Science Models
Science Fair Projects

Published on Sep 16, 2023

Dog Feeder


The objective: Our experiment includes 5 simple machines there are the Wedge, screw, Inclined plane, movable pulley and the wheel and axle. Also our machine helps us feed dog food into a dog house without bending down.


The purpose of our experiment is to help us make things easier to do. We are going to combine 4 simple machines to make one big compound machine! We will explain what simple machines, screws,wedges, wheel and axle are and how it works. Don’t you think that is really exciting? Simple machines help people do lots of work or they make the work a lot easier to do!

A simple machine can be an inclined plane, lever, wheel and axle, pulley, wedge or screw. The simple machines help everyone do work. For example, the inclined plane can help us when one level is taller than another level by putting a piece of wood on top. It will help you get to the second level without lifting it. The second example is the lever which helps by turning around on a fixed point.

The screw is based upon an inclined plane. It is formed when an inclined plane and provision to turn it, is on the opposite end. They come in different shapes and sizes and their main purpose is to hold or fasten objects together and raise weights. However, a screw depends upon another machine, like a lever for its operation.

People use pulleys to move things up or down. Pulleys can help you get stuff that are in hard to reach places like if it is too high. There are also two types of pulleys which are fixed pulleys and moveable pulleys. Pulleys can also hold heavy things like a crane. Tower cranes use pulleys also. When you put a flag up on a pole it is a kind of pulley.
The inclined plane helps us move things from one level to another level or even more. An inclined plane is a kind of a pulley that you put a piece of wood on top to help you get to the second level without lifting it up or down. That is useful because you don't have to lift something that is about 100 pounds or more upstairs or anywhere else! Isn’t that so awesome!

Wheels comes in different sizes and do not create tons of friction. The axle is in the wheel and it helps it move or even work out. We use an wheel and axle to drive a car, also to move the shopping cart or even enjoy a bike ride in summer!

Friction is when two surfaces rub together. For example, if you rub your hands together you make friction and if you touch someone you might shock them. Sometimes friction stops things from going super fast.

We want a machine that helps feed your dog without the owner bending down. Our invention is a dog house and if you pull the pulley the dog's food comes out. In our invention the five types of simple machines we plan to use are a screw, a wedge, a pulley, a wheel and axle and a lever. Isn’t an awesome invention!!


• Cardboard box (that the two flaps can connect.)

• String

• dog food/bowl

• Pulley

• screw’s

• wheel

Dog Feeder


1. Find a box that is big enough to fit your dog

2. Put some fabric or tissue paper in the bottom or the box

3. Pull two flaps up in a triangle to make the roof but don’t tape it.

4. pull up a side flaps and hold it against the roof

5. trace the edges of the roof on the side flap.

6. tape the side flap to the roof

7. the other side flap completely off also cut the from dog house off so you can see right in.

8. tape the side you cut

9. Draw a shape of a door on the side you want the dog door on.

10. Then use some screws and screw the piece of cardboard to the doghouse.

11. Tie one of the top of the chopstick at were you want the dog feeders main part to drop the dog food (on the inside).

12. Then tie a another one of the top of the chopstick at were you want the dog feeders main part to drop the dog food (on the inside).


To make our dog house with the dog feeder we used a lot of different materials. We used almost every type of simple machines. The only one we didn’t use was the wedge. We found all of our materials in our houses. We used a large cardboard box to make the dog house and we cut two parts to make the roof. We used lots of duct tape to make it secure. We used the leftover cardboard to make other parts of the dog feeder. We found a massager that was like a wheel and axle to use with our pulley. In order to keep the inclined plane from not going too far, we cut the top of the chopstick to be the stopper. We were afraid that the dog house wasn’t sturdy enough so we added pieces of wood to keep the cardboard up right. We were really happy that the pulley worked consistently to raise and lower the food/bowl.


I think our hypothesis was correct because it was able to give the food to the dog. This is a very great experiment because it will help a lot of people in life. I think it will make it a lot more easier in real life because you do not need to bend as much with our dog feeder experiment. Because when you want to bend down to give the food it may hurt so the pulley takes it down for you so your back will not hurt at all. Plus I think it is very comfy for a dog to stay in. But the down part is that you can only use it for small dogs or puppies. Plus you have to change the wood and cardboard every few months. You do not need to let the dog out of the small dog house because you can leave the door open or when he did something bad and you want him to stay in their for a few minutes you can close the door of the dog house.


“Screws” Michelle Kelley

“Pulleys”Michelle Kelley

“Wedge” Michelle Kelley

Science Fair Project done By Michelle Kelley