Compass Table

One day I was playing around with a compass and a magnet noticing how much fun it was to manipulate the compass rose as I moved the magnet around.  I'm of the mindset that when it comes to fun, more is usually better, so I rounded up 500 compasses and some rare earth magnets and decided to turn what started as just a little silly but entertaining play time into an actual piece of furniture.  

The compasses are inlaid into a custom table top underneath a piece of glass.  The coasters were made to match - they also provide an inconspicuous home for the powerful rare earth magnets that affect the compasses. 

Now I always know which way is north, and exactly where my cup of coffee is...er, so long as it's always on my compass table.

**Note, the reliability of compasses in mass quantities and close proximity decreases somewhat since compasses themselves are magnets.  It still works, and actually results in some pretty cool patterns, but if you're looking for the table to be 100% accurate, I'd recommend not designing a table that places them so closely together.  I'm a big fan of the way the table came out, as it's a toy just as much as it about the science of magnetism.**

Step 1 Materials

To make a compass table you need supplies for the top, the legs, and the tools to put it together.

Table

• 12mm sanded plywood
•  table legs - I used 4 Ikea Vika Oleby prefab legs
• 16 7/16" x 1/8" thick glass circular top (I had this custom cut)

Coasters

• a couple square feet of 6mm sanded plywood
• 2 cork coaster inlay
• 2 rare earth magnet

Compasses

• approximately 500 "mini compasses".  I got mine for around 20 cents a piece off Ebay.  It takes 500 20mm compasses to cover a 16.5" circle - crazy I know!

Tools

• router
• circle jig
• drill
• wood glue
• brush
• polycrylic - water based clear satin wood finish
• speed square
• clamps
• random orbital sander

Comments

[christyoates]

This is fantastic Noah, great video too!

[playful-geometer]

I saw this on a TED talk about the importance of sabbaticals, I wonder, are you that guy or did you both come up with the same idea ? I heard about an interesting phenomenon of Multiple Discoveries in a recent talk by David Wilcock

[Infinite_minus_zero]

:D awesome! at first i thought it was a giant compass as a table :P

[Electronics Man]

Great Job!!!!

[xavec]

This is just outstanding. Top marks for thinking - as wiggins said below - hilariously big. I'm a total sucker for Epic Scale Silliness combined with good craftsmanship, so this sir, is a WIN XD

[wiggins8472]

Hilarious. Well done.

[triumphman]

Dude, that's a lot of compasses! You'll never get lost!

[mpino]

Fantastic! We're going to make one the nature center where I work, to help teach kids about the earth's poles, and orienteering, etc. Also, it's just a great toy for kids to play with!

[mpino]

aaaaand: we did!

[The Porsche Fan]

Nice table! Looks good.
After calculating the cost of the compasses, I can totally see why you arranged them that way

[Wicken]

That is FABULOUS! Great use of the 'Ible.

[Skylberg]

I agree with Muller....Want, want, want, want!

[jimopertrat]

mate that is totally AWSOME!!!!

[simi-kilr]

Nice project. Where can you find cheap glass?

[nerys]

Ok thats just plain cool. I am going to have to do one of these one day.

as for sources of compasses? go a little nuts and even smaller compasses

http://www.dealextreme.com/details.dx/sku.4519

$2.54 shipped for 20 of them. figure what? 1500 of them for this project? $190

would also be cool to use different compasses IE one in the center much larger or spaces around to form a nice pattern

here are some of the cooler ones I found.

http://www.dealextreme.com/details.dx/sku.35475
http://www.dealextreme.com/details.dx/sku.11880
http://www.dealextreme.com/details.dx/sku.11896 (this one is big 6.3")
http://www.dealextreme.com/details.dx/sku.2834

More expensive but much larger and "nicer" for a larger version of this table?
http://www.rinovelty.com/index.cfm/fuseaction/products.detail/item/AMCOMPA/18pc_bulk_compass_set

18 of them for $26 just rip the compass itself out.

These are one of my favorites more money ($1 a pop but also much larger at 2")
http://cgi.ebay.com/60X-New-Plastic-Compass-Key-Rings-Wholesale-/380302127478?pt=LH_DefaultDomain_15&hash=item588bc5f176

best deal (same ones used here)

http://cgi.ebay.com/Wholesale-Lot-20mm-Small-Mini-Compasses-4-survival-kit-/130461497769?pt=LH_DefaultDomain_0&hash=item1e601c79a9

48 for $15 so 500 would cost about $165 you might be able to wheel and deal a better price ordering that many though.

[feistydonut]

144 for $8  on Oriental Trading

[saronpaz]

you might find your project in a bit wider perspective in dunne & rabys placebo project from 2001 which includes amongst others a compass table.

