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Toothfloss(Toothbrush+floss)

Name: Claire Kim

School: Stonegate Elementary

Teacher: Ms. Martin

Problem: Public restrooms need more efficient flushing systems because most people do not flush the toilet after using the bathroom.

Automatic flusher(mechanical)

Automatic flushing toilet(sensors)

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Abstract

People oftenly do not flush their toilets in public restrooms, leaving off a smelly odor in the bathrooms. Recently, my friend has complained about dirty restrooms in her school, due to people not flushing toilets properly. To fix this worldwide problem, I planned an automatic flushing system powered by a simple machine: pulleys. I created 2 designs for the prototype and tested each one by pulling on the lock(tied with dental floss along with the pulleys) to observe if the handle had any movement.

My first design did NOT meet the requirements, failing to operate the pulley system. However, my second design worked well, reaching my requirment for better performance. The handle moved about 1-2 cm, showing better results than the first design. This means that the pulley system successfully transferred motion energy to the handle. It also met my constraints of being able to be finished by the deadline, December 3rd, and not being over the budget $20.

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Introduction(Background Research)

In the U.S., 7% of the population rarely flush or never flush the toilet(today.yougov.com). Nowadays, hasty people they don’t consider flushing the toilet as “necessary” work, leading to occasional smelly and dirty public restrooms.

Many solutions of this issue was made, including the automatic flusher, one of the successful solutions of the problem, although it had its issues. Automatic toilet flushing is operated using infrared light technology, detecting any movements, flushing the toilet when the people get out of the toilet(tap.sensor.com). In certain cases though, when people stand up to use toilet paper, the toilet immediately flushes the water away, wasting water. As a result, according to a 2010 data, water wasted from toilets has increased 54 percent from automatic flushing, 807 gallons to 1,234 gallons daily(grist.org). Additionally, automatic flush systems are not installed in most public places, due to their expensive electric fees, maintenance fees, and repair fees.

Criteria:

Less maintenance expense than previous system
Better accuracy and performance

Constraints:

Project’s due date: December 3rd, 2024.
Cost: up or less than $20-$30.
Quantity of materials selling in stores

The system would ensure ongoing perfect accuracy without issues.

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Engineering Solution: Prototype/Model

Model of automatic toilet system: Design #1

The model consists of materials available at home, or bought from Amazon. From my research at britannica.com, simple machines can help reduce effort for movement, so I decided to use the pulley system to transfer mechanical energy to the toilet handle, gaining mechanical advantage(putting less strength for motion). Additionally, based on theengineeringchoice.com, I learned that compound pulleys(a combination of fixed and movable pulleys) can reduce the weight of the object ½ times, making it easier to lift up the handle just by opening the lock. For the bathroom stalls, I created it with blocks of styrofoam, a material soft enough to insert the pulleys, but not too flimsy. The styrofoam were taped onto the chopsticks, the part that acts out as the base of the model. Lastly, the toilet handle(small piece of chopstick) is secured onto a larger piece of chopstick, representing the toilet flusher.

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Materials

130 cm of strong elastic cord
5 plastic pulleys with holes(20 mm)
2m of double-sided duct tape
4-5 chopsticks
5 styrofoam sheets(11cmx11cm)

Elastic Cord

Plastic pulley wheels

Duct Tape

Styrofoam sheets Chopsticks

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Procedure(Instructions)

Gather all the necessary materials.
Create a model using the chopsticks. For the stalls, cut 2 pairs of chopsticks into halves. Arrange the chopsticks by taping them into a rectangular prism-like shape, but without inserting any chopsticks on the top.
Put a thin layer of styrofoam under the model, then cut ¾ of a chopstick to stick into the styrofoam, and tape the remaining ¼ onto the ¾ -length chopstick to model as the handle(for the flushing system).
Wrap a long piece of styrofoam around the chopsticks, securing it with tape on the ends to fit perfectly. Do not insert the front stall yet.
Punch a thin, long hole on the front styrofoam stall to create the hole for the lock. To create the lock, cut pieces of a 2cm chopstick and a 2 cm toothpick. Tape the toothpick horizontally next to the chopstick, then insert it into the hole.
Insert the first pulley wheel(using a toothpick fitted inside the hole of the pulley) approximately 4 1/2 cm apart from the lock into the styrofoam. Cut the remaining amount of toothpick sticking out, then push it all the way and secure with tape. After, remove the pulley wheel, put a piece of tape on the hole, and reinsert the pulley through the hole to make the pulleys unmovable.
Insert the second pulley 3cm down and 2cm right from the first pulley(repeat the inserting steps from step 6)
After, insert the third pulley 3cm upwards and 5cm to the right(also repeat inserting steps from step 6) T
Create a block & tackle pulley format by inserting a pulley 2 cm apart from the toilet handle and inserting an another pulley 2cm beneath the pulley(repeat inserting instructions from step 6)
Tie the elastic cord on the lock. After, thread the elastic cord into the sides of the pulley wheels to create compound pulleys(for the first three pulleys). Thread the elastic cord on the chopstick. Thread the cord into the holes of the two pulleys, then wrap it around the pulleys.
Tie the remaining cord on the ¼-length dowel, or the flushing handle.
Tape the front stall onto the right stall, but not securing the left side of the stall.

