Building a compass

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  #1  
Old 12-20-17, 08:57 PM
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Building a compass

I am making a pirate outfit and 1 step for that is building a compass that I can hold in a belt. So first I tried putting small neodymium magnets in the center of a plastic cap. I got it to float but I noticed that momentum, especially rotational momentum, made the magnets sink.

Then I tried using a longer but not as strong magnet with a ball at the end. It will point north but the side with the magnet sinks. Plus, the cup I am using(which has a clear lid so that I can see the compass needle and what direction it is pointing) is too small for the long magnet.

Here are the cup and the the magnets I tried to use:
 
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  #2  
Old 12-20-17, 09:01 PM
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Welcome to the forums.

Interesting project.

When I made a compass I used a steel needle and magnetized just one end of it.
You need an axis to hold a needle in place.

Going to have to think on that one. The others will add their opinions too.
 
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Old 12-21-17, 07:18 AM
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If you are just making it for a costume there is no need for it to work. Just make something that looks like you want.
 
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Old 12-21-17, 07:47 AM
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Magnetized needle stuck through cork was how I saw this done as a kid.
 
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Old 12-21-17, 11:15 AM
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Yeah well I tried with a magnetized needle and it always sank which is why I wanted to do it with magnets. Plus how many times would I need to move the magnet across the needle to magnetize it strongly enough to point north?
 
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Old 12-21-17, 11:22 AM
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Right, metal tends to sink in water which was why we put it through a piece of cork and floated that. A small piece of metal like a needle gets magnetized pretty quickly.
 
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