A pink adapted chair sits in a classroom.
Guide

How to make an adapted chair

Step by step directions on how to build an adapted chair, from the Perkins Assisitve Device Center.

General Advice

There are many ways of going about making a seat. You can use all separate pieces, or you can bend larger pieces to curve many of its features. There is a lot of room for individual preference and creative design, but here are a few general principles.

  1. Remember that the cardboard support pieces are stronger when the flutes run up and down.
    flutes written on the side of an adaptive chair seat
  2. Make sure that there are support pieces under any surfaces what will bear weight. If the seat is large there should be center supports as well as side supports.
    side view of a seat showing 3 support flutes
  3. Use a liberal amount of hot glue. Work quickly with this glue. Use clamps or prolonged pressure to make sure that the bonds are secure.

Contents:


Child Measurement

Please follow these directions to learn how to measure your child for an adapted chair.

Once you have the child’s measurements and a chair plan you will begin building the chair by constructing the seat box. Even if the chair will eventually tip back or have a corner style back, we begin with the basic box.


The Basic Seat Box

The seat box is constructed of 4 pieces of cardboard. In all cardboard construction, you must plan ahead to figure out how the pieces will fit together.

1. Determine the size of each piece of the box by using the measurements for the completed seat and accounting for the thickness of your cardboard. Back and side pieces will be shorter than the measurement for the seat height to allow for the thickness of your material.

2. Meaure the pieces and cut them making sure that you take into account the directions of the flutes (or grain) in the material.
pieces cut out and labeled

3. Push a blunt tool (like the back of a spoon) along a ruler to make an indentation across the top/front piece where you want the bed to be. Turn this cardboard piece over and line up the bend just off the edge of the table.
pictures showing the scoring and bending of the cardboard

4. Place the side and back pieces in their proper position on the bent top/front piece. Mark the excess on the ends of the top/front piece and trim. Recheck for fit.
pieces put together and being checked for fit

5. Hot glue the pieces together (make sure you place glue at all points where two pieces of cardboard meet one another). Use clamps to make sure that the part that is bent does not open and glue has time to set.
pieces glued and held together with a clamp

6. Sand box to ensure it is even on all sides.


Modifications to the Seat Box

Cornerback Style Chair (Provides additional support to child’s body):

1. Determine how wide you would like the center panel of the chair to be (typcially smaller than the child’s trunk width).
drawn sketch showing corners marked

2. Using that measurement, mark where the back corners of the chair will be, on the top/back of the seat. Meaure, along the back of the seat, from your mark to each corner (these marks should be the same distance.)

3. Mark this same distance down the side of the chair top (this will ensure that you will have 45 degree angles at the bends). Draw the diagonal line across between these points.

hands measuring the corner of seat

4. Extend this line down the sides of the box as well.
measuring the diagonal line between two points

5. Saw off the back corners of the box with a hand saw (or a band saw if the seat is low enough to fit).
sawing off the corners

6. Fill in the back corners with small pieces of cardboard to add stability to the seat.
pieces filling in the back corners


Chair That Tips Back in Space

Supports children with low muscle tone or who are unable to hold themselves upright against gravity, while maintaining their hips, legs and feet in proper position. Also known as a Tilt in Space Chair.

Chair with a Back That Reclines

Opens the angle of the hips past 90 degrees.

  1. Determine how far back you would like the chair to recline.
  2. Mark the angle of recline on the back of the seat box and cut. (In this case you could have just eliminated the back piece and cut the side pieces to the correct angle before gluing.)


Wrap Around for Back and Sides

  1. You accomplish this by cutting parallel lines along a straight edge with a box cutter and removing the first layer of corrugation between these lines.
    Then fold along these troughs.
    exacto knife cutting parallel lines
  2. The size of your grooves is determined by what angle you are looking to achieve. For a 45 degree angle your groove will be smaller than if you were looking to make a 90 degree angle. (For our 5/8” thick material we allow 3/8” for 45 degree bends and 3/4” for ninety degree bends.)
    insides folds

 Creating the Wraparound Piece for Back and Sides

Draw out the following shape if you are making a chair with a basic square back.
illustrating of back piece

Draw the following shape if you are making a chair with a corner-style back.
corner style back illustration


How to Construct and Attach Back/Side Piece

  1. Draw the shape of your wrap around piece on a large piece of cardboard, using the rules listed above.
    back and side piece of a chair
  2. Cut out this back/sides shape.
  3. Score the lines where the folds will be and pull out the top layer of corrugation between the scored lines.
  4. Use needle nosed pliers, a chisel, or a screw driver to remove this material.
    chisel removing cardboard strip
  5. Bend this piece and fit it to the box.
  6. There may be a bit of excess in the front.  Mark and trim this.
    pencil marking trim areas on cardboard
  7. Mark a line around the seat.  This will remind you not to put glue above this line when assembling.
  8. First apply glue to the center panel of the back piece (be sure to stay under the line).
    gluing under mark line
  9. Once the center panel is glued, apply glue to one side and clamp.
    back and one side glued and clamped
  10. Once that glue is set apply glue to the final side. Squeeze the wrap around piece tightly around the box, ensuring a snug fit.
  11. Put large clamps across the front of the seat for a few minutes to make sure that the bent piece won’t open making a weak joint in the front.
    chair all glued with clamps

