Adapt-a-Grip

Welcome to the instructional guide for making your Adapt-a-Grip prosthesis device, a transradial prosthesis capable of attachment to various terminal devices. This guide will equip you with the knowledge and techniques necessary to construct a versatile and functional prosthetic device tailored to the needs of individuals with upper limb differences.

The Transradial Adapt-a-Grip prosthesis offers a unique blend of innovation and adaptability, featuring a body-powered capable socket for optimal limb fit and a quick disconnect wrist mechanism for effortless interchangeability between terminal devices. Five main types of terminal devices are described more thoroughly later in this report. Passive is the type that is commonly used for appearance to mimic the look of a missing limb. Body-powered is the type that has active movement through a cable system hooked up to the residual limb. Externally powered, an external power source powers it and adds active movement through electronics. Activity-specific is designed specifically for the movements performed during a specific activity or hobby. Furthermore, a hybrid terminal device is a combination of two of the previously described types.

The Adapt-a-grip prosthesis works with all five types and allows users to create various terminal devices that fit all their needs, improving their quality of life. This guide is a step-by-step process of fitting the Adapt-a-Grip prosthesis, 3D printing all parts, assembling the socket and wrist, and ensuring precision and reliability at every stage. Designing your own terminal devices and integrating them with the socket will be thoroughly explained, allowing you complete creative freedom to participate in diverse activities and interests, including specialized basketball, baseball, crocheting, and cycling designs.

Quick Disconnect Wrist and Socket Materials:

• PLA or ABS Filament
• 8x 8mm steel balls
• 4x 0.011” x0.16” x0.79” springs
• Micro Wire Cutters
• #4 pan head - sheet metal screw
• 2-part epoxy
• Sewing hook and eye closure
• Braided fishing line
• Velcro Strap
• Boiling Water/Heat Gun (one or other)
• Piece of craft foam (2mm thickness)
• Optional - sandpaper

Body-Powered Hand Materials:

• PLA or ABS Filament
• Braided fishing line
• Joints (one or the other below options)
• TPU filament (95A)
• Silicone caulking and cornstarch

This section describes the process of printing and assembling one complete Quick Disconnect Wrist for the Adapt-a-Grip prosthesis. The wrist mechanism plays a crucial role in allowing easy swapping between terminal devices, enhancing the adaptability and functionality of the prosthetic device.

There are three main parts of the mechanism: the connector, which attaches to the terminal devices and allows for integration into the socket; the quick-release mechanism, which consists of steel balls and springs inserted into a central part that attaches to the main socket; and finally, the hub which slides over the quick release mechanism and its parts, concealing everything for improved durability. 

1. Download the following files to prepare for printing.
2. Print the connector and hub parts using slicing software such as Cura using the following suggested settings.
3. Infill: 20%
4. Infill Pattern: Gyroid
5. Nozzle Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. No supports
8. Print the quick-release part using slicing software with the same suggested settings but added support.
9. Support Type: Tree
10. Placement: Touching Build plate
11. Once printed, remove all generated supports from the quick-release part using the microwire cutters.
12. Optional - Gently sand down any rough edges to prepare parts for assembly. 

** Wrist consists of three main parts, the hub, quick release mechanism, and connector. The hub serves as the central component where terminal devices connect. The quick release mechanism facilitates rapid detachment of terminal devices from the hub. Streamlines the process of swapping between terminal devices. Finally, the connector is the part that attaches to base of all terminal devices to allow for integration with the socket. **

1. Place one steel ball into each hole around the circumference of the printed quick release.
2. Place a spring into each hole on the top of the quick release. 
3. Maneuver the hub over top of the quick release. The top of each spring should slide over the cylindrical pieces on the top of the hub, securing the springs inside the hub to prevent them from popping out when compressed.

Download and Install OpenSCAD (on a Windows PC):

1. Create a file in File Explorer where all finished stl parts will be saved for printing.
2. Navigate to the OpenSCAD download page by visiting OpenSCAD - Downloads.
3. Once on the download page, click on the download link for your operating system to initiate the download process.
4. Follow the on-screen instructions to complete the download. Depending on your browser and settings, you may need to specify a download location or confirm the download.
5. Once the download is complete, locate the downloaded file (typically found in your Downloads folder) and double-click on it to begin the installation process.
6. Follow the installation prompts provided by the installer program. You may have to agree to terms and conditions, choose installation options, and specify the installation directory.

