Jordan PraxEngineering Portfolio

Projects

Engineering projects, start to finish

What I designed and built, how it was tested, and what changed as a result.

Overhead view of the built fixture on a cutting mat inside an aluminum extrusion frame. A stepper motor with a white printed spool sits in a black L-bracket; the bracket is bolted to a white printed adapter, then a silver S-shaped load cell, then a second white printed adapter fixed to the extrusion. A braided cord runs from the spool up the length of the frame.
PhotographThe tested fixture from the knee-traction project: motor and printed spool on an off-the-shelf bracket, with the load cell in the motor's reaction path between printed adapters on a T-slot frame.

Featured project · Personal project

Knee Traction Prototype

Technology demonstrator · bench-tested

An electromechanical knee-traction prototype: a microcontroller drives a stepper motor that pulls a cable, and a load cell in the force path feeds closed-loop force-limit logic that stops the motor at a set tension. The work spans electromechanical and embedded electronic design, from a cardboard mockup on a leg to a rigid, instrumented bench fixture tested under load.

Work involvedElectromechanical design · Embedded electronics and firmware · Mechanical design and CAD · 3D-printed interfaces · Load-cell sensing · Fixture design · Bench testing

Read the case study
Patent line drawing of the height-of-cut mechanism in exploded view: from top, a ribbed cap, a perforated locking plate with two pins, a ribbed handle, a snap ring, a long threaded screw, an outer cylinder with a square mounting tube and a bent mounting arm with bolts, an inner cylinder, bushings, a small connector screw, a shaft with height markings, a caster yoke, and a caster wheel.
Patent figureThe mechanism, exploded. FIG. 2, U.S. Patent 12,635,602 B2 (Deere & Company).

Case study · Professional work

Z998R Height-of-Cut Mechanism

John Deere · contract engineer through RFA Engineering · in production · patent co-inventor

A height-of-cut adjustment mechanism I conceived and was the primary designer for, now in production on the John Deere Z998R Diesel ZTrak™ Zero-Turn Mower: CAD and GD&T, tolerance and failure analysis, prototypes, controlled impact testing, and supplier development.

Work involvedMechanism design · CAD · GD&T · Tolerance stacks · FMEA / DFMEA · FEA (SimSolid) · Prototyping · Impact testing · Supplier development

Read the case study
Side view of the finished three-wheeled vehicle in a workshop: steel tube frame, a seat with a short back, a rear basket, foot pedals mid-frame, and a raised hand crank with a chain to the front wheel.
PhotographBeta prototype, 2019. From the team's design report.

Case study · University team project

Adaptive Human-Powered Vehicle

James Madison University · 2018–2019 · team of nine

A human-powered vehicle designed around one rider's abilities and goals: client-driven requirements, a weighted concept selection, center-of-mass and frame analysis, subsystem proofs of concept, and alpha and beta builds. The client chose it as his final vehicle. I contributed to the mechanical design and took the lead on prototyping.

Work involvedHuman-centered requirements · SolidWorks · Frame and center-of-mass analysis · MATLAB · Welding and machining · Subsystem integration · Prototype testing

Read the case study
A light-blue square platform covered in a grid of large round blue studs, with a yellow block and a blue block placed on top. The platform sits on a workbench.
PhotographThe proof of concept: large LEGO-style blocks on a studded platform.

Case study · University team project

Adaptive Musical Instrument

James Madison University · working proof of concept

A proof-of-concept instrument for an elementary-school student with a disability, played by placing large LEGO-style blocks on a platform. The input moved from buttons to light sensing so a placed block was enough. I contributed across concept, requirements, mechanical design, software, assembly, and testing.

Work involvedHuman-centered requirements · SolidWorks · Light sensing · Microcontroller · C++ · Prototyping and testing

Read the case study
Block diagram titled Simulink Model. Accelerometer and GPS data feed a raw-data block and a MATLAB computational script, then a linearized track; geometric data enters through a Simulink import. Inside the model, battery feeds drivetrain with electrical energy, drivetrain feeds chassis with mechanical energy, and the outputs are kinematics, performance, and losses.
DiagramThe Simulink functional model: what data comes in, how energy moves between the battery, drivetrain, and chassis, and what comes out. From the team's May 2020 capstone report.

Case study · University team project

Shell Eco-Marathon

James Madison University · two-year capstone · 2019–2021 · team of six

A fuel-efficiency prototype vehicle, approached first as a system to model. On the strategy team I helped build a MATLAB/Simulink model to inform driving strategy and design decisions, owning the criterion that the vehicle's structure be a model parameter. When COVID-19 ended the handoff from the senior team, the project grew to include the car, and I took on mechanical drivetrain design from the engine to the wheels.

Work involvedVehicle systems · MATLAB / Simulink · Mathematical modeling · Requirements · Concept selection (AHP) · Drivetrain design · Troubleshooting and testing

Read the case study

01Selected work

Selected engineering work

  1. Porsche 944

Detailed write-ups for these projects are being reconstructed from their original records, and each will be published once that's done.