Have you ever noticed any similarities between bar stools, lazy Susans, and the fidget spinner ( one of the most popular toys on the market only a few years ago ) ? They all are capable of rotating freely. So, how is this possible ? In fact, physics can be used to explain how these devices work. Ball Bearings is the common mechanism in all of them. For something that rotates or spins, ball bearings are important. And for today’s science project, we wanted to create a rotating ball bearing model out of common household materials.
WHAT IS A BALL BEARING
Let’s try sliding a block of wood across the floor. Then do the same with a marble. I am sure the marble goes farther. This is because rolling motion creates less friction than flat surfaces rubbing against each other. Ball Bearings work on the same principle. A ball bearing is a friction reducing mechanism made up of a ring-shaped track of freely rotating hard steel balls. The ball’s sphere shape reduces surface contact and friction while keeping the moving parts apart. A ball bearing has three primary functions: to support loads, minimize friction and position moving machine parts.
- Bottle Caps of Different Sizes
How to make the Ball Bearing Model
- Take three bottle caps of different sizes.
- Place the smallest cap inside the middle size cap.
- Take same sized marbles and place them between the edges of the two caps. It will now look like a ring of marbles.
- Place the largest cap such that it rests on the marbles only and does not touch any of the other caps or any other surface.
- This is a model of a ball bearing.
Test Your Model
Keep a book on the largest cap and spin it. The book will turn easily.
Now, take out the marbles. Keep the top cap back and place the book on it. try to spin the book again. It will not spin. It may move a little.
Do you know why ?
The Science behind it
Ball Bearings are required in machines to maintain a smooth flow of motion and minimize friction. Friction is simply the resistance to motion that occurs as one object moves in relation to another. Many Toys, common appliances and electronics that can rotate or spin use ball bearings.
The marbles in our ball bearing model serve as steel balls in the bearings. By having smooth marble balls and a smooth inner and outer surface for the balls to roll on, the friction between the surfaces is greatly reduced. Furthermore since, the contact area between moving parts is so limited and the balls rotate, the friction is further reduced. These marbles bear the load of the top lid and book , allowing them to rotate freely.
Additionally, there are some more science experiments for kids to understand how things work.
- How Maglav Train works
- ElectroMagnetic Train Model
- DIY Plastic Toy Car Using Wheels and Axle – Simple Machine Model
- DIY Leprechaun Trap Using Pulley – SImple Machine Model
( Disclosure : Some of the links below are affiliate link, meaning, at no additional cost to you, I will earn a commission if you click through and make a purchase )
Check out Thames and Cosmos Simple Machine Science Experiment and Model Building Kit if you want to investigate, build and learn more about simple machines and how they make complicated tasks simpler. There’s a step by step instruction manual for building a variety of simple machine model, as well as scientific explanations for each one of them.
I’ll like to hear how you make science fun for your kids.
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Till then, Happy Experimenting !