Mechanical Test Engineer
3 days ago
Palo Alto
Role Overview We need three hands-on, mechanically oriented Test Engineers who thrives in our test lab. This role balances: • Logistics layer - coordinating with design counterparts, collecting samples, creating JIRA tickets for technicians, and managing test sample logistics., • Hands-on test engineering - designing, building, and iterating on test setups., • Ownership mindset - treating each setup as if it were their own business, balancing speed, safety, and standardization in a fast-paced environment. Role Overview We need a hands-on, mechanically oriented Test Engineer who thrives in the lab. This role balances: • Logistics layer - coordinating with design counterparts, collecting samples, creating JIRA tickets for technicians, and managing test sample logistics., • Hands-on test engineering - designing, building, and iterating on test setups., • Ownership mindset - treating each setup as if it were their own business, balancing speed, safety, and standardization in a fast-paced environment. Key Responsibilities & Skills 1. Design & Build of Test Fixtures • Architect, model, and assemble frames (e.g. 80/20, steel, aluminum, composites) to house power systems, control electronics, and devices under test., • Design and build custom control boxes (e.g. microcontroller / relay / switching boards) to actuate and monitor test logic (for example, cycling chargeport latches)., • Create harnessing from control box to devices (wiring, connectors, cable management)., • Select and integrate components: power supplies, pumps, sensors, relays, data acquisition modules., • Rapid CAD design (SolidWorks or equivalent) of parts, assemblies, and fixtures., • Develop control scripts (Python preferred) for device actuation, chamber/chiller coordination, power cycling, data logging, error handling, interlock logic., • Decompose build and inspection tasks into JIRA (or equivalent) tickets, assign to technicians, and supervise execution and QA. 2. Mechanical Systems & Thermal / Structural Design • Choose pumps, heat exchangers, motors, actuators (servo, stepper, etc.) appropriate for the thermal, flow, mechanical load of the DUT., • Design structural supports, fixtures, mounting surfaces, force-transmitting links, and vibration isolation, considering stiffness, thermal expansion, alignment tolerances, and safety margins., • Apply GD&T (Geometric Dimensioning & Tolerancing) to ensure fixture elements match tolerances and reduce mismatch / rework., • Fabricate custom parts (machining, cutting, bending, welding) or coordinate with external machine shops when needed., • Understand mechanical stresses, thermal expansion, material selection (e.g. aluminum vs. steel, coefficient of expansion) to preserve alignment under extreme conditions., • Recommend and integrate mechanical stress/load elements (e.g. clamping, thermal cycling effects, flexures) for realistic loading of bus bars, junction boxes, chargeports. 3. Electrical, Instrumentation & Signal Integrity • Interpret datasheets and performance specs of HV components (contactors, shunts, relays, power converters)., • Size wiring harnesses (gauge, insulation, derating), design noise mitigation (shielding, twisted pairs, grounding), and design simple circuits (e.g. resistor dummy loads, balancing circuits) to support test logic., • Integrate measurement hardware: NI DAQ systems, thermocouples, RTDs, pressure sensors, accelerometers, current & voltage sensors., • Incorporate HV safety features: interlocks, watchdogs, fault detection, safe sequencing, insulation monitoring, and emergency shutdown paths., • Ensure signal timing, synchronization, sample rate, and data integrity across instrumentation channels. 4. Equipment & Test Facility Integration • Work with environmental chambers: plan safe ramp-down sequences (e.g. humidity first), account for thermal soak and enclosure constraints., • Interface with chillers / cooling systems to integrate temperature setpoints into test profiles and manage coolant circulation., • Use advanced / bi-directional power supplies (grid simulators, programmable sources) with SCPI, CAN, GPIB, Ethernet, LXI or RS-232 protocols., • Manage rack systems: power supplies, controllers, cabling, cooling, harness routing, cable length constraints., • Configure and validate test stands to maintain safety clearance, mechanical access, serviceability, and reliability over long test durations. 5. Reliability & Environmental Testing Expertise • Understand and design for reliability test methods common in EV and power component space:, • PTCE (Powered Thermal Cycling Endurance), • HTOE (High Temperature Operating Endurance), • HTHE (High Temperature Humidity Endurance), • IP (Ingress Protection / environmental sealing tests), • Develop or adapt fixtures and setups for these tests (thermal cycling, humidity, load cycling) and interpret resulting data for degradation / failure modes., • Use test data and models to accelerate test times (e.g. using real-world load profiles) while maintaining statistical confidence., • Understand aging, fatigue, electromigration, thermal cycling cracks, insulation breakdown, corrosion or humidity-related degradation patterns as inputs to design feedback. 6. Validation, Calibration & Fixture Quality Assurance • Validate fixtures: check alignment, clearance, actuation, contact integrity, wiring, and signal continuity., • Perform fixture checkout and verification prior to production test runs (probe hits, wire verification, interlock tests)., • Maintain calibration schedules for sensors and instrumentation to ensure accuracy over long-term usage., • Monitor fixture drift, failure modes, and redundancy in critical paths (spare sensors, fallback mechanisms)., • Design with safety in mind: include grounding kits, proper shielding, and ensure human safety in presence of HV. Target Industries for Candidates • Automotive (EVs, Tier-1 suppliers in power electronics, HV systems), • Aerospace/defense (environmental test, reliability), • Industrial power systems (HV equipment, grid simulation, power distribution), • Electronics testing labs with fixture design/validation experience Pre-Screening Questions (with examples of good answers) • Can you describe a time you designed and built a custom test fixture from scratch?, • Follow-up: How did you choose pumps, power supplies, sensors, and framing?, • Follow-up: How did CAD and scripting factor into your solution?, • Good answer: Candidate explains building a fixture using 80/20 framing, a relay-controlled PSU with Arduino, custom harnessing, and Python scripting for cycling and logging data., • In an 85°C/85%RH environmental test, what do you ramp down first before opening the chamber?, • Good answer: Humidity first, otherwise condensation risks damaging the samples., • How would you reduce electrical noise in a setup with HV and LV wiring running together?, • Good answer: Separate HV and LV harnesses, use twisted pairs, shielding, and proper grounding., • How do you decide what pump, heat exchanger, or motor to use in a thermal or mechanical test setup?, • Good answer: Candidate refers to flow/pressure/heat load calculations, safety margins, and equipment specs matched to test needs., • Tell us about your experience with instrumentation (DAQs, thermocouples, accelerometers)., • Good answer: Candidate describes specific examples of DAQ integration, sensor calibration, and how they analyzed and communicated results. Quick Checklist for Recruiters Must-Have: • Hands-on, comfortable designing AND building test setups, • Mechanical + electrical fundamentals (framing, pumps, heat exchangers, wiring), • CAD (SolidWorks preferred), • Python scripting (or similar), • Experience with NI DAQs, thermocouples, accelerometers, • GD&T knowledge/certification, • Familiarity with environmental chambers and liquid cooling, • Knowledge of power supply communication protocols (CAN, GPIB, SCPI, etc.), • Scrappy, ownership-driven, hands-on, • Comfortable balancing speed, safety, and standardization, • Thrives in a fast-paced, dynamic lab environment