Saturday, August 29, 2009


We were going to go up to Mores to check out some formations, but my shoulder has been jacked. I may have hurt it climbing last week, which sucks, since the Pocatello Pump is in about 2 weeks! I decided to make a plyobox. I have been doing box jumps on an irrigation box, but it's less than 20" tall and I have to put it up on something to get it to 24" (which is dangerous).

Ski season is coming up fast and I need to get my legs in better condition. A plyobox is a great tool for plyometric jumps and set-ups & weighted step-ups. They are not that hard to build. I used AC plywood, 3/4 inch. CDX is cheaper, but Lowe's had a pretty ragged selection. Lot's of great (more expensive) AC, though. I had Lowe's rip it in half lengthwise. Brought it home and got to doing some layout.

I got the plans off of the Crossfit website. I don't do Crossfit, but there are some pretty skilled equipment craftsman on the forums. I don't know what it would cost to buy a plyobox, but I doubt it's less than $15 (half a sheet of 3/4).

Then I cut out the components.

Next, I cut the ends to a 6 degree angle. I could have made one cut per end, but since only one side of AC is finished, I had to flip the piece over to have matching angles.

All parts done, now it's time for assembly.

All done except for the top. If you make two 24" boxes out of one sheet, you will need to have some scrap 3/4 or you can make one 24" and one 20" and the layout will leave just enough for the tops.

Kaden gave it the first go. He tried to pull off the jump many times. He got to where he would land on his knees. If he could nail the jump onto his feet, that would be the equivalent of me doing about a 50" jump! I have seen guys from Gym Jones hit a 42" jump, but they are at another level.


brian p. harder said...

Hey Ralph,
Thanks for the comment on the site. Unfortunately, the LOTOJA piece got published before it was finished. Feel free to check it out now for the full blow by blow.

Gonna have to make me a box or two. Did not know the plans were on the CF website. Makes it easy.


brian p. harder said...

Got the boxes done. Turned out pretty well. Did a 20" one with a 14" stackable extension. Kinda trick. Found some extra 1/4" rubber gym floor to surface the top deck. Very nice addition. Thanks for the inspiration.

I'll be in your neck of the woods over Christmas. Taking my bad ass 15 and 13 year old nephews up in the Pioneers for a little winter mountaineering schooling. If we get some snow, we are going to climb and ski the North Couloir on Cobb. Can't wait.