5 Ways to Reuse Plastic Bottles

This is 5 ways on how to convert plastic bottles into useful things for nature.

So how did I come up with this?

I’m a 9th grade High School Student. When I buy hot lunch, we get water for our drink, and it comes in a plastic bottle. When I was done drinking it, I went to throw it away and I saw lots of bottles in the trash. I realized that there should be other ways to reuse these. So I decided to figure out 5 ways to reuse water bottles. To celebrate Earth Day, I figured out 5 ways to reuse water bottles for nature and now you can too!

I had 3 main constraints to this challenge.

1. I wanted at least 3 of these ideas to work for everyone (that meant no 3d printing and simple supplies)
2. I wanted 5 different ways to reuse the water bottles
3. All of the ideas needed to be reused for nature

(Sadly I live in the north so summer is just starting. That’s why it looks like I barely have any plants in my photos, but these are some great ways to reuse bottles and help your plants at the beginning of summer).

Each project needs different supplies.

1. watering bottle
2. bottle
3. drill
4. scissors (recommended) or exacto knife
5. bottle
6. green house
7. bottle
8. scissors (recommended) or exacto knife
9. plant pot
10. bottle
11. scissors (recommended) or exacto knife
12. soil
13. string
14. drill
15. plant seeds
16. Bird feeder
17. bottle
18. 3d printer
19. scissors (recommended) or exacto knife
20. Bird food
21. drill
22. string
23. auto waterer
24. bottle
25. 3d printer
26. optional - scissors or exacto knife

To create all of them, here are all the items you would need this is what you need:

1. 5 bottles
2. drill
3. string
4. scissors (recommended) or exacto knife
5. soil
6. plant seeds
7. 3d printer
8. bird food

If you don’t like your bottle texture, and would like smooth bottles, you will also need:

1. Heat gun
2. Safety gloves (required)
3. Safety glasses (required)

you can download the fusion 360 file and the premade stl files underneath

If you don’t like the water bottle texture, you can smooth it pretty easily.

You need to be very careful in this process because you are creating pressure and heating plastic.

Make sure to wear gloves and safety glasses. (When heating it up it gets VERY hot!)

1. First you need to get a few drips of hot water and put it in the bottle. Tighten the cap on the bottle.
2. Use the heat gun to slowly and carefully heat the bottle. It will start to form steam and pressure. That means that when you heat up the plastic it will soften and smooth out. Heat up where you need to smooth. Do not touch the bottle with the heat gun.
3. Remember that there is pressure so if a hole forms you will hear the hissing of air coming out. Don’t be scared!
4. Once you are finished smoothing it out, remember these extra safety tips:.
5. Don’t instantly cool it down with cold air or water. Be patient and let it cool on it’s own for several minutes.
6. Be careful when you release the cap because there will be a lot of pressure built up.

I decided to use Fusion 360 to make some custom parts for my water bottles. Fusion 360 is a great free application that feels like it is a professional commercial platform with really high standards. If you’re a student, you also get access to the full Fusion 360 platform for FREE!

I modeled a bird feeder and a soil waterer. If you wanted to create your own design or invention, there is one thing that is critical. Use this bottle screw template file to make the interface with the bottle.. I want to give a huge thanks to Sashasaf for providing an editable file for free. (He gave the templete for the bottle cap threads).

I designed this to be parametric which means that you can change certain variables. It’s pretty easy. All you need to do is change the size and print it! I have a video on how to change whatever you want if you want different size.

Heres how I designed the soil water. First I created a plane at a certain height and lofted the thread cap to the the small circle. Next I extruded holes and cut the cone shape. Finally I drafted the thread cap at 45 degrees to make a little holder and at 45 degrees so printers can print it easily.

to make the bird feeder I created a circle for the bottom and extruded it. I then added the rim and a few holes connected to the thread cap for allowing seeds to fall.

If you want a very detailed guide on how I did it you can look at the timeline I created since I provided the editable Fusion 360 model.

Parametric Names & What They Do

• height - changes the height of the soil waterer
• id - the inner diameter of each hole in the soil water
• bird_floor - the diameter of the floor for the food
• seed_size - measure the seeds with a ruler (go a little bigger because it doesn't need to be exact)

This is probably the most simple project. All you need to do is drill the cap. Add a few holes but don’t have them be too close or else you may break the cap.

Make sure that you see the image on what orientation to drill. Place the top of the cap on the surface you will be drilling into. This orientation will prevent the cap from breaking when drilling.

I used a 1/8in (≈3mm) drill bit and I drilled in a circular pattern.

See the phots for the pattern I used. There’s no exact science to this, but I like to make things symmetric!

The green house is another pretty simple project.

There are 2 steps for this. First you need to cut the bottle (I decided to first smooth the bottle). You can use an exacto knife or scissors and remove the bottom. Lastly place it over the plant. Open the cap if you want to vent it a little. Vent it if it is really hot or moist.

The plant pot is probably my favorite because of how easy it is and how it lets you actually see the roots grow over time.

There are hundreds ways to do this. You can see some other ideas here. I decided to do 2 ideas.

1. This one is a wall art plant. The way to do this to cut on the side of the bottle and drill 2 holes between the cap and the bottom of the bottle. Finally just add some string and tie knots to prevent the string from slipping out of the holes and hang it.
2. This one is made for indoors. First you need to get a bottle and some scissors and remove the top. You can also drill a few holes, but then you will need to have a plate for prevent the water from going everywhere. Then you just add soil and seeds.

Now watch it grow and see what is usually hidden underground!

The bird feeder will require a 3D Printer. If you don’t have one, you can always see if a friend has one, or maybe even your school! First download the file in the supplies and print it. It doesn’t need any supports.

Drill 2 holes in the bottom of the bottle. (See the photo for reference, red circles are where I drilled).

Insert the string into each hole, and tie it together. I triple-knotted it to make sure.

Now add the bird seed into the bottle.

Once the print is done, screw it in, replacing where the cap was.

Sit back, and watch all the birds eat the food.

(It’s still kind of cold here, so not many birds are out.)

The auto waterer will also need 3d printing. Download the file in supplies and print it. Depending on how you change it you may need supports. The way this works is due to the holes being so small it slowly drips water. If you are printing my exact design, you shouldn’t need supports.

Next (and this is optional), but you can cut a hole in the bottom of the bottle like the greenhouse if you want it easier to refill the water. However, you may lose water faster due to evaporation. Next just screw it on. If there’s no hole, make sure that you fill the bottle with water first. You may need to shove the soil waterer deep into the soil. You can try and have it water over time or you can use it to water deep in the soil. (If you didn't remove the top, you can see bubbles enter as the water drains.)

You may have to experiment with the size of the holes in the 3d print for your soil type and watering needs.

Thank you for making it this far and reading my entire Instructable!

I hope the next time you go to throw away a plastic bottle, you stop, and instead decide to reuse it using one of my ideas or a new one of your own!

I would love to hear your comments, questions, or improvements.