This project combines two of my favourite things. Magnetic levitation, and puzzles!
Follow the instructions below, and you'll have a fun little conversation piece you can share with your friends.
For this instructable, I'm going to describe how to build a 7x7 maze made of 1/16" magnets, and using a 3/16" disc to float around in it. You should be able to scale up/down the design to whatever size you want.
I should warn you right off that this can be an extremely tedious process. The arrangement you'll be putting the magnets in is inherently unstable and its very easy to accidentally twist a magnet wrong, and half a whole chain reaction that ends with you having to start over!
I just launched a kickstarter project for this, and someone suggested I put together an instructables on how to do it. You're welcome to buy the pieces elsewhere (I've given links to sites I've found that contain many of the parts) or you can buy the whole kit on my kickstarter project.
Step 1: Parts
For a 7x7 square (3 inch x 3 inch) maze, you'll need:
- six laser cut 1/8" MDF parts
- one laser cut 1/16" acrylic part
- one laser cut 1/16" low carbon steel plate
- floor: 1006 nickel plated 1/16" x 1/16" x 1/8" NIB bar magnets (K & J Magnetics has them)
- walls: 284 nickel plated 1/16" x 1/16" x 3/16" NIB bar magnets (K & J Magnetics doesn't have them, but they have 1/16" x 1/16" x 1/4", so you'd have to adjust the laser cut MDF parts slightly to accommodate the extra 1/16".)
- 6 gold plated 1/16" x 1/16" x 1/8" NIB bar magnets (You might have to get some gold leaf and color the nickel plated ones, as I haven't been able to find a retail place that has them.)
- A 3/16" diameter thin piece of pyrolytic graphite. (K & J Magnetics has some square pieces. You'll have to carefully trim around it to get it circular.)
If you're super brave or have incredibly nimble fingers, you might want to try the 1/16" x 1/16" x 1/16" magnets for the floor, and the 1/16" x 1/16" x 1/8" magnets for the walls. To say I'd be impressed if you accomplished this would be an understatement, since you can't eyeball it to see if the magnets are in the correct orientation.
If you're using larger, more easily found but more expensive magnets, simply scale the laser cut parts up when assembling. Keep in mind that price per magnet goes up with the size, and when I last checked, the above magnets cost over $125.
Step 2: Laser Cut Your Parts
Use the included SVG files to laser cut your 1/8" MDF, 1/16" clear acrylic, and 1/16" low carbon steel plates. It shouldn't be hard to find a place near you that will do this for you if you don't have your own laser cutter.
Step 3: Decide on a Maze
Before you start putting the magnets together, its a good idea to decide on your final maze pattern. If you'd like to try some out before you put them together, you can install the Magnet Maze simulation app for Android or iOS and try out a few. The behaviour isn't identical, but it gives you a good idea. If you find one you like, take a screenshot and use that as a reference. I've included one above as well.
Step 4: Putting the Magnets Together
This is the (VERY!) tricky part. There's probably easier ways to do this, but here's the simplest to explain. Its important to do this on some kind of rigid material that you can easily move around for the next step.
The magnets usually come in blocks. Pull off a column of 4 of them attached the long way. (That's really the only way you'll be easily able to pull them off.) If you try to force them another way, you'll most likely end in a mess of magnets that will take a lot of time to get back into a nice even block shape.
Now, very carefully grab four magnets at the one end, and bend them over onto the next four magnets. They will resist until they're pretty much completely bent over. Do this three times, and then very careful pinch the next four magnets so that they detach. This is one internal block of your maze. Pretty easy so far eh?
Repeat that 47 times. When you're done, you have the basic floor of the maze. You have two pieces missing, the start, and the finish.
The start is simply 2 golden blocks next to each other in the center of a 4x4 square, To get this, take two of the golden magnets, and attach them to the two center magnets on one of your 4 magnet columns. Push those two into the column until they're even with the silver ones. At the other end of the column, grab the two magnets that were just pushed out, and place them over the two gold, and push them in again. Now you can do exactly what you did for the regular 4x4 blocks, and you'll end up with a 4x4 block with the 2 gold pieces in the correct place.
Repeat this with the 4x4 golden blocks that we'll use for the end marker.
