. Sand away glue left between hinges. Cut elastic bands and use one strip each to tie one end onto each rack. Use loose end of elastic band to create a knot through the outer holes on the top base. Cut equal lengths of fishing wire (forearm length). Tie one piece of fishing wire to the other end of each rack and thread through respective hole in the top base. Carefully assemble and glue petal pieces. Cut 6 pieces of dowels to length of 2cm. Align each petal to a corresponding rack and secure in place with the dowels. Proceed to glue dowels on the outside of the hinges for stability.

THE MOST IMPORTANT PART: Glue Solana (the fairy) into the center of the top base.

Time to construct the interior mechanism. Glue the three pieces that make up the stand for the gears and motor together. Cut a 5cm dowel and glue it into the circular hole in the stand. Stack four washers onto the dowel and glue in place. Insert the larger gear through the dowel and glue a final washer around it to hold the gear in place. Glue the stand to the bottom base. Consult model for guidance. Connect smaller gear to the servo motor and hot glue into rectangular slot in the stand. Make sure to align the gears. Tie loose strands of fishing wire protruding from the top base into a knot around the larger rack. Hot glue the knot for extra security and cut off excess wire. Glue three pieces that make up the rack slider together and sand down dried glue afterwards to reduce friction. Place rack into slider and align with gears. Glue slider onto bottom base. Enclose two sides of the bottom base (the side behind the stand and the side adjacent on the left).

Stick breadboard (remember you already made that!!) to the back wall of the base. Glue the top base to the walls of the bottom base. Insert photoresistor through the circular hole in the corner of the top base. Once wires are organized, glue the side with the opening to the base, ensuring wires go through this opening. It is your decision whether to display the interior mechanism or enclose it with the fourth side of the base.

Step 5: Review and Reflection

As demonstrated in the progress photos of our concept sketches we spent a long time planning out the gear mechanism for controlling the opening and closing of the flower petals. The original design mechanism we came up with was successful and worked as expected. However, some adjustments needed to be made to in order to ensure it functioned accordingly.

Originally, the servo motor was attached to a large gear, controlling the system by rotating a small gear which moved the rack up and down to guide the motion of the petals. Instead, we switched the placement of the gears so the servo motor is attached to the small gear which rotates the large gear and controls the movement of the rack. This was because the servo motor only rotates 180 degrees so the second gear required to move 1/4, meaning the ratio proportions needed to change. Once the gears rotated properly, we discovered that the servo motor did not have enough torque to move the petals so we replaced it with a motor that has 3 times as much toque. At first the Arduino code was programmed with incorrect direction of motor rotation. In order for the petals to open with light we determined that the motor must be programmed to rotate clockwise, causing the large gear to rotate counter-clockwise and the rack to move downward, opening the petals. For the absence of light the motor must be programmed to rotate counter-clockwise in order to have the opposite effect. When assembling the rack pieces and associated components we realized sanding them reduced friction and enabled smoother movement. Attaching the elastics in a position that would control a balanced opening and closing motion took a trial and error process. Overall, the entire project required a process of trial and error in order to properly construct the mechanism, including multiple trips to the laser cutter and constant testing of the petal movements, gear assembly and electrical wiring.

Based on what we learned from this process we would include calculations of torque, rotation and dimensions in our initial conceptualization stage to reduce amount of material waste and laser cut time in physical construction. To upgrade the project we would use a more sensitive photoresistor or incorporate a potentiometer to detect more subtle light (such as sunlight). We would also design a second mechanism to control the movement of Solana (the fairy) so she could provide some secondary movement as well.

Step 6: References and Credits

1) Sumaiya Sheikh, Haadiah Khan and Sabrina Mable for making this project.

2) UGEARS. "Model Mechanical Flower." in Mechanical Models PDF Instructions, UGEARS. Accessed on March 1, 2020. https:// ugearsmodels.com/instructions/Mechanical-Flower.pdf? fbclid=IwAR02B6T0USmrKZ0GFxie8oV_S6Wl0ImMkHqFZsFc60q0Si5yKZE 6hCECfzE

3) Maria Yablonina for assisting with Arduino code and gear ratio understanding.

This project was a part of the Useless Machine assignment for the Physical Computing class at the Daniels Faculty within the University of Toronto. :)

Thanks to you for choosing Solana!!