Custom Prosthetic Arm

We are creating a prosthetic arm design for a mannequin without arms.

Materials

Balsa wood (4 pieces about arm's length bc of arm reasons)

Wooden dowel (2x the length of your arm)

Wielding wire or any flexible wire

Foam/ styrofoam

Pipe cleaners

Other wooden pieces and bits (you will need a decent amount)

More foam

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Tools

Drill (2 bits: a bit for the dowels and a thinner bit for the wire)

Hot glue

Handsaw

Sandpaper

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I did this in a group so you may need to make compromises and changes based on ideas that were made. The arm can vary but this Instructable is just giving guidelines and a general way to make the arm.

Glue 4 pieces of rectangular prism shaped wood together and one square shaped piece of wood in a big square. You could also glue 9 square prisms of wood together. We glued them in a formation like so:

‎ 🟥🟥 🟧

🟨 🟩 🟧

🟨 🟦🟦

we started with a corner like by gluing the blue and yellow to the green, then layering red and orange.

It doesn't have to be perfect but the wood should be strong and thick. You could also just use a strong and thick piece of wood if you think it's sufficient.

For the prosthetic "flesh" of our arm we used foam to cover the stick.

You can use any material you see fit. We tested out cardboard, but we still stick with foam.

we made sheets of foam surrounding the main stick in a formation like so

‎ 🟧🟧🟧

🟨 🟩 🟥 (green is the "Bone" stick)

🟦🟦🟦

Then glue them onto the stick.

Probably the most fun part of the arm.

First cut and trim a block of wood, or glue multiple pieces together.

Drill 5 holes where you want to put the wire/ finger "bones" in

Cut them

Then cut 5 pieces of wire, each a couple inches longer than the total length of all three finger parts

Afterwards "thread" the pieces through and wrap some pipe cleaners around each join, adding fro some cushioning.

The Elbow of the design is quite simple.

All you need is a drill and drill bit that has the same circumference as the wooden dowel or any rod that you have.

Trim the rod and make an indent for the end/ stoppers if needed.

Drill a hole and then attach end/ stoppers to the endpoint of the dowels on each side.

You could also make some dents and make the stoppers flush with the arm.

Make a block of wood that's about as thick as the hand you made, but not quite as wide. Make it as long as you want (preferably wrist length)

Then drill a hole through it for the wire to go through.

Put the wire in the hole, the wire should be longer than them, and go all the way through and more by a few inches.

Drill a hole in the "Bone" of the arm, and in the hand.

Then put some hot glue in both the holes.

Plug the wire in.

You could also use more wire if you don't want it to spin.

You could add a block of foam for a shoulder pad, as it helps with covering the attaching of the arm.

But to attach the arm:

Drill a hole in the arm, the thickness of the wooden dowel

Then drill another hole perpendicular from the inside of the arm

Make a loop with the metal wire (don't cut the wire just yet, you still need to wrap it around the neck)

Put the looped wire into the 2nd perpendicular hole you made, aligning the loop to the other hole like shown in the diagram

Insert the dowel into the first hole, "threading" it into the loop midway through the hole, and out the other end.

Add stoppers on either side, and like before you can choose to make it flush to the arm.

paint the "arm"

Make wrap the other end of the looped wire and loop it around through inside and out the subject of the matter requiring an arm. Add a strap of whatever to cover the wire so it's not as noticeable. There you go! A really nice arm that 'can' move!