In an attempt to regain a certain “spring to my step” which seems to have dissipated with my battling of injuries over the last few years, I decided to get back to some bounding and jumping drills. As part of this little experiment I thought it might be nice to get some plyometric boxes. These can be rather expensive though, and being somewhat of a cheap bastard when it comes to things like this, I decided to build some. I am by no means an expert with tools but I have managed to build a few things over the years and I figured with the assistance of a friend who is an expert with tools involving wood, this shouldn’t take too long nor cost too much.
I decided to build three boxes of 4″, 8″, and 16″ height and 2′x2′ square. By stacking them I could get 4″ increments from 4″ to 28″. To keep them from separating I figured I could latch them together. 3/4″ plywood is plenty strong, especially when glued and screwed together, so that would be the body material. It turns out this takes a little more than one 4′x8′ sheet of plywood but I had an old treadmill deck sitting in the basement which would make up the shortfall (3/4″ MDF). So it was off to the lumber yard. The sheet was about $40 plus another $8 for a box of wood screws. From there we went to my buddy’s shop and spent a few hours cutting, drilling, and assembling the units.
Fortunately, I had some left over exterior grade poly, so the boxes got two coats. Now I needed something to prevent slippage. I ordered something called “gymnastic rubber” from an online place but it turned out to be very flimsy. Even at 1/4″ thickness it could easily be torn with just your fingers. I returned it and wound up with a couple of 2′x6′ yoga mats ($9 each, on sale due to discontinued colors-oh the horror). The “gymnastic rubber” weighed a mere 1.3 ounces per square foot. The yoga mats are over 1/4 pound per square foot and should hold up nicely. These were cut into 2′x2′ squares and glued onto the top and bottom surfaces of each box. I had some acoustical sealant laying around which is like caulk that never fully dries, it stays rubbery, so I used that.
Then the latches. It seems you can’t buy decent latches at the local home improvement store. The ones I finally grabbed are made by GateHouse and came with perhaps the cheapest screws I have ever seen. The phillips head slot will strip out with only modest torque. I replaced them with some beefier units I had (3/4″ #8 as I recall).
OK, so the whole thing was less than $100 (not counting supplies on hand) and in total took the better part of a day. The set weighs over 80 pounds. Here’s a pic:
We’ll see if they work.