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Results

Result for Model #1: Results for Model #2:

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Revised Solution and Prototype/Model

In total, I created and experimented with 2 designs.

For my second experiment, I changed the operator(the elastic cord) to dental floss, based on my data collected for my first design. The first design was unsuccessful, failing to reach my standards I set, which was being operable and being a better option than automatic flush systems. This was due to the elastic cord not having any effect on the pulley movement, only extending when pulled back. Also, I wrapped duct tape around styrofoam, then recut the holes made previously to prevent any damages to the styrofoam, a fragile material. Then, the toothpicks were revised to paper clip wires to make the pulley rotate alone, not with the toothpick. After these changes, I repeated the same procedures for the previous design.

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Discussion

By the end of testing, I analyzed data gathered from the experiment, which showed that Model #2 significantly met more requirements and constraints than Model #1.

Model #1

Model #1 did not meet my requirement of better performance and accuracy because the pulley system did not operate properly. As a result, the distance of the handle’s movement was 0 cm, not having any impact on the motion of the handle. To create a successful model, I replaced few parts of the model, which were the elastic cord, the handle, and the toothpicks securing the pulleys. For the pulley system to activate, the elastic cord was replaced by dental floss, and the toothpicks were also restored by paper clip wires.

Model #2

Model #2 successfully met my expectations and my constraints, making under the the budget of $20. The dental floss prosperously activated the pulley system, rotating the pulleys to transfer energy to the paper clip wire handle. With some force pulled on the lock, the handle pushed up 2cm by the mechanical energy transported from the pulleys. If this system was applied onto a real public bathroom, it is most likely to successfully flush the toilet when opening the door.

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Conclusion

From this project, I learned that pulleys are great tools used for mechanical advantage, a term for putting on less effort for a motion. However, pulleys only work when inserted and manipulated correctly. The original prototype failed to reach my qualifications because for 2 reasons:

The toothpick rotated with the pulley, making it easier for the pulley to fall out of the styrofoam.
The elastic cord operating the system didn’t do its role; it only extended instead of helping to revolve around.

My second prototype was full of revisions from the previous prototype, with a new string, a new handle, and a new attacher for the pulleys. These improvements extremely upgraded the prototype, with a finer and smoother operation. With appropriate steps of incorporating and utilizing the pulley wheels, the automatic flushing system has been a success.

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Reflection/Application

From this engineering project, I learned that pulleys can outstandingly transfer energy for notable motion, depending on the placements of the pulleys. For my experiment, I noticed compound pulleys had more mechanical advantage than fixed or moving pulleys, and a block and tackle can lift up heavy weights and is beneficial for transferring energy to different directions. When connecting the pulleys together, I believed that any type of string with rubber(for this prototype an elastic cord) could operate the system properly. However, I was proved wrong when I tested out my first design, for the elastic cord did not change any data at all, meaning that the handle did not move a bit.

This prototype would greatly impact the world, for it is a good solution of automatic flushing that saves water, plus not being over the budget. If this design is on a trial to be applied in real life locations such as malls and stores, it would also be very pleasing to the people, for they could save time flushing the toilet and not get exposed to bacteria touched on the handle.

My next questions are: How could this prototype improve more? How could it operate with even less force? To do this, I believe that the quantity and the size of the pulleys would have to be increased, for these variables affect how much force is needed to operate the system. As I stated previously, the arrangement would be important too, also a key part of changing the amount of effort put into to make the prototype work.

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References Cited

Bialik, C. (Ed.). (2023, February 15). Toilet talk: Polling American's potty preferences. YouGov. Retrieved February 15, 2023, from https://today.yougov.com/society/articles/45245-toilet-talk-polling-americans-potty-preferences

KEGE. (n.d.). What is automatic toilet flusher and how does it work. KEGE. https://www.tap-sensor.com/blog/what-is-automatic-toilet-flusher-and-how-does-it-work.html#:~:text=2.-,Solenoid%20valve,sensor%20control%20the%20solenoid%20valve.

Umbra. (2015, September 24). Are automatic toilets wasteful? Grist. https://grist.org/living/are-automatic-toilets-wasteful/

Augustyn, A. (2024, October 21). Simple machine. Britannica. https://www.britannica.com/technology/simple-machine

Sabhadiya, S. (n.d.). What is pulley? The Engineering Choice. https://www.theengineeringchoice.com/what-is-pulley/

I thank my parents for suggesting this idea, or topic for me to work as my science project. I am also appreciative of my science teacher, Brandynn Martin, who gave me advice for engineering my prototype and collecting useful, scientific data.