Introduction: Prothestic Hand
This prosthesis has been designed to help those people with missing fingers.
It has been modelled keeping in mind the following principles:
- Keep the number of printed parts as low as possible. -Keep the assembly process as simple as possible.
- Use the least possible amount of non-printable parts. In this new model, you can choose how to join fingers, using screws (2M), axes wire, or filament printer. Leave openings in the model to allow the hand to transpire.
- The previous model had another hand rotation system on the wrist, had more freedom. On this occasion I have modified the movement of the wrist using the fantastic idea of a union that uses hand "Flexy-hand v2"
- I have also modified the system of tensioning the strings. It is safer than before and takes up less space.
I have included a version without thumb for those who have their own finger.
The fingers flex when they are pulled by strings, such as fishing line, and extend automatically with the help of elastic cord. A fabric strap with velcro is needed to secure the prosthesis to the arm.
You can download the original file blender, and thus can be studied and modified to improve its performance.
This design is based on my previous design.
You can download and view files here: http://www.thingiverse.com/thing:1489003
Step 1: Materials
- Printed pieces
- Soldering iron
- Choose the connection system parts between:
- Filament printer (1.75mm)
- Screws and nuts M2 10x20mm and 10x10mm. And superglue to fix the nuts.
- Wire and filament printer
- Fishing line
- Elastic cord 1mm diameter
- Velcro strip
Step 2: Joins Parts: Wrist and Hand
La pieza de conexión debe ser flexible. Para imprimir esta pieza utilicé filamento flexible "filaflex".
The connecting piece must be flexible. To print this piece I used flexible filament "filaflex"I have also used flexible filament thus provides better grip for objects, although in this case is optional.
Step 3: Jointing Together the Pieces of the Fingers.
Choose how you want to join fingers. I'll show you three options:
- With screws and nuts M2 10x20mm and 10x10mm. And superglue to fix the nuts.
- With Wire and filament printer
- or Only with filamentof printer (1.75mm)
The easiest option is with nuts and bolts, but if you do not have to hand can use the other two ways union. As you will see in the video finally to join the fingers, I chose the option filament wire.
This is the order to assemble the fingers:
- Insert the elastic cord in "distal" piece.
- Join "link" piece.
- Enter the link piece and the elastic cord in the "proximal" piece.
Make sure that the elastic cord is on the outside.
The middle finger is the first finger should be placed, then put the ring finger. The order of the fingers is not important in the assembly.
Step 4: Places the Cords in Hand
In this video image and you can see how easy it is to place the cable. Depending on the fishing line you use, you may need help with a wire insert.
The elastic rope is tied in the palm of the hand. The non-elastic cord is attached to the wrist using pieces "tension". Only you need to tighten the strings to your taste and place the cover to let them fixed.
Step 5: Velcro
Uses Velcro to attach the hand to the wrist. Velcro with adesivo is very comfortable for it.
Velcro 40 mm wide will be perfect. Also, you can find it in different colors.
The hand is finished