A lot of people are interested in making their own plyometrics boxes. While not trivial, with some basic woodworking and DIY skills, this is entirely doable.
The welded steel boxes you buy are probably going to be more durable than any homemade wooden box, but remember that those steel ones are built for gyms. In a commercial gym, dozens of people might the equipment throughout the day, but in a home gym, the equipment just doesn’t take the same amount of punishment. For this sort of personal use, a wooden box is fine, provided you build it well and avoid a few common mistakes. So let’s take a look at how to do that.
This design is for a wooden box with sloping sides. The sloping sides allow for a wider base which makes the box more stable, as well as allowing you to stack the boxes for compact storage.
You will need some plywood, a saw, wood glue, screws, a drill, a non-slip rubber mat, contact cement and some spray paint. You can get all of these in your local hardware store, except for the non-slip mat, for which I’d recommend checking a home fittings store, in the bathroom section.
Step one – Cut the wood
You need to cut five pieces of wood: two big side-pieces (shown in green), two smaller side-pieces (in blue), and the top.
Remember I said there were common mistakes you had to avoid? This is one of them. Some people make the mistake of cutting four sides that are the same size, and end up with a box that doesn’t fit together. It seems obvious at first that because a square has four equal sides, you need to cut four pieces of wood that are the same. But this fails to take into account the thickness of the wood itself. Look at this picture –
This is a perfect square, but the two green sides are longer and fit around the two shorter blue sides. Your box must have two big outer sides that overlap the two smaller inner ones, otherwise it will not fit together.
The two small side-pieces are trapezoids. The height h is the desired height of your plyometrics box. Most commercial brands are between 15cm and 105cm, but feel free to use whatever height you want.
The width at the bottom is 55cm and at the top it is 40cm. This is fine for most mid-range boxes, but very tall or very short ones you might want to alter them slightly. A good rule of thumb is to have the bottom 10-20% wider than the box is high, and the top 10-20% narrower.
The two big side-pieces are the same, except to allow them to overlap the small side-pieces you have to make them twice width by twice the thickness of the wood. Plywood is normally sold in sheets three-quarters of an inch thick, so add 1.5 inches to the numbers you used for the smaller side-pieces.
The top is simple. Just cut out a square whose sides are the same length as the top of the large side-pieces.
Step two – Shave the edges
Now we need to stick these pieces together, but before we do, we need to make them fit. This is the other common mistake people make. If you try to stick the five pieces you just cut together to make a box, it won’t work. To understand why, look at the picture below –
The orange side piece has been cut squarely. When you try and stick this square cut to the top of the box at an angle, it leaves a gap. There is also a gap where it meets the ground. If you tried to screw a piece like this to the top, it wouldn’t be easy. Even if you do get the screws in, your box will fall apart the first time you jump on it.
The pink piece on the right shows how it should be; the ends are cut at an angle. Note that the pink shape is not a rectangle, while the orange shape is. These angled cuts allow the pink shape to fit snugly against the top of the box and against the ground.
So take your four side pieces – both the two small ones and the two big ones – and start shaving the edges with a lathe (if you have one) or with a saw, until they fit snugly against the ground and against the box. You will probably need a friend to hold the pieces in place while you test this.
Step three – Stick the pieces together
When you are satisfied with the cuts of the wood, stick the side-pieces on to the top. Different wood glues have different instructions on the bottle, but you will typically need to put glue on both pieces and press them together for fifteen minutes. Make sure you glue the top to the side-pieces in such a way that the side-pieces are directly underneath the top, firmly supporting it (as in the left picture the below). Unless you’re making this box for practical joke purposes, don’t put the wood glue on the sides of the top-square and attach it that way (as has been done in the picture on the right). Guess where that top square is gonna end up when a big guy jumps on it?
Glue on all four sides and leave to dry. Now, you didn’t think we were gonna rely just some wood glue to hold this together, did you? We want a box that will take a beating and ask for more. You need to add screws as well, and the more the better. Use a power drill to drill downwards from the top square into the sides – five screws on each side is good (probably overkill, but good). Also drill and put screws through the big side-pieces where they overlap the small side-pieces. Again, I recommend five screws on each of these four seams.
Step four – Stick mat on
Congratulations! You’ve built the box, now for some finishing touches.
Plyometrics boxes need a good non-slip surface, especially if you’re gonna be doing anything that involves jumping on and off them at speed. What I recommend you use for this is the rubber non-slip mats they sell for showers. Cut it to fit the top of your box. You can buy these in some home decorations stores, or get one on Amazon here.
Use contact cement to stick this on. Contact cement hardens quickly, so make sure you get it on right first time, with no wrinkles or bubbles.
Step five – Spray paint
That concludes the functional work of making a plyometrics box. Next to pimp it up the way you like it. To me, bare wood like that is calling out to be spray-painted and stencilled. I’ll leave this step to your own creativity.