Building a compass


  #1  
Old 12-20-17, 08:57 PM
C
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 2
Received 0 Votes on 0 Posts
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:
 
Attached Images    
  #2  
Old 12-20-17, 09:01 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,109
Received 1,510 Votes on 1,397 Posts
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.
 
  #3  
Old 12-21-17, 07:18 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,258
Received 896 Votes on 826 Posts
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.
 
  #4  
Old 12-21-17, 07:47 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,635
Received 98 Votes on 86 Posts
Magnetized needle stuck through cork was how I saw this done as a kid.
 
  #5  
Old 12-21-17, 11:15 AM
C
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 2
Received 0 Votes on 0 Posts
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?
 
  #6  
Old 12-21-17, 11:22 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,635
Received 98 Votes on 86 Posts
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.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: