This page details the assembly of the knee prosthesis. To complete this step, you need an assembled thigh, shank, motor, GCS, and microcontroller module. These modules are integrated with various transmission components, fasteners, and wires, to construct the knee prosthesis. After completing steps 1 to 5 on this page, you will be ready to test initial subsystems of the knee prosthesis. Step 6 should be completed after performing initial testing of the motor system.
Step 1: Main Electronics
This step details the installation of the microcontroller, the USB extender, and the E-stop connector. To complete this step, you will need two M2.5 x 14 mm socket cap screws, small pieces of tape, the micro-usb extender, and the barrel jack cable. The installation requires the use of a 2 mm Allen wrench and a Phillips screwdriver.
Step 2: GCS Sensors
This step details the installation of the TLV493D magnetometer sensors that are used to determine foot contact with the ground. To complete this step, you will need four M2.5 x 14 mm socket cap screws and small pieces of tape. The installation requires the use of a 2 mm Allen wrench.
Step 3: GCS Beam Element
This step details the installation of the GCS beam element. To complete this step, you will need six M4 x 60 mm button head screws and washers, four M6 x 25 mm flat head screws, and four M6 square nuts. The installation requires the use of a 2.5 and a 4 mm mm Allen wrench.
Step 4: Secondary Gear Stage, Thigh Frame, & Joint Encoder
This step details how to install the thigh frame, the secondary transmission stage (i.e. gear train), and the main joint encoder. To complete this step, you need an assembled thigh frame, a cut 1/2" hexagonal shaft, the 45T gear, a spare piece of 0.375" hexagon shaft, the 18T gear, the 0.375" 3D printed shaft spacer, the 0.375" shaft collar, and a TLV493D sensor. You will also need needle nose pliers, a Phillips screw driver, and a hammer. A 3/32 inch Allen key can be used to tighten the shaft collars (not filmed). The 52T gear glued to the 0.375" steel shaft can be installed instead of the spare 0.375" shaft. However, it is advised to test the motor (see Control Section) with the knee joint disconnected (i.e. 52T gear removed).
Step 5: Motor Module
This step details the installation of the motor module onto the shank frame. To complete this step, you will need an assembled motor module, a printed motor module wire cover, 4 M4 x 60 button head screws and washers, and tape. You will need a 2.5 mm Allen Wrench to install the screws.
Step 6: Final Gear Install
The 52T gear and shaft (assembled in step 2 of Motor and Transmission Module) is not initially installed. This means that the motor is disconnected from the main joint and allows for initial systems testing without damaging the motor, transmission, or frame components. When ready, you can install the 52T gear and shaft assembly.