Drop Tower Systems

Summary

Drop Tower Systems focuses on the design and development of a low-cost drop weight impact tower for UCI Engineering. The system addresses the current lack of an in-house method for applying controlled dynamic loads to materials and components, as existing campus equipment is primarily limited to quasi-static hydraulic load frame testing. This project matters because many real-world engineering applications, including aerospace composites and automotive structures, involve impact and dynamic loading conditions that static tests cannot fully capture.

The final design is a 52.5" tall, wood-framed tower capable of delivering up to 100 J of impact energy through a guided 12"×12" A36 steel drop weight plate and an A2 tool steel tup with hemispherical geometry compliant with ASTM standards. The system supports variable impact energies through both adjustable supplemental weights, up to 22.5 lbs of total drop weight, and a simple rope and lock mechanism that allows drop height to be set anywhere up to one meter. Key subsystems include an electromagnet release mechanism with passive safety latches, and a fully self-contained data acquisition system built around a Teensy 4.1 microcontroller, a high-g accelerometer, and a photointerrupter velocity gate, all battery-powered with no external wiring required during testing. The system is intended to support students, faculty, and competition project teams by providing a safer, more repeatable, and more accessible platform for validating components and materials under realistic dynamic loading conditions.

Technical Approach/Methodology

Our team is solving this problem by designing and building a configurable drop-weight impact tower that can apply controlled dynamic loads to a variety of test samples. The system combines a 2x4 lumber and plywood structural frame, hardened steel guide rails with precision linear bearings, a 12"x12" A36 steel drop weight plate with adjustable supplemental mass, an A2 tool steel tup compliant with ASTM D5628, an electromagnetic release mechanism, passive safety latches, and a rope and lock system for setting drop height. We used formal engineering design methods throughout the project to compare concepts, select materials and components, define functional requirements, estimate cost, and ensure the machine is safe, repeatable, and practical for students and researchers to use.

Tools and methods used in the project include CAD-based design and tolerance analysis, material trade studies, vendor sourcing, and subsystem-level testing. For data acquisition, the system uses a Teensy 4.1 microcontroller paired with a high-g accelerometer and a photointerrupter velocity gate to measure impact force and drop velocity, logging data directly to an onboard SD card with no external wiring required during testing. Performance targets and tup geometry were defined in accordance with ASTM D7136, ensuring the results the system produces are meaningful and comparable to established testing standards.

Outcomes

Our team produced a functional prototype of a low-cost, drop-weight impact tower designed to apply controlled dynamic loads to materials and components for UCI Engineering. Over the course of the project, we completed a full problem definition and requirements document, stakeholder interviews, system-level diagrams, CAD models for all subsystems, material and component trade studies, and a finalized bill of materials. Manufacturing is complete, with the structural frame, drop weight plate, tup assembly, and electronics housing all fabricated and integrated into a working prototype. The total project cost came in just over the $500 budget, achieved through in-house machining, sponsored materials, and careful component selection.

Specific deliverables include the fully assembled impact tower with a 2x4 lumber and plywood frame, a guided 12"x12" A36 steel drop weight plate with adjustable supplemental mass, an A2 tool steel tup compliant with ASTM D7136, an electromagnetic release mechanism with passive safety latches, a rope and lock system for variable drop height up to one meter, and a self-contained data acquisition system using a Teensy 4.1 microcontroller, high-g accelerometer, and photointerrupter velocity gate. Supporting deliverables include full CAD documentation, a design report, test results demonstrating repeatable dynamic impact performance, and operating and safety documentation for use by future students and researchers.

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