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CrossFit Journal Article Reprint. First Published in
CrossFit Journal Issue 49 - September 2006
Plyo Box with Slanted Sides
Lincoln Brigham
Plyo boxes are very popular in CrossFit gyms. They’re
great for all kinds of workouts—or for just sitting on
after a good workout with your head cradled in your
hands waiting for the room to stop spinning. However,
commercial plyo boxes can cost as much as $100 to $200
each, plus shipping. Homebuilt equipment—a favorite
CrossFit brand—can be constructed with quality at
least equal to that of the best commercial designs and
at significantly lower cost. Square boxes and open-sided
boxes take a bigger toll on the shins from missed jumps,
and slant-sided boxes are stackable, so they require less
floor space for storage. So this month’s journal brings
you the do-it-yourself CrossFit custom plyo box with
slanted sides. Your friends, relations, workout buddies,
and clients will be sore impressed! Or just plain sore
after a hard workout on one of these babies. Total
cost for this project should be in the neighborhood of
$40-60 per box or less, depending on the size and your
bargain-shopping abilities
Cardboard mock-up
The first step is to use the instructions below to build
a mock-up of the plyo box with the cardboard and
packing tape. Really. Trust me on this. it’s worth the
time. With a cardboard mock-up, these plans can easily
be adapted to any size plyo box desired. Additionally,
building the cardboard mock-up saves a lot of tedious
measurement calculations and head scratching, and it
serves as good practice for measuring and assembly
before cutting into expensive plywood. As carpenters
always say, “Measure twice, cut once.”
of 4
® CrossFit is a registered trademark of
CrossFit
,
Inc.
© 2006 All rights reserved.
Subscription info at
http://store.crossfit.com
Feedback to
feedback@crossfit.com
Plyo Boxes
(continued...)
(left) a cardboard mockup helps make sure the box is the right size for your application. (right) how to make the most of your plywood.
Materials
5 sheets of 24” x 20” cardboard
Packing tape
4’ x 8’ x 3/4” maple, oak, or birch plywood, 1.5
sheets per two large 20” boxes (Skimping
with cheap or thinner plywood is not worth
the savings. And don’t even think about using
particle board.)
18” x 18” rubber mats, one per plyo box
(try the local feed & grain supply store)
1-1/4” drywall screws, 40 per plyo box
Wood glue
Contact cement, 1 pint
Base paint (primer paint for use on wood)
Semi-gloss colored paint
Semi-gloss polyurethane varnish
Bumper sticker from CafePress.com
base and 17.5” square top, but you can scale them to
whatever size boxes you want.
You can also make the angle of the slope as steep as
you like, bearing in mind that assembly and cutting gets
trickier, and stability decreases, as the angle increases.
This project uses approximately a 10-degree slope. If
you are not comfortable with woodworking and cutting
wood at an angle, you can make the box with straight
sides.
Each side of this box will be 23.5” wide at the bottom
and 17.5” at the top. Always remember that the plywood
is 3/4” thick. This means that two of the sides will have
Equipment
24” straight-edge ruler
Table saw or circular saw
Variable-speed drill with screwdriver bit
Jig saw
Utility knife, carpet knife, or box cutters
Sander with both coarse-grit sandpaper and extra-
fine-grit sandpaper
Safety goggles
Instructions
These instructions are specifically for making a pair of
boxes that are approximately 20” high, 23.5” square
2 of 4
® CrossFit is a registered trademark of
CrossFit
,
Inc.
© 2006 All rights reserved.
Subscription info at
http://store.crossfit.com
Feedback to
feedback@crossfit.com
Plyo Boxes
(continued...)
these dimensions and two will be cut 1.5”
narrower: 22” at the base and 16” at the top.
Draw a 3/4” edge on the cardboard mock-
up to get a good visual on this.
Use the cardboard mock-up and the ruler
to lay out the patterns to be cut on the
plywood. The sides for two boxes can be
cut using just one sheet of plywood if the
base of the box is 23.5” or less. Be sure to
leave about 1/4” between cuts to allow for
the width of the saw blade!
Now begin the cutting. The top and bottom
edges will be cut at an angle so that the top
sits flat on the sides and the whole thing sits
flat on the ground. Set the saw blade angle
by eye using the cardboard mock-up as a
visual guide. The angle is not super critical,
just be sure that you cut the top and bottom
edges at angles parallel to each other. If idea
of parallel angles sends you back to horrible
memories of ninth-grade geometry, simply
make sure that you start the long cuts from
the same end of the plywood each time.
Using the layout picture, make the four rip
cuts (i.e., the long way) with the blade set at
an angle. Then set the saw blade back to 90
degrees to finish the rest of the cuts.