[Jakeg]

I would love to do this project... But unfortunately I dont have the time (or patience) to do it... =(

[Darwinfish]

That's really cool. Just when I thought I couldn't get any more lost... XD

[Bitkid]

So all together how much total money was used to make this project?

[Exocetid]

Not what i thought it was, but still clever! Being old and feeble, I thought it was a table where the top was a compass and pointed North via the coasters. Not as much fun as Noah's table, but just one compass instead of a gazillion--that is how many compasses are needed for this, isn't it?

[woodstockbirdy]

how much did all those cumpases cost???

[Ssslouter]

do the math 1 for 20c, he need 500, 500x0.2 or 1/5 of 500 is 100. it cost somewhere around 100 bucks.

[woodstockbirdy]

ouch thats really expensiv for a table

[mimekiller17]

 lol awesome video, i bet he ALWAYS knows were hes going :) awesome                      North East South West = Never Eat Soggy Waffles, but thanks to ur post, i can eat soggy waffles and STILL KNOW WHERE IM GOING!!! isnt that AWESOME?!?!!?

[kfr1sby]

North, East, South, West
Never eat shredded wheat.
Our teacher taught us that in school, and I still use it to this day lol.

[Quest for Questions]

NEWS stands for north, east, west, south .

[teamcoltra]

Never Eat Sour Worms

[bmlbytes]

Our teacher taught us Never Eat Slimy Worms

[fkuk]

how did you mesure the table to that when you put in the magnets they lined up perfectly with out leaving gaps

[bmlbytes]

You could just measure the diameter of one compass, and make sure the table has a multiple of that diameter.

[xojess]

Oriental trading company sells those little compasses for $7.95 for 144! http://www.orientaltrading.com/ui/browse/processRequest.do?demandPrefix=12&sku=39/37&mode=Searching&erec=2&D=compasses&Ntt=compasses&Ntk=all&Dx=mode%2bmatchallpartial&Ntx=mode%2bmatchallpartial&N=0&requestURI=processProductsCatalog&sd=Mini+Compasses

[CamWaite]

 i vote you mount large magnets in the coasters!

[Derin]

Now make the whole table a single big compass. LOL Good work.

[noahw]

That would be pretty sweet. 

I wonder what the limiting factor is on a giant compass. 

The friction on the rotation point, the strength of the earth's magnetic pull, the weight of the needle itself? 

Anyone have any experience with very large scale compasses?

[Kiteman]

The big limiter is friction - even the compasses you used are balanced on a pin-point (if the table ever gets a big whack, some will come off their pins - be careful).

You could try the ancient floating-needle trick - make a huge compass rose on a sheet of light foam, float it on a pool under a sheet of glass.

At the N & S points of the rose, inset magnets arranged to act as the ends of a bar-magnet.

What would be the point, though?  Once you place the table, it will turn, settle, and never move again.

Instead, I would randomly set neodymium magnets into the sheet of foam, with randomly-facing poles (you can get cubic magnets), so that the foam disc with twitch and turn as magnetic objects are placed on the surface.

[curtismartz]

 the foam would be drawn to one side of the pool and not rotate, ok last comment here. I made a few little mistakes in the descriptions of the huge compasses i have made, the best giant compasses I have made used rare earth disc magnets aligned along the north south axis, they were balanced and hung by a filament, the simplest of which consisted of a single 2" diameter 1" thick neodymium iron boron disk attached to a fine thread with electrical tape and hung from the ceiling, I have used smaller safer : ) disks stuck in the ends of a length of rigid tubing and suspended similarly, various configurations and materials all definitely did some strange things besides aligning themselves north/ south, the strongest were perturbed by passing cars and most of the others responded in unison even when separated a great distance e.g. 40 feet or more, to periodic oscillations that, I have no concrete explanation for but, I think may have something to do with the field produced by the electrical system in the house .  

[curtismartz]

(removed by author or community request)

[Kiteman]

The compasses being used are not "outdoors" compasses, they are plotting compasses, used in schools to show the magnetic fields around bar magnets and similar.  We go through loads every year as pupils drop them and the needles come off the pins.

As for your idea, spreading the magnets out like that will diffuse the poles of the overall field - you'd be much better off lining them all up across the diameter of the disc, all pointing the same way.

[curtismartz]

I think you are right about the pole diffusion, and it would work better to line them up on an axis.  The compasses in this project have no needles. The needles falling off problem sounds like a brand or style specific design flaw that would be super simple to correct, I can't imagine all "impulse" compasses  have this problem, and I don't see anything mentioned in this project that says these aren't outdoors compasses. they look to me very much like a small compass that would be embedded in some type of outdoorsy kind of product. Have you ever seen a survival knife with a little compass in it, or a little key-fob etc. ? This is the same style. anyway.