In 2024 I took a vibrations class for my engineering degree, and the professor expressed the need for a cost-effective, hands-on educational tool for students studying vibrations. The goal was to design a system that allows students to manipulate key vibration parameters, measure real-time acceleration, and compare experimental results with theoretical models—all while keeping the total cost under $100. The challenge was to create a compact, adjustable system that clearly demonstrates forced vibrations and resonance without requiring expensive lab equipment.
The result is a low-cost, interactive learning device featuring an adjustable unbalanced mass, smooth linear motion with magnetic stabilization, real-time acceleration tracking, and a variable-speed motor. This system enables students to explore forced vibrations, resonance, and frequency response in a controlled, hands-on environment, bridging the gap between theory and real-world application.
A key feature of the design is a 3D-printed wheel with adjustable mass placement, enabling students to change the excitation force and analyze how different force magnitudes impact vibration response. By adjusting the position of a bolt and nuts on the wheel, users can manipulate the forcing function and observe its effect on system behavior.
The motor module moves freely on linear rails, ensuring controlled vertical oscillations without unwanted side motion. Neodymium magnets placed above and below act like a spring system, passively stabilizing the motion. This eliminates the need for rigid constraints while providing a realistic vibrational response for analysis.
The combination of the adjustable mass, magnetic restoring force, and motor speed control gives students precise control over the system’s vibration characteristics, making it ideal for educational use. Additionally, the system is easy to build using common and inexpensive parts, ensuring accessibility for students and educators without requiring specialized equipment or manufacturing processes.
This system is designed to reinforce key concepts from vibration analysis, including natural frequency, resonance, and forced response behavior. Students can experimentally determine these parameters and compare them to predictions using standard vibration equations.
Unlike a traditional linear spring, the magnetic restoring force does not follow Hooke’s Law exactly. Instead, students must analyze how the force changes with displacement and determine an effective stiffness based on experimental data. This provides a more advanced challenge than simply plugging values into an equation, as it requires interpreting real-world nonlinear behavior.
While damping is often ignored in introductory problems, the linear bearings introduce a small but measurable damping effect, influencing how vibrations decay over time. This allows students to explore real-world deviations from idealized models and estimate damping coefficients through experimental observation.
Using an accelerometer and an Arduino-based data collection system, students can do numerous calculations based on theoretical and real-world data. They could measure and calculate parameters like peak response and resonance, compare experimental acceleration data with theoretical predictions, and analyze the phase difference between excitation and response. This hands-on approach helps bridge the gap between abstract equations and practical vibration analysis, reinforcing engineering intuition in a tangible way.
This system provides students with an intuitive, low-cost way to study vibration response, making it ideal for mechanical engineering courses covering structural dynamics, modal analysis, and resonance phenomena. The prototype and CAD design are currently in the possession of the professor for use in future lab sections.
There are some aspects that could be improved upon for future iterations.
A refined data acquisition system for real-time frequency response plots
Use a PWM motor controller for more precise motor control to fine-tune excitation frequencies
Adjustable damping elements to analyze realistic vibrational decay patterns
A larger version of this system could be used as an interactive shake table needed fo other experiments
First Prototype With Accelerometer Wire Routing
First Prototype With Accelerometer
First Prototype With Power Supply