Fitting the Socket:

1. Due to large file size, to download OpenSCAD socket files complete the following extra steps.
2. Navigate to Thingiverse.com.
3. Search Kwawu Arm 3.0 - Socket Version.
4. Only necessary to download the Kwawu_3.0-_Socket.scad file.
5. After the installation, launch OpenSCAD by locating it in your list of installed applications or by using the search function on your computer.
6. Upon launching OpenSCAD, you should see the main interface of the software. Select Open, and when prompted, choose the Kwawu 3.0- Socket.scad file.
7. On the right-hand side of the screen is a Customizer menu where you can view and edit part dimensions by clicking the arrow next to Parameters.
8. Make sure Automatic Preview is checked.
9. Show Details should be selected.
10. An automatic preview of Cuff1 will be in the view window. Press the View All icon to resize the object so it is full screen.
11. It is time to take measurements; a flexible tape is an excellent tool. All dimensions are done using the residual limb, and since we only utilize the socket, the hand and wrist measurements are unnecessary.
12. Choose whether the socket is being created to replace a left or right arm.
13. Select the plastic option under the LeatherOrPlastic cuff.
14. The bicep dimension will be taken at the thickest point on the residual arm.
15. Arm length is to be taken from the bend of the elbow to just before the wrist on the intact arm.
16. The forearm circumferences are taken starting at the elbow bend, down to the end of the residual limb, every 25 mm.
17. Once all measurements for the socket portions have been edited, click Save Preset.
18. Once all updated measurements have been saved, the parts can then be rendered. Select each socket part listed below, hit the Render button, and finally, select the Save STL button and save the following parts in the previously created folder. 
19. Upper arm
20. Lower arm
21. Ratchet
22. Latch
23. Latch Cover
24. Elbow Bolt 1
25. Elbow bolt 2
26. Tensioner
27. Download the last updated socket cuff and move them to the previously created folder with the rest of the socket parts. Marked as "Cuff".

** Important: 5 Elbow Bolt_1s are required for the cuff assembly **

1. Print all files for the socket and cuff with the suggested settings. Check below to determine which parts should be printed with tree supports touching the build plate.
2. Infill: 20%
3. Infill Pattern: Gyroid
4. Printing Temperature: 210 ºC
5. Build Plate Temperature: 60 ºC
6. Use the microwire cutters to remove the supports from all parts.
7. Optional – Use sandpaper to clean up any rough edges on all parts to prepare for socket assembly.

• Supports
• Lower Arm
• Ratchet
• Tensioner
• Cuff

1. Attach the upper arm and lower arm parts with two-part epoxy. There is a notch on each that fits perfectly together to ensure they are attached correctly. 
2. Place the latch in the correct lower (off position) position, as shown in the picture.
3. The latch acts as a locking mechanism for the fingers of an attached body-powered hand, depending on the upper arm rotation.
4. Cut a piece of 2mm wire/hanger from the hole in the upper arm, through the latch, and into the latch cover.
5. Place the latch cover over the latch and screw it into place with the #4 Pan Head sheet metal screw. 
6. While the latch is still in the off position, place the ratchet over the upper arm knob. 
7. Check to ensure the latch engages when in the on position by sliding it up and seeing if it locks the ratchet in place.
8. Place the tensioner into the slot on the ratchet. It should easily fit on all sides when rotated. 
9. The tensioner is a way to tighten and increase the tension of the fishing line that connects the fingers to the socket.
10. Now, it is time to wire the socket. String a section of braided fishing line through the bottom hole on the socket, then out the hole right above it.
11. The line should be long enough to go past the ratchet.
12. String the wire up through the hole in the ratchet, then tie it to the tensioner's center hole. 
13. Tighten the tensioner as desired by wrapping the line around it, then place the line back into the slot on the ratchet. 
14. Finally, attach the first part of the sewing hook and eye closure to the base of the line coming out the bottom of the socket. 
15. Eventually, the tensioner string will be attached to the wiring system of the body-powered hand terminal device to create active movement.

