Tuesday, February 09, 2016

The $0.72, Indestructible Compass

I've always liked carrying a compass on my keychain, but as I recently noted, delicate instruments and front pockets don't mix. While the TAC Compass I'm currently carrying seems to be holding up, I'm already thinking about the day when it fails me.

Inspired by this now defunct magent compass, I got to thinking: what if instead of carrying a compass I carried a high powered magnet and a way for it to pivot? That's really all a compass is, as a magnet will naturally point North/South if given the chance. So taking a cue from a project like this one, I picked up a 10 pack of 4x8mm Magnet N35 Rare Earth Neodymium magnets from eBay.

When they arrived, I put a piece of dental floss between two magnets, and like magic, the magnets aligned themselves on the North/South axis. I added a bit of red nail polish to the side that points North, and my "compass" was basically complete. The neodymium magnets are remarkably strong, and even with a twist or two in the dental floss, they'll hold their North/South position. The dental floss is optional, as long as the magnets can freely position themselves, they'll show you North; like using the old leaf floating in water trick.

This is all well and good in my kitchen, but I was obviously curious how this setup would perform in the great outdoors. So last night, while on my run, I stopped to take take some readings. It was cold, dark and windy. For reference, I dropped my Metro compass on the grass and shot a photo:

North is to the left. Then I dangled my magnet compass. I helped steady it, and even then, it took a few moments before it settled on a location:

And sure enough, the red dot is pointing left, or North. That's good. Sure, it's far from precise, but it did get the right general direction. And then I snapped a photo for reference. That's the Washington Monument off in the distance, and I'm standing between the Marine Corps Memorial and Arlington Cemetery:

And this is why I need to carry a compass: with every fiber of my being, I was absolutely sure that both compasses were wrong, North was obviously straight ahead. I know this because when we drive North to Baltimore we often head through DC. That's just simple reasoning. And it's also 100% wrong:

The above is a screenshot of Google Maps, where North is up. You can plainly see that I was facing East, as both compasses were trying to tell me. Like I said, I just need to carry and trust a compass.

What the magnet compass loses in terms of accuracy it gains in terms of durability and cost. I picked up 10 magnets for $3.60, which means that each compass is a $0.72 investment (not including the dental floss; you do floss don't you?). For now, I've stashed the magnets in my Chap-Kit, they fit in there effortlessly. Given my terrible sense of direction and how compasses tend to go on me at the most inopportune times, I may start carrying this little magnet setup as a backup. Either way, it's a nice little tool in the toolkit.

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