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There is still a demand for novel laboratory equipment designs that are to be utilized in undergraduate level machine dynamics, mechanical vibrations, control theory and their related labs. Since the turn-key systems preferred in most undergraduate labs are expensive and require wide lab space, 3D printed portable, small scale and cost-effective vibrational lab equipment are designed to study the fundamentals of free and forced vibrations. Four laboratory equipment designs are proposed in this study to demonstrate the fundamentals of vibration such as free vibration, forced vibration, modeling, base excitation and vibration isolation. The first device is a vibration isolator and resonator mechanism incorporating large deflecting fixed-free flexible links and composed of primary and secondary masses and a linear actuator, the second mechanism is a compliant parallel arm consisted of flexible beams, mass and a support, third mechanism is a translational vibratory mechanism comprised of slider carts, 3D printed springs, rods and bearings and the final mechanism is the model of driver seat consisted of DC motor, driver and driven wheels and a mass. Main parts of each apparatus are built by 3D printing using either PLA or PETG filament. Learning outcomes and the methods of implementing each device to the course and their associated laboratories are provided.

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This study presents the design and development of a tendon-driven soft gripper manipulated by a 4 DOF robotic arm. The proposed robotic arm and gripper explore new areas focusing on increasing the grasping performance of the gripper as well as the workspace. The gripper is designed with 3 fingers and driven by tendons using two servo motors. The tension of the strings is adjusted using a pulley mechanism and a string. The opening and grasping of the soft gripper are accomplished by each motor. The wide opening allows the gripper to grasp larger objects. The parallel robotic arm motion is actuated using 4 motors. These motors are mounted on a spherical shoulder plate with attached circular plates with angled axles are. The axles are angled so that their axes of rotation converge to the center point of the shoulder plate. The vertical and lateral motion of the robotic arm is controlled by the series of radial linkages connected to the motors, with a parallel linkage attached to the radial linkages to actuate the forearm of the mechanism. The robotic arm is 3D printed in polylactic acid (PLA) and the monolithic soft gripper is 3D printed in thermoplastic polyurethane (TPU). The gripping force applied by the gripper is obtained using flexible sensors attached to the tip of the 3 fingers. The finite element analysis is performed in SoldWorks and the link lengths are optimized to trace the desired workspace. The mechanism is tested for its grasping and lifting of various objects showing promising superiorities in terms of its grasping capabilities mimicking the human hand. If the robotic arm is mounted on a moving platform, then it can serve as an assistive robot for the elderly.

Undergraduate mechanical engineering students struggle in comprehending the fundamentals presented in an introductory level mechanical vibrations course which eventually affects their performance in the posterior courses such as control theory. One salient factor to this is missing the visualization of the concept with hands-on learning since the vibrations and control laboratory course is offered in the following semester. This study presents the design, development of three portable and 3D-printed compliant vibratory mechanisms actuated by a linear motor and their implementation in vibrations course and vibrations and control laboratory. The proposed setups consist of flexible and compliant springs, sliders, and base support. Mechanisms are utilized to demonstrate free and forced vibrations, resonation, and design of a passive isolator. In addition to the 3D-printed, portable lab equipment, we created the Matlab Simscape GUI program of each setup so instructors can demonstrate the fundamentals in the classroom, assign homework, project, in-class activity or design laboratory.