Introduction: Compass From a Coffee Cup

Picture of Compass From a Coffee Cup

 Lets imagine that you have just bought your favorite cup of coffee. You're in bliss right? But then, you are so taken up with your coffee that you wander out of town, and you are now in the middle of nowhere and wondering what to do. So, you whip out that used coffee cup and make a compass!

This is a surprisingly simple project, and is very fun to do. For those of you who have children, this would be a good beginner's science project. This project can also prove useful (despite the silly scenario I gave you). 

Let's begin...

Step 1: What You'll Need

Picture of What You'll Need

 To do this, you will need:
A coffee cup
A sewing needle
A magnet
Cork
Water

You will use:
Scissors
Tape

Step 2: Make the Vessel

Picture of Make the Vessel

 The coffee cup will be the vessel for the project. It will hold the water and support the compass. 
First, draw a line about 1 inch from the bottom of the cup around the cup. Then cut the cup so that you have an inch of cup wall left. 

Step 3: Magnetize the Needle

Picture of Magnetize the Needle

 This is perhaps the most important part. In a regular compass, the needle always points north. To replicate this, we must change the polarity of the material and rearrange the order of the atoms of the needle by magnetizing it to point north. 

Place your magnet on a flat surface (table) and slowly pull the needle across it on the north side of the magnet. To get any effect, you must repeat this at least 20-60 times. You get more of an effect if you repeat the step more, for example, 100 times is better than 50. 

Step 4: Floater for the Needle

Picture of Floater for the Needle

 Use the scissors to cut a small amount of cork, about 1/8 of an inch in size. Then tape you magnetized needle on top.  We're ready to go! 

Step 5: Finish Up

Picture of Finish Up

 Fill the cup with water so that it is almost full. Then gently place the bit of cork and needle in the middle of the cup. Give the compass a little bit of time to settle (make sure it is lying on a level surface). The needle should point north. You can check its accuracy with a regular compass. Have fun navigating with your new compass!

Comments

ericscrum (author)2010-05-11

Yeah, it works pretty well if you can balance the needle properly. You could also find a needle that isn't made of steel. You can see that it works in my picture of the coffee cup compass alongside a regular compass. They both point north. If you want to read up on magnetizing metal, then you can look here:

http://en.wikipedia.org/wiki/Magnet

sfcsarah (author)2010-05-10

 most needles are made of steel, and are really hard to magnetise using a permanent magnet. Does it work?

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