This fun and unique chess set is designed for people with hand and wrist motor function difficulties. Pieces feature large heads and thick necks for users to hold them comfortably; additional weight pieces allow caretakers and physical therapists to adjust weight to aid in muscle strengthening.

BONUS: The bases may also function as checkers pieces!

Our client is a physical therapist who initially asked for our assistance to make a chess set for a young girl who wants to move on from using her wheelchair to using a walker, but needed some strengthening and practice. In order to assist this initial patient, the PT requested that the pieces have heads that are similar to those of walker handles. There is also potential for this weighted chess set to be used with patients recovering from strokes, so the pieces are enlarged for easy holding by anyone.

Supplies

Materials

PLA filament. This can be any color you want, but we recommend having at least 25 lbs.

Sixty-four squares of a solid base material. We purchased two sets of these wooden squares.

A large piece of foam you can cut. We purchased this yoga mat.

A 24" by 24" picture frame. The space inside should be 24" by 24", the frame should not count towards that length. We purchased this frame.

Two stainless steel 3.5" by 3.5" piano hinges.

Super glue.

Paint (optional)

Clear sealant (optional)

Approximately 50 lbs of lead shot. This can be purchased at many local sports stores in the ammunition department, but it will only be used to add weight.

Plastic hole plugs. However many is determined by how many bases you will be making. We made 96 and purchased these.

Tools

A computer.

A 3D printer

A 3D printing software that works with your 3D printer.

A saw.

A knife or clippers. This will be used to remove the supports on the outside of the pieces and the inside of the bases.

Sandpaper. We used 300 grit for rough sanding and 1000 grit for smoothing.

Step 1: Download Files

Download the files.

You can find the files that we used here. These are the individual pieces and you will need to print multiple copies in order to have a full chess set.

The bases are all the same size but will have indents with the intended weight listed. Feel free to ignore this and set up the weights to your preference instead.

These files are adjusted versions from uppalong on thingiverse. Click here for the chess link.

Step 2: Load and Slice

Load the pieces into your 3D printing software.

This is an example of what it should look like when the plate is sliced. Supports should be included.

Step 3: Printing Pieces

Load the sliced files into the 3D printer and begin printing.

This is an example of what the pawns will look like when printed. Note the supports, these will be removed in the next step but are necessary for proper printing.

Step 4: Processing

Remove the supports.

You can use a knife or clippers to remove the supports. You may have an issue removing the supports inside the base without damaging the thread. If the inner thread of the opening is damaged, use super glue later to hold the plastic screws in place.

This is what the pawns in the previous image look like after processing.

Step 5: Sanding

Sand the pieces where the supports were and along the threads.

While sanding the support zones is optional, sanding the threads at the base of the pieces and the bottom and top of the bases is a good idea. Depending on the printer nozzle, the filament may come out a little lopsided and you may have some difficulty screwing the pieces to the bases.

This is what the pieces look like when sanded.

Step 6: Fill Bases

Fill the bases with lead shot.

Place your processed and sanded base onto a scale and add lead shot until the scale reads the desired weight. It's a good idea to do the filling above a bucket, because the lead shot is very small and can go all over the place if you aren't careful.

This is an example of the set up we used for filling.

Step 7: Plug Holes

Plug the opening of the bases using plastic hole plugs.

Apply a small amount of super glue to the sides of the plug and place the plug into the opening. Ensure the cap is flush with the top

Step 8: Cut Foam

Cut the foam into 3" by 3" squares. Use the wooden squares as a guide. You should end up with 64 squares.

Use your knife to cut the foam into squares. The foam serves as both a cushion to absorb the impact of the weighted pieces on the board and a way to prevent sliding pieces.

Step 9: Cut Photo Frame

Cut the photo frame in half.

Remove the glass cover and use the saw to cut the frame and backing in half.

Glue hinges on the back of the board. Use super glue or gorilla glue to glue the two hinges to the back of the board. Have the closest end of the hinge 3" away from the frame.

Glue the foam squares to the wooden squares.

Glue the squares onto the two halves of the photo frame, alternating colors to create the board.

Optional: If you have a single color of foam, paint 32 of the 64 squares another color. Spray or cover these squares with a clear sealant to ensure the paint doesn't smear.