Wedge

Wedges have lots of uses. They are great for sitting on, to promote a forward-leaning posture. They are also great as lap desks. And they can work as a footrest for someone that wants angled foot support.

The dimensions in this Instructable are the dimensions I use for my class. The dimensions should be adjusted for the specific person who is going to use it.

I learned to do cardboard carpentry at the Adaptive Design Association

Tools

1. Tape measure
2. T-square
3. Foam brush
4. Box cutter
5. Jigsaw
6. Pen
7. Awl
8. Mallet

Materials

1. Tri-Wall Cardboard
2. White glue
3. Wooden "Nails"
4. Glue tape
5. Water
6. Primer
7. Paint
8. Polyurethane

I like to cut a piece with a lot (6-inches or so) of excess cardboard to give me flexibility when making my folds.

1. Mark out where you want your cardboard to bend
2. Score the cardboard with a box cutter
3. Remove excess cardboard from top and bottom

A note on bending cardboard: Ideally, you will get the entire width of the cardboard to fold along a single "flute" (what I call the "grain") of the cardboard. One way to help this along is to take a box cutter and cut along a single flute.

Remove the excess cardboard to make your wedge as high as you want it to be.

1. Use clamps or tape to hold the folds in place
2. Use the folded main piece to measure out support pieces
3. Cut 3 support pieces

In an ideal world, your wedge will be a right triangle. In the event that you do not live in an ideal world, you may need to deal with the problem of having to cut oddly-shaped support pieces. My preferred method is:

1. Measure out all three sides
2. Cut something (cardboard, straws, wires...) to the length of two of the sides of the triangle
3. Use those lengths to draw out the desired shape on tri-wall cardboard
4. Once you have one support piece that's the right shape, use that as a template to cut out the next two support pieces

1. Use the support pieces to mark out where the nail holes should be
2. Punch holes for nails
3. Use hot glue to attach support pieces to bottom
4. Use hot glue to attach support pieces to top
5. Use hot glue to attach support pieces to back

You may need to use clamps and/or masking tape to hold the wedge in place until the glue dries.

1. Connect bottom and back with nails
2. Connect back pieces to support pieces with nails

It's possible that the top and back of your wedge won't line up exactly right. You can fix this problem by cutting off a strip of cardboard and gluing it in place before you apply edging.

You need to seal off the edges to help keep water out. I use gummed packing tape. You can look at this video from the Adaptive Design AssociationYouTube channel