Modifications for Tilt-In Space Chairs

  1. Draw the shape of your wrap around piece, using the rules listed above for a corner style.
  2. Use a large piece of cardboard with a straight edge along the bottom.
  3. Ensure the flutes are running up and down.
  4. Draw a straight line (from the bottom up) where you will begin your measurements. It should be as long as A+E (minus 5/8 or the thickness of your cardboard).
    cardboard sketched out
  5. Measure the first side of your box (1), using that measurement (plus adding 1/2 inch) mark where the next line will be and draw your next line on your large piece of cardboard.
    seat box with numbered sides
  6. Next you will make a groove for your first 45 degree bend. Measure 3/8 inch from your last line and then mark your next line. This line will be the length of A+D.
  7. Measure area (2) of the seat. Then mark that distance and draw your next line to the length of A+D.
  8. Measure 3/8 inch for your second bend and draw your line to the length of A+D.
  9. Continue this process until you have made it around the back/sides of the seat box (ending with the measurement for side (5) + 1/2 inch
    NOTE:  When making a tipped back chair you have the option of having the armrest be parallel with the seat or modifyng your drawing further (same as picture above) to have your armrests parallel with the floor.
  10. To make the armrests parallel with the seat, the height of the front and back of the armrest should be A + E (minus 5/8 inch or the thickness of the cardboard).
  11. To make the armrest parallel with the floor you will have to add the same amount of tip for your chair to the armrest.
  12. Use a protractor to find your angle and then draw a line along that angle from the front tip of the armrest to the beginning of the back of the chair.
  13. Be sure to extend your 3/8 inch groove to account for this change.
    10 degree angle for armrest
  14. Cut out the wrap around piece.
  15. Score the lines where the folds will be and pull out the top layer of corrugation between the scored line. Use needle nosed pliers, a chisel, or a screw driver to remove this material.
  16. Bend this piece and fit it to the box. There may be a bit of excess in the front. Mark and trim this.
  17. Draw a line on the wrap around piece which indicates the location of the top of the seat.
  18. Glue the seat box to the wrap around piece starting in the center and moving out to the sides. Clamp the two pieces together and allow time to set.

How to Cut the Chair to Allow it to Tip in Space

  1. Cut a cardboard piece with one edge that matches the angle of tilt that you would like your chair to have. Example: We want to tip our chair back 10 degrees (from 90 degrees) so we a cut a piece of cardboard that has an 80 degree angle.
    80 degree angle on cardboard
  2. Put this piece right up against the back of your seat. Measure how high the front of the seat lifts up off the work surface.
    measuring seat lift
  3. Use that measurement to mark the distance, on the center panel of the back of the chair, from the bottom of the seat up and draw a line across center panel at this height.
  4. Measure the degree of tilt that you want from the bottom front corners of the seat along the sides. Mark these lines.
    measuring degree of tilt
  5. Connect ends of the side and back lines.
    connecting ends of side and back lines
  6. Cut along this bottom shape with a hand saw, jig saw, or a serrated knife.
    cutting with a handsaw and a jig saw
  7. Sand as necessary to make sure that the chair sits flat on the floor.

sanding and ensuring that the chair sits flat


Arm Rests

Arm Rest Supports


Strap Slots

You can cut the slots for straps with a serrated knife or an oscillating tool. We usually make our straps 2 inches wide, so the slots work well when they are 2 inches loong by 1/2 inch wide. The following are some guidelines for placement of these slots.
cutting out the strap slots

Slots for Shoulder Straps

Slots for the Chest Strap

Slots for Pelvic Belt

Slots for Headrests (not pictured)

Slots for Foot Straps (not pictured)


The Base

  1. Measure and cut the base using the rules outlined above.
  2. Round all of the corners.
  3. For a square chair center the chair on the front of the base. Outline the base of the chair where the border for the glue is and glue the base into place.
    square chair on base
  4. For a tipped back chair leave the necesary space for the foot and center the chair. Outline the base of the chair where the border for the glue is and glue the base into place.
    tipped back chair base

Footrest

  1. Measure and cut a piece of cardboard for the top of the footrest by taking the length of the child’s foot plus 2 inches and the width of the chair.
  2. Make angled support pieces that match the angle of tip for the chair.
  3. Add a support piece to the front of the angle pieces and glue together.
    footrest with front support piece
  4. Sand the back of the foot rest to match the angle of the front of the chair.

Inset for Pummel

Detailed directions for how to create the pummel are included on the Building Guides page.

  1. Cut a 3/4 inch diameter hole in the center of the seat as close to the front as possible.
  2. Cut a piece of 3/4 inch CPVC the same height as the seat of the chair.
  3. Dribble hot glue through the hole onto the base and put some more around the inside of the opening.
  4. Slide the pipe into place.
    pipe flush to chair bottom

The Back Support or “Fin”


How to build an Adapted Chair on pinterest - Make your own custom adapted chair using these few basic principles