Principal Mechanical Design Engineer (Hardware & Hydraulics)

Job description:

Website

https://tetherusa.com

Pay

Minimum: $65,000 Profit Based Bonus Share. Base rate depends on experience.

The Mission

Tether is navigating an aggressive, high-stakes roadmap. We are actively executing Department of War (DoW) obligations on the USMC ROGUE platform while simultaneously laying the groundwork for a commercial autonomous trucking pilot. We are transitioning from early-stage R&D to aggressive commercial deployment, which requires a profound departure from traditional academic engineering. We operate with high intensity, minimize corporate bureaucracy, and give our small teams massive autonomy to execute.

Role Overview

We are seeking an elite Principal Mechanical Design Engineer to serve as the chief physical architect of our systems. You will lead the ground-up mechanical design of our next-generation "Tether"—a highly complex, electro-hydraulic system—as well as the structural, pneumatic, and compute-packaging systems that integrate directly into Class 8 commercial and military trucks.

You must possess an exceptionally deep understanding of hydraulics, machining, advanced materials science, and Design for Manufacturability (DFM). You will not just sit behind CAD; you will oversee fabrication, turn wrenches to test assembly/serviceability, and ensure every physical component survives the extreme shock, vibration, and thermal environments of off-road military and heavy-duty trucking operations.

Immediate Engineering Portfolios (What You Will Build First)

• Hydraulic System Architecture (The Next-Gen Tether): Lead the mechanical design of our next-generation "Tether" system—a highly custom hydraulic cylinder acting as the primary physical link between vehicles. You will integrate internal flow control manifolds, valves, and sensors into a precision-bored 6ft tubing/housing.
• Pneumatic & Safety-Critical Design (Electronic Air Brake Control Unit - EABCU): Architect a custom, safety-critical pneumatic manifold housing. You will combine OEM air pressure control valves, solenoids, check valves, pressure sensors, and embedded custom PCBs into a highly robust unit designed for the engine bay of Class 8 vocational trucks.
• Heavy-Duty Structural Integration: Design a highly custom, lightweight bumper system and specialized hitching hardware capable of safely handling the massive dynamic loads of a fully loaded semi-truck trailer. Modify existing commercial truck trailers to safely and smoothly accept connection with the Tether.
• Thermal & Vibration Mitigation (Ruggedized Compute Capsules): Design the main compute housing (containing controllers, data loggers, power management, and custom PCBs). You will solve complex electrical routing, thermal and vibration management challenges for both off-road military and on-highway environments.
• Packaging & Enclosures: Design and validate robust HMI mounting solutions, highly durable weatherproof ECU enclosures, and complex packaging architectures that bridge the gap between our physical hardware and embedded electronics.
• End-to-End Ownership: Manage the entire lifecycle of physical parts from initial CAD to final assembly. You will source materials, audit manufacturing partners, and assemble initial prototypes to validate Design for Manufacturability (DFM) and serviceability.

Requirements, Technical Mastery & Cultural Fit

• Fluid Power (Hydraulics & Pneumatics): Elite-level understanding of hydraulic and air systems. You must deeply understand sealing technologies (O-rings, lip seals, cup seals, backup rings) and high-pressure fitting standards (ORB, NPT, ORFS).
• FEA & Structural Kinematics: Proven ability to run complex Finite Element Analysis (FEA) to simulate dynamic load stresses, fatigue, and shear limits. You will be designing structural hitches and bumpers that must withstand the massive dynamic loads of fully loaded Class 8 trucks.
• Extreme Tolerance Machining: Experience designing for precision manufacturing, including deep-hole/line boring operations (e.g., maintaining /- 0.001" straightness over 6ft spans).
• Materials & Surface Science: Deep knowledge of ferrous and non-ferrous materials, specifically aluminum treatments (hardening, anodizing), and protective coatings (powder coating, epoxy, oxide coatings, liquid paint) for severe corrosion resistance.
• Environmental & Ruggedization Standards: Deep familiarity with designing for extreme environments, ensuring systems meet stringent standards like MIL-STD-810 (shock and vibration) and heavy-duty IP-ratings (ingress protection) for all ECU and compute enclosures.
• Advanced Manufacturing & DFM: Fluent in designing for specific manufacturing processes including sheet metal bending, plate profiling, casting, extrusion, additive manufacturing, and varied welding processes (MIG, TIG, Stick, Friction).
• Vendor Auditing & Quality Control: Proven capability to technically evaluate and audit external machine shops, foundries, and raw material suppliers. You will be ordering plate, sheet metal, and extrusions, and must ensure external vendors meet our strict engineering tolerances.
• Electro-Mechanical & Automotive Intuition: Strong baseline understanding of heavy-duty automotive topologies and low-voltage electrical systems. You must know how to package PCBs safely within extreme environments.
• Execution & Prototyping: A strict "no task is beneath me" mentality. We do not want theoretical CAD jockeys who refuse to touch the hardware. You will physically assemble prototypes, validate assembly flow (DFA), turn wrenches, get dirty on the shop floor, and take extreme pride in physically manifesting your designs.
• Adaptability: The transition from defense R&D to commercial freight is chaotic and high-speed. You must thrive in an environment of rapid iteration where physical requirements can shift. You must be highly capable of reverse-engineering existing mechanical hardware, adapting to complex physical challenges on the fly, and taking absolute ownership rapidly.
• Software: SolidWorks is our preferred CAD environment, but we care entirely about output and results, not the specific tool you use.

Compensation & Benefits

To attract the "A-Team," we offer an aggressive, upside-driven compensation model and unparalleled operational freedom:

• Profit-Sharing: We execute a highly lucrative Profits Based Bonus Share Plan calculated from 15% of the company's Earnings Before Taxes (EBT), directly linking your technical execution to your financial upside.
• Healthcare: Employer-sponsored health insurance.
• Retirement & Savings: 401k matching and direct Employer Health Savings Account (HSA) contributions.
• Ultimate Flexibility: Three full weeks (15 days) of Paid Time Off (PTO) with no officially mandated corporate holidays, trusting you to manage your output and recovery like a high-value operator.

Benefits

• 401(k) matching
• Health insurance
• Health savings account
• Paid time off

Work Location: In person