DIY Home Gym – Crossfit plyometric boxes

Standard

The plain old box is a versatile tool in your home gym. You can use it for box jumps, but it can also be used for weighted step ups, reverse rows and a multitude of other movements. I initially looked on the Rogue Fitness website to buy two boxes, but at $125 a pop for a flat pack box which still require assembly (plus tax + shipping), this definitely seemed like something I could make myself at home to save a few dollars.

 

diy home gym crossfit plyo boxes

diy home gym crossfit plyo boxes

Require Tools + Materials

  • Saw
  • Ruler
  • Pencil
  • Wood Screws 1 1/2″
  • Power Drill
  • Drill bit
  • Screwdriver
  • Countersink drill bit
  • Plywood, 2x 4’x8′ board, 1/2″ or 3/4″ thickness
  • 2×4 pieces 3×30″ roughly
  • Safety Goggles
  • Clamps
  • Sandpaper (or electric sander)

Total Cost: 4’x8′ plywood sheet ($40) + screws ($7) + 2×4 ($4) = $51

diy box equipment

diy box equipment

3-in-1 box design

The design I build was the same as the Crossfit Games box, it has sides with dimensions 30″, 24″ and 20″ the great thing about this is that you get three boxes in one, just change flip the box over and you can alternate between different heights, this is great if you don’t have much space to store multiple boxes.

Here is a cutout for the 30″x24″x20″ box, as you would cut on a 4’x8′ plywood sheet (in my case I added the cuts I asked home depot to make to split the board into 3 pieces)

IMPORTANT: The dimensions I show below assume the plywood is 1/2″ thick, if you are using 3/4″ plywood then you will need to adjust them accordingly

Cutout for DIY Crossfit Plyo Box

Cutout for DIY Crossfit Plyo Box

Step 1: Cut the sides of the box

I bought two 4’x8′ 1/2″ plywood boards from Home Depot, if you are like me and don’t own a big truck then you may have issues fitting those boards into your car. Luckily Home Depot (and other stores I suspect) will cut the wood for you in the store, there is generally a cutting station in the lumber section, ask one of the staff members to see if the store you go to has one.

You may be tempted to get the staff to do all the cuts in your wood, instead of doing it at home, that is an option, but I believe generally they don’t like too many cuts per customer (or they may charge) plus how accurate the cuts are is in doubt, best to let them do some big cuts then do a more accurate cut at home. For me I just asked them to cut each sheet into three 32″x48″ piece, basically three even pieces along the longest edge, all the sides of the box neatly fit into that.

Setup for making long cuts with a circular saw

Setup for making long cuts with a circular saw

Side Note: Should you use 3/4″ or 1/2″ plywood – I chose to use 1/2″ because I wanted the boxes to be a bit lighter when you were moving them around, but just to be sure I added 2×4 internal supports to the box, this is more work, if you use 3/4″ plywood then you probably won’t need to add the internal supports, it’s your call.  I’m very happy with the 1/2″ plywood with the added 2×4 supports (see later) there is no way the box will give way.

Final cut DIY box pieces

Final cut DIY box pieces

Disclaimer: using power tools is dangerous, make sure you understand how to safely operate your tools, don’t have loose hanging clothing and jewelry and always make sure you are wearing safety goggles anytime you are cutting, drilling or screwing.

Step 2: Glue sides and add holding screws

You don’t need to add all the screws at once, I just added screws in the corners quickly to hold the basic structure, then once everything was in place I then added all of the extra screws. Here is a picture:

Starting to join pieces

Starting to join pieces

 

You can see that I have already marked where I will drill all of the screw holes on the surface. I put screws every 3″ (which is total overkill, but hey) and 4/16″ away from the edge which will be right in the middle of the 1/2″ ply edges. Once you have the corner screws in, you will have a basic shape that you can add more permanent screws to.

Basic box coming together

Basic box coming together

 

Step 3: pre-drill and countersink the screw holes

It’s important to pre-drill the holes so that you don’t split the plywood, also you don’t want any screw heads above the surface so I counter sunk all of the holes as well, see below:

Pre-drilled and countersunk holes

Pre-drilled and countersunk holes

Holes with wood screws

Holes with wood screws

Step 4 – Add support braces

Even though the boxes felt super solid, over time I wasn’t sure if continued jumping would potentially weaken the wood, plus the two ends when jumping on the 30″ side are insets so only supported by the screws and glue, so I really wanted to make sure everything was really safe, I didn’t want to be worrying every jump.  So I added some 2×4 supports to each side of the box that I was going to be jumping on, adding the braces made the boxes rock solid. I basically glued and screwed the 2×4 onto the inside of the box, as shown below:

Supports for extra strength

Supports for extra strength

I then added screws down the length of each support on the outside surfaces.

Step 5 – Sanding

The last stage is to sand the edge of the boxes, after cutting the plywood there were some sharp splinters, you want to be able to grab the box on any edge, plus if worst comes to worst and you eat it on a box jump the last thing you want is a bunch of splinters digging into your shins – ouch.  So make sure to thoroughly sand each edge and the corners so they are smooth, plus sand over each screw just to make sure there are no sharp edges around the countersinks.

Rough edges before sanding

Rough edges before sanding

Smooth edges after sanding

Smooth edges after sanding

Step 6 – Jump on them

Now you’ve got a sweet DIY plyo box, you have to jump on it – enjoy!

Standing on Crossfit plyo box

Standing on Crossfit plyo box

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