IV. The Manufacturing and Assembly

The pins, caps, joint/motor mount, and links were all 3D printed on Phillip's Ender 3 using white PLA. We did not take any pictures during the printing or the assembling of the parts, so we will give a brief overview of the assembly.

The links were the first parts to be printed, followed by the joint/motor mount, and then the pin joints. The circular plate with the pin (Figure 3) was then glued to the motor fin. The middle hole of joint/motor mount was filed down to widen the hole. The hole needed to be wide enough so that the motor fin could attach to the motor and rotate freely without being constrained by the mount. The ternary links were designed to hold the ball bearings. The holes for the bearings were filed down so the bearings will press fit into the linkages. The ternary links were mounted to both sides of the joint/motor mount. When attaching the links to the circular plate with the pin, the stacking links caused some height discrepancies within the prototype. To account for this, the links attached to the pin on the circular plate were arranged in a specific order, that way none of the linkages were slanted or in tension.  

Figure 12: Assembled Prototype After Rearranging Links For Height Compensation