How to Make the Centrifugal Equation Box (That We Made for Mr. Puzzle!)

First off we want to give a big shoutout to the YouTuber: Mr. Puzzle for solving our Gravitron Puzzle over on his YouTube Channel. (Even though at the time of writing this he hasn't published it yet. We'll have the link HERE once he posts it.) This puzzle is a weird combination of both an impact activated magnet lock and a centrifugal mechanism. It took us many hours and do-overs to finish this puzzle box but not only was it enjoyable, but we learned a lot in the process as well.

Disclaimer: This post contains affiliate links.

• 1 Sheet of 3/8"x7"x5' long Plywood
• 1-1"x 7" Dowel
• 1- 1/2"x7" Dowel
• 1 -3/8"X7" Dowel
• 4- 1" Screws
• 3/4" bradnails

• Woodburning Kit: https://amzn.to/2LYCJfm

• Rare-Earth Magnets: https://amzn.to/2ClVKUX

• Wood Glue: https://amzn.to/2SJXzSj

• Table Saw: https://amzn.to/2SLSLfc

• Combination Square: https://amzn.to/2VFLgbJ

• Chop Saw: https://amzn.to/2Ca5xNE

• Nailer: https://amzn.to/2H4ZcJb

• Drill: https://amzn.to/2LZgxlz

• Dremel: https://amzn.to/2SLfxnH

• Bandsaw: https://amzn.to/2LYI7z6

• Belt Sander: https://amzn.to/2SQUdNH

• Tape Measure: https://amzn.to/2tZ8fBH

• As of right now, I use PowerDirector 16 to edit my videos. It's not the fanciest piece of software but it is great if you're on a budget: https://amzn.to/2Rlwbxm

• Dremel Burrs: https://amzn.to/2XIR0m1

• Bible (not an affiliate link): https://amzn.to/2XIR0m1

To keep things as simple as possible, we made this puzzle into a square that was 6" long on each side. This just made it easier for when we were cutting all of our pieces out.

This was probably the easy part of this project, but all we simply did was cut out our side pieces into 6" squares and then glued/nailed them together. One thing that will make your job easier though is leaving off one side of your box for drawer construction and the top of your box so that you can work on the internal locking mechanisms later on.

The bottom of your box will also need to receive a 1" hole that is halfway through the surface of the wood. The placement of this hole is best done after you have the hole in your drawer done so that you can line both of these up perfectly.

The whole goal of this puzzle is to access this small little drawer. But since this isn't any ordinary box this drawer has a couple of features that help it become apart of the puzzle. While the first 3 sides of your drawer that are hidden inside the box can be attached in the normal fashion, the side piece that you left off should be split in half so that one half can be used as your drawer face. The bottom of your drawer is also a little bit special as well.

The way that we decided to keep this drawer locked in place was by having the bottom of the drawer extend about 3" past the end of our drawer. This extension then received a 1" hole in the middle of it so that we could insert our 1" dowel to lock the drawer. Underneath the drawer, however, we used a Dremel to carve out a small semi-circular area for a latch that we will be making in our next step so that our 1" dowel has to be rotated to be removed.

None of your sequential dowels in this puzzle need to be cut exactly to size right out of the gate, including your largest 1" dowel. The only thing that you will need to do is mark out an area for a 1/4" dowel at the bottom of the peg that is in line with the recess that you carved with your Dremel. Then drill a hole halfway through your larger dowel so that you can glue your smaller peg in place. This small extension of your dowel will act as a latch and help prevent its removal by forcing the user to give the peg a quarter turn before opening the box.

For these next two mechanisms of the build, I would highly recommend watching our Part 1 and 2 videos as they do a much better job of explaining how to create these pieces because they are fairly complicated to explain. Also........ I have a gazillion pictures up above this thing!

In summary, though, the way this first lock works is essentially the same as our Centrifugal Dice Set. Inside the box attached to the wall is a cube made out of Oak (this is important as we learned the hard way that wooden locking mechanisms that are made out of softwoods tend to wear down and warp over time). Through the middle of this cube is a 1/2" dowel that connects to your 1" dowel. Coming in from the top and splitting your 1/2" dowel in half is a hole with two separate rods inside. These rods keep the dowel locked so that the only way to remove the peg is by spinning the box so that the rods are in a horizontal plane. But before you can even think about removing that peg...........

First of all, let me say that I completely understand that the word Gravitron usually refers to the spinning gravity ride at amusement parks. The only reason I used it in my title was because it just sounded EPIC!

Now that that's out of the way, this lock has generally the same setup as the centrifugal peg except for the way in which you unlock it. Basically, the peg that sits inside the wooden lock has a hole drilled into it from above. This hole then receives a small recess that is about an 1/8" in diameter so that you can glue a rare earth magnet of the same size directly onto the peg. Above this magnet is a hole that contains a smooth metal bolt that is connected to a wooden cap embedded with another magnet. So after you attach this mechanism to the wall across from your centrifugal peg, the only way to unlock this peg is to turn the box upside down and bang it on a table or hard surface. When enough force is applied to the box when it is upside down, the metal bolt will jump from the magnet in the peg, to the magnet hanging above it, completely suspending it above the peg and releasing it from its resting place.

Whenever you're making any sort of puzzle box, trimming out your piece is almost essential as it's one of the easiest ways to hide any seams or cracks in your project. Here in this build, our trim pieces not only helped us hide our drawer, but also our pegs. All we had to do was drill out a small space for each of our dowels in the trim pieces, and then glue/nail them down.

Anyone who's watched our videos knows that we love to wood-burn our projects. So for this puzzle box, we covered up all of the smaller seams of the trim pieces and then put some designs all over the box that correspond to the compass on the top. Since we thought that this puzzle would be too hard to solve without any inside knowledge of the box, we added an equation on the bottom of the box to help guide Mr. Puzzle to the solution. If any of you can figure out what all of the signs mean on the bottom let us know down in the comment section.

To seal our project, all we did was apply a very light coat of clear spray-on enamel.

At the time of us writing this, Mr. Puzzle has not received our box yet and has not gotten a chance to open it. Hopefully he'll be able to crack it and then we can show the video to you all!

The inspiration for this project came from our Centripetal Dice Set Video and the Impossible Dovetail Puzzle.