Now that you have all 49 floor pieces, you can start putting the joints together. First you need the floor joints and the wall joints magnets formed into chains to make it easier to add. I try to limit myself to 8 or so just so that I don't have long ends whipping around that might accidentally hit the maze in progress and wreck it. To do this, instead of folding the magnets together, you pull off four at a time, and join them together in a chain. You'll have to pinch hard on both sides as they're quite strong.
Assembly time! Start by orienting the start position piece correctly, since all the rest can be turned around without a problem. On each side, carefuly place either a floor connector or a wall connector depending on how your maze is laid out. Keep in mind that you have a 50-50 chance of getting the first magnet oriented correctly. If you ever need to remove any magnets, BE VERY CAREFUL! Pulling it away could pull the next completed magnets away, and so on until you're left with a mess. Always firmly hold down the joint where you're removing magnets so that they have less chance of getting pulled away with the magnets you're meaning to pull away.
I usually do the outer wall last, since its one long continous section of the longer magnets.
I've included a video of myself assembling a small 2x2 maze that shows all the above steps in case something is unclear.
Congratulations! You've done the hardest part! (Assuming you didn't throw a big mess of magnets against the wall by now.) You can put the little disc in and very carefully move it around by pushing the maze gently side to side. I would not recommend trying to lift it/move it too much yet, as its likely to collapse and drive you into a rage.
Step 5: Making It Playable
This part is difficult to describe, so I put it into an interactive display.
There are four shorter pieces, two of which have narrower ends then the other two. Its important to pair one of each together properly. The narrower ended piece with a single long narrow gap and three small gaps is paired with the wider piece with two long narrow gaps. When you hold them together, you'll see that two of the long narrow gaps line up. This will be one side of the maze holder. The other side will have a narrow piece with just 3 small gaps, and pair up with the wider piece with one long narrow gap. If you hold them together, you'll be able to see the 3 small gaps through the long narrow gap. Each pair of these goes at each end of the maze, with the three small gaps on the outside, and near the top.
The adjacent maze sides are the last two longer MDF pieces, each of which have barbell shaped openings. These should be oriented so that the long narrow gap is at the bottom. Slide both paired ends into the slots in the dumbbell shapes. When all four are in, you should be able to push them out 1/8" of an inch.
When you've done this with both, there will be room at the bottom of the dumbbell shapes to slide in the 1/16" steel plate. Do that now.
On one of the double MDF sides, you'll see a long narrow slot. Insert the longer clear acrylic so that the end with the small hole stays outside the maze. It should completely cover the metal.
Until the maze is fully assembled, always hold the maze with fingers on each side, as the metal and the acrylic are still quite loose.
Now, very carefully turn the holder upside down, and gently and slowly lower it over the maze until it rests on the flat surface you assembled the maze on. It will be a tight fit, so you may have to gently run your finger along the edge to make sure none of the wall is pushing out.
Holding the holder with one hand, carefully flip the flat surface over, being careful to keep the holder in contact with it until its completely flipped over.
Take the flat surface off, and you should see the maze, still all in one piece, sitting on top of the acrylic. If you only see a flat surface, gently push down with your finger over the whole maze to push the floors down until it all looks correct.
Almost safe! Remember that table cloth trick where all the dishes stayed in one spot while you quickly pull the tablecloth out? That's what we're going to do with the clear acrylic the maze is resting on. Once the maze touches the metal, its going to be VERY difficult to move either the metal or the magnets, so make sure the metal is perfectly centered underneath, and YANK out the clear acrylic. The magnets should drop within milliseconds of each other and leave you with your maze!
Push down gently throughout the maze to make sure everything securely in place, and then drop in the little round piece of pyrolytic graphite.
Finally lets put the clear acrylic top on. Make sure the pyrolytic graphite piece is in the maze before you do this! The top is a bit wider then the holder, but if you let one end fall into the holder, and push gently on that side, it'll slide into the groove and cover the whole maze. It'll still slide back and forth, and probably fall out if you'd turn it upside down, so push the top to one side, and slide two magnets in to the tiny holes on the opposite side. Push the top back to the other side, and repeat. The magnets inside will stay, since together they're longer then the tiny holes, and their attraction will try to keep them straight. If you ever need to get the top off, stick a pin in the side and pull those magnets out.
Step 6: Solve!
Now you're ready to solve it and challenge your friends!
If you decide to make bigger or different shaped mazes with this technique, please let me know!