1. Once printed, the cuff parts must be shaped to fit the user's natural arm shape. This is done by heating the parts using one of the following methods.
2. Heat Gun – Slowly heat the back side of each cuff part, forming it once malleable to the correct shape. 
3. Submergence in Boiling Water – Boil some water in a non-food pot, submerge the pieces, and form once removed. The parts are submerged for a couple of seconds before becoming malleable.
4. Once formed to the user’s arm, cut and attach a piece of foam to the pieces that will touch the user's arm. Basic 2mm thick craft foam provided sufficient padding for comfort.
5. Take the cuff arms and attach each to the corresponding side of the upper arm, securing them down with one of each elbow bolt size.
6. The longer elbow bolt is to go through the cuff, ratchet, and socket. 
7.  The Velcro strap can now be threaded through the cuff and prepared for use. 
8. Make sure the loop side of the Velcro strap will face the user to ensure comfort.

1. Using the two-part epoxy, attach the base of the wrist (bottom of quick release) to the base of the lower arm of the socket. 
2. Take your time to avoid any leakage if some epoxy leaks through the mating area, a wet rag or Q-tip can easily clean it up.

You have now completed the fitting, design, printing, and assembly of the Adapt-a-Grip socket. The next step is to start making or designing your own terminal devices to be utilized with the socket. Remember that the Adapt-a-Grip socket can be used with all five standard types of terminal devices, each with its benefits. Instructions on creating your own terminal devices that integrate with the socket are also included.

What are they?

A terminal device is the part of a prosthesis that interacts with people and things, allowing the user to mimic the look of a hand, manipulate objects, or perform specific tasks.

 Five Main Types

1. Passive – Usually for appearance, although they provide some form of stability. However, they have no active movement that would allow for the manipulation of objects.
2. Activity Specific – Designed for a particular activity to allow easy participation. They also prevent the everyday terminal devices from getting damaged in these specific activities (playing sports for example).
3. Body-powered – Include a cable system that allows users to manipulate the device through movement in the residual limb. It is commonly a hand or hook design that can open and close to grasp objects.
4. Externally Powered – Powered externally via batteries and motors, capable of moving without using the residual limb. There are two main types - single motor and multi-articulating devices such as a hand that can move each finger separately.
5. Hybrid – Combination of two of the previous types, optimizing the benefits of the terminal device. 

Design Your Own

Creating custom terminal devices tailored to your specific needs and interests is possible. This customization process involves modeling the desired terminal device and integrating it with the connector from the wrist mechanism. There are two main approaches to creating your own terminal devices. 

One approach is to model the terminal device using 3D design software, incorporating the connector from the quick disconnect wrist. Once the design is finalized, users can simply 3D print the terminal device with the connector attached to its base. This streamlined method allows seamless integration and ensures a secure connection between the terminal device and the wrist mechanism.

Alternatively, users may print the terminal device and connector separately and then use a two-part epoxy adhesive to attach them securely. This method offers flexibility in design and allows for experimentation with different materials and configurations.

Once the 3D-printed design is attached to the connector from the wrist mechanism, it instantly becomes a functional terminal device ready for integration into the adaptable socket of the Adapt-a-Grip prosthesis. This seamless integration allows users to effortlessly swap between different terminal devices based on their specific needs and activities.

Whether it is a specialized terminal device for sports, hobbies, or everyday tasks, the Adapt-a-Grip prosthesis offers versatility and customization to meet the diverse needs of users. By simply attaching the 3D-printed terminal device to the adaptable socket, users can instantly enhance the functionality and usability of their Adapt-a-Grip prosthesis, empowering them to engage more fully in their daily lives and activities.

Several activity-specific terminal devices have been designed and can be printed for use with the socket. Below are the details for each terminal device, along with instructions on how to download and print them.

Basketball Terminal Device - Designed to enhance grip and control for basketball players.

1. Download the basketball terminal device file attached.
2. Load the downloaded file into your preferred slicer software and print with the suggested settings.
3. Infill: 50%
4. Infill Pattern: Gyroid
5. Nozzle Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. Support type: Tree supports touching the build plate only

Baseball Terminal Device - Designed to hold and throw a baseball.