Do not try to cheat by using square cuts for
the top and bottom edges. This will result in
a box that is difficult to assemble and finish
as well as significantly weaker. Again, if you
are not comfortable with angled cuts, build
a box with straight sides. You may scrape
more skin off your shins with straight sides,
but at least you won’t tear your hair out trying to screw
the box together, and the box won’t collapse when
Trainee Ted the Tort Attorney jumps on it.
Pre-drill holes for the screws 3/8” from the sides of
the two wider pieces Glue and screw the box together,
using the packing tape or a helpful friend to hold the box
together while you screw down the pieces. Don’t use
nails instead of screws; that’s just asking for trouble.
Be sure to make angle cuts for the
top and bottom edges of the side
pieces to ensure snug, strong corners
when assembled (top left). If you’re
not fully confident in the strength
of the corners, some bracing can
be added (top right). Use screws
to assemble the boxes, not nails
(bottom left).
angle as the sides, pre-drill screw holes at a slight angle
3/8” from all four edges of the top, and glue and screw
the top into place.
If the joints are nice and tight, no further bracing should
be necessary. If you are nervous about your carpentry
skills, additional internal bracing in the corners may be
helpful.
Next, draw outlines of handle holes on two opposite
sides of each box. Drill a starter hole for the jig saw in
the middle of the handle area. Make the hole big enough
for the saw blade. Cut the hole for the handle slowly,
being careful to rein in your great CrossFit strength to
avoid twisting, tilting, or snapping the saw blade.
Glue & screw = strength and durability
Turn the box upside down onto the remaining plywood.
Use the assembled box as a guide for the measurements
for the top. Cut the top so the edges are at the same
of 4
® CrossFit is a registered trademark of
CrossFit
,
Inc.
© 2006 All rights reserved.
Subscription info at
http://store.crossfit.com
Feedback to
feedback@crossfit.com
Plyo Boxes
(continued...)
Sand the edges and joints smooth with coarse sandpaper,
especially the edges of the handle holes. Use wood
putty if necessary to hide any gaps. Paint the sides—but
not the top—of the box with a base coat. (Warning: if
you don’t use a base coat, you’ll need at least 4 coats of
color.) Let dry according to directions on the paint can,
then finish painting with a coat of semi-gloss color of
your choice. After the paint has dried, apply 2-3 coats
of polyurethane with fine sanding in between coats. Do
not paint the top!
Sand the top of the box to remove any stray paint.
(You didn’t paint the top, did you? If you did, sand it off!
Contact cement won’t hold on paint.) Cut the rubber
mat to size with a utility knife. Again, angled cuts that
continue the slope of the sides will look more profes-
sional. Apply one coat of contact cement to the bottom
of the mat and one coat to the top of the box. Let dry
for 15 minutes before assembling. Contact cement is
strong as heck but tricky to work with—you’ll get only
one shot at assembly and then it’s stuck for good, so
align the mat with the box carefully before actually
setting it on. Be sure to let the contact cement dry until
tacky before applying the mat. Use a hammer on the
mat to ensure full contact. If done correctly, the contact
cement will be stronger than the plywood.
If you plan on stacking the boxes, glue a 4” x 4” piece of
leftover rubber mat or plywood to the underside of the
top. This will keep the boxes from sticking together.
For a slick custom look, you can create a custom bumper
sticker online to use as a label for the box. It’s only $3
plus shipping. If the logo has a distinct border, a nice
visual touch would be to carefully cut along the border
with a sharp knife before removing the backing. This will
make the logo look less like a bumper sticker and more
like a custom logo
Down and Dirty
Bombproof Low
Plyo Boxes/Pulling
Blocks
Materials
18 feet of 2” x
10” lumber
(actual board
dimensions 1.5”
x 9-3/4”)
60 long drywall
screws
Wood glue
Equipment
Saw
Screwdriver (variable speed drill would be very
helpful)
Instructions
Cut the lumber into 1- foot lengths. Glue and screw nine
pieces together to form one 12” x 13.5” x 9-1/4” block.
Make two for use as pulling blocks, used to develop and
strengthen the second pull in the Olympic lifts.
Lincoln Brigham is owner of
CrossFit Sedona
.
He is a USA Weightlifting Club Coach,
CrossFit level II trainer, and CSCS (Certified
Strength & Conditioning Specialist) with the
NSCA (National Strength and Conditioning
Association). In addition to medaling at the 2002,
2003, and 2004 National Masters Weightlifting
Championships, he is a dance instructor and
dance competitor and medalist at the 2004 and
2005 United Country Western Dance Council
World Championships. He and his girlfriend
Adrienne Harris (whom he coached to a gold
medal and nine national masters records
at the 2003 National Masters Weightlifting
Championships) are probably the only people in
the country who have competed in and taught
both dance and Olympic weightlifting.
This would be a cool bumper sticker.
4 of 4
® CrossFit is a registered trademark of
CrossFit
,
Inc.
© 2006 All rights reserved.
Subscription info at
http://store.crossfit.com
Feedback to
feedback@crossfit.com
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