Our goal for this prototype was to create a personal prosthetic that could replace the looks and and grapping function of the original hand. In order to get a good prosthetic there are several ways of copying the 3D surface of a hand. In our DIY model we made use of clay moulds. If you have the access to a 3D surface scanner this will of course be more preferred, as it can reach a higher level of detail in less time.
Step 1: Clay Mould
The first step to create your new hand is make a mould in clay. This has been done by wrapping clay around all the parts of your hand without moving them. Keep in mind that the position of your hand during this stage is crucial for your final product.
Step 2: Melt Candle Wax
The second step is to melt candle wax. This candle wax will become the basis of your final design.
Step 3: Fill Clay Mould
The third step is to poor the molten candle wax into the clay mould. Creating an exact copy of your hand. (If done right.) We recommend pouring the wax in layers into the mould, considering the time for it to set. After the entire mould has been filled and the wax is completely solid again. The next step can be done.
Step 4: Wax Model
Step four. You remove the clay layer around your wax hand. Now you can use your hand model to make several personal prosthetics. For example, wrapping fingers, creating a brace for the thumb, re-adjust surfaces of the hand or add extra parts. In our example we decided to create a grabbing hand.
Step 5: Plaster
The next step we did was wrapping the model in plaster bandages. To get a hollow hand as a result. Allowing us to integrate a grabbing mechanism into the hand. The mechanism we chose for this example was an ordinary waste grapple.
Step 6: Integrate Grabbing Mechanism
The next step was to integrate this mechanism. We choose the thumb as moving limb, in order to be able to grab things. Therefore, the thumb had to be detached from the rest of the hand.
Step 7: Reassemble Thumb
After this, the thumb was reassembled on the waste grapple, which enabled the hand to grab objects.
Step 8: Done!
We hope this project will inspire you to create all sorts of custom made prosthetics and how to easily do it yourself without a 3D scanner!