1. Download the baseball terminal device file attached.
2. Load the file into your preferred slicer software and print with the suggested settings.
3. Infill: 50%
4. Infill Pattern: Gyroid
5. Printing Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. Support type: Tree supports touching the build plate only

Cycling Terminal Device - Designed to attach to the handlebar of a bicycle to provide stability. 

1. Download the cycling terminal device file attached.
2. Load the file into your preferred slicer software and print with the suggested settings.
3. Infill: 50%
4. Infill Pattern: Gyroid
5. Printing Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. Support type: Tree supports touching the build plate only

Crocheting Terminal Device - Designed to allow users to crochet with various-sized crochet hooks.

1. Download the crochet terminal device file attached.
2. Load the file into your preferred slicer software and print with the suggested settings.
3. Infill: 50%
4. Infill Pattern: Gyroid
5. Printing Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. Support type: Tree supports touching the build plate only

By following these instructions, users can easily download, prepare, and print the activity-specific terminal devices, ensuring optimal performance and compatibility with their Adapt-a-grip prosthesis.

1. Download all the files below.
2. Load the Palm Cover, Palm, and Fingers files into your preferred slicer software and print with the suggested settings.
3. Infill: 50%
4. Infill Pattern: Gyroid
5. Nozzle Temperature: 210 ºC
6. Build Plate Temperature: 60 ºC
7. Support type: Tree supports touching the build plate only
8. Use micro wire cutters to clean up all parts by removing supports.
9. Optional to gently sand down all parts and edges to clean them up.

Now it is time to create the flexible joints that are used to attach the distal, middle, and proximal finger parts together and finally all the fingers to the palm. There are two main methods I tested out and found suitable for creating these joints.

1. TPU filament - Can be hard to print with on 3D printers that have the Bowden extruder. However, can be done with the following settings.
2. Infill: 100%
3. Nozzle Temperature: 220⁰C
4. Build Plate Temperature: 60⁰C
5. Print Speed: 20 mm/s
6. Retraction Distance: 3 mm @ 20 mm/s
7. Oogoo Mixture - Made of silicone caulking and corn starch. The process can be messy but is less time consuming.
8. Download and 3D print finger joint molds out of PLA with suggested settings below.
9. Infill: 50%
10. Infill Pattern: Gyroid
11. Nozzle Temperature: 210 ºC
12. Build Plate Temperature: 60 ºC
13. Mix a 1:1 mixture of silicone caulking and cornstarch. Use a well-ventilated or outdoor space.
14. Press mixture into molds, making sure it goes through both sides of the mold to ensure complete joint creation.
15. Let molds dry for about 4 hours.
16. Remove the joints from the molds and they are ready to be used.

Now it is time to assemble the hand.

1. Slide the corresponding sized joints into each slot of the fingers, connecting the distal to the middle, middle to the proximal, and finally the proximal to the palm of the hand.
2. Thumb only has one joint as it consists of a distal and proximal joint.
3. Slide fishing line down through the top of each finger making a loop with the two holes at the top of the distal fingers. This loop is used to tie off the wire and secure it in place.
4. With the remaining long end of the fishing line, string it through the holes of each finger piece and down through the palm.
5. Tie all the strings to the primary and secondary Whipple trees as shown in the sketch.
6. Attach the final string to the control hole of the secondary Whipple tree. Attaching the second part of the eye hook (previously used in the socket creation) to the end of the string.
7. Final step is to adhere one of the 3D printed wrist connectors to the base of the palm. Creating a body powered hand that can be integrated into the socket.

When attached to the eyehook of the socket, the user can bend the residual limb, thus bending the cuff and creating the grasping and opening movements of the hand. To get optimal movement, loop the string till taut around the tensioner, just until the tensioner can barely slide into place on the ratchet.

In conclusion, this instructional guide serves as a valuable resource for individuals seeking to assemble an adaptable transradial socket utilizing the open-source Kwawu 3.0 socket design and the open-source Flexy Hand fingers. The opensource designs were a great help to the project and can be found on Thingiverse, I highly recommend checking them out. It's crucial to emphasize that this guide is not authored by a professional prosthetist, and the resulting arm should be regarded as an assistive device rather than a custom prosthetic. Users are reminded that the utilization of the information and resources provided herein is solely at their discretion. By proceeding, users absolve the author of this document of any liability, understanding the DIY nature and potential limitations of the device. All future updates will be made on this document.