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Mechanical Engineer

Fermilab · Batavia, IL · $99,500–$130,900 a year · Full time

Posted Sep 13, 2026 · We last checked this listing on Oct 6, 2026

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Likely interview questions for this role

Written from this job description, not a generic list. Each one notes what the interviewer is really checking.

About your past

Tell me about a mechanical system you designed, fabricated, tested and installed. Where did it go wrong and how did you fix it?

What they are checking: Whether they have taken real hardware through the full lifecycle, which this role spans.

Tell me about a time you oversaw drafters or technicians. How did you make sure the work was right?

What they are checking: Whether they can lead and check others' work, since the role oversees designers and technicians.

Tell me about a new tool or technology you brought into your engineering work.

What they are checking: Whether they actively seek better methods, which the posting says it wants.

What would you do

As Primary Machine Engineer for the Main Injector and Recycler, how would you get up to speed on the mechanical systems in your first few months?

What they are checking: Whether they have a practical plan for learning a large existing accelerator and its history quickly.

How do you plan an installation or repair that has to fit inside a short accelerator shutdown?

What they are checking: Whether they can plan tightly, stage parts and coordinate crews so work fits a fixed maintenance window.

How do you work with physicists who want a design change late in a project?

What they are checking: Whether they can weigh scientific needs against cost, schedule and safety and negotiate a sound answer.

How would you divide your time between running MI/RR and supporting PIP-II and LBNF design work?

What they are checking: Whether they can juggle operations support with future project work without letting either slip.

About the work

What analysis would you run on a support structure for a heavy magnet in an accelerator tunnel?

What they are checking: Whether they apply stress, deflection, alignment and seismic considerations with sound engineering judgment.

What do you consider when designing components for a radiation environment or ultra-high vacuum?

What they are checking: Whether they know material and design constraints specific to accelerator components.

How do you document an upgrade so that the next engineer understands what was installed and why?

What they are checking: Whether they keep drawings, travelers and records current, which matters on decades-old machines.

What CAD and analysis tools do you use, and how do you check your results?

What they are checking: Whether they validate simulations with hand calculations and judgment rather than trusting software blindly.

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The full job description

As published by Fermilab.

The expected hiring range for this position is: $99,500.00-$130,900.00. Please note that the pay range information is a general guideline only. The pay offered to a selected candidate will be determined based on factors such the scope and responsibilities of the position, qualifications of the selected candidate, business considerations, internal equity, and external market pay for comparable jobs. This position is not eligible for sponsorship assistance. About the Role: We are seeking a Mechanical Engineer to become the Main Injector/Recycler (MI/RR) Primary Machine Engineer who is a collaborator by nature and who seeks out the latest technology and tools to design, fabricate, test, install and operate components and systems for our particle accelerators. What your day-to-day as a Mechanical Engineer at Fermilab will look like: • You will serve as Primary Machine Engineer for the MI/RR machines and work with MI/RR machine stakeholders and scientists in the planning, implementation, and documentation of the installation of upgrades and repairs to the mechanical systems that support this accelerator. Oversee engineers, drafter/designers and technicians in their tasks. • Provide support to future accelerators such as PIP-II and LBNF in the mechanical design, analysis, fabrication/construction, and installation of devices and equipment. • Utilize fundamental engineering concepts and principles to complete assignments and develop familiarization with the Laboratory’s method of project engineering, from the design stage through review, procurement, fabrication, installation, test and operation. • Participate in and leading efforts involving general mechanical-system design, mechanical stress analysis, and thermal analysis. • Designing and planning the lifting/rigging of heavy components which will involve material handling equipment and techniques. • Overseeing and directing the activities of early-career engineers, technicians, and drafters/designers on their projects. • Direct the activities of co-op engineering students and interns on his/her projects. • Abide by and be responsible for performing all duties in accordance with all environmental, health and safety regulations and practices pertinent to this position. Skills and Attributes for Success: • Bachelor’s in an applicable Engineering discipline from an ABET accredited institution with 6+ years of engineering experience, or a Master’s in an applicable Engineering discipline from an ABET accredited institution with 4+ years of engineering experience. • Demonstrated ability to communicate expectations clearly using verbal and written practices with customers / stakeholders and with team members • Demonstrated ability to lead a team in a project (technical or non-technical) and installation activities • Demonstrated ability to work effectively under the requirements of schedules and shifting priorities • Demonstrated ability to perform mechanical stress and deflection calculations • Demonstrated ability to create and read mechanical drawings • Demonstrated knowledge of machine shop practices and techniques for fabricating complex and intricate hardware • Must have strong computing skills including preparing and documenting engineering calculations, creating 3D models and 2D drawings using CAD software, FEA analyses, data presentation, and project management activities (cost estimates, schedules) • Experience with design, assembly and operation of high and ultra-high vacuum systems is desirable • Knowledge of welding and brazing practices (e.g. TIG, MIG and electron beam welding process, oven brazing) as related to manufacturing and fabrication of structures is desirable • Knowledge of materials, metallurgy and radiation damage of materials is desirable • Knowledge in the design and planning of lifting/rigging of heavy components which involve material handling of equipment and techniques is desirable • Use of geometric dimensioning and tolerancing on drawings is desirable • Planning and implementing preventative maintenance programs for a system’s equipment is desirable • Skills in Siemens Teamcenter and NX is desirable • Skills in ANSYS or NASTRAN is desirable • Experience in specifying, designing, fabrication, and operations of robotics systems is desirable Physical Activity and Work Conditions • HUMAN FACTORS: Heights, mental concentration, sitting, standing, tight work schedule, visually demanding. Work Arrangement: Please note that the described work arrangement is subject to change based on business needs and is not guaranteed to be final. • Onsite : This is an onsite role, and the candidate must be able to work from our Batavia office. Benefits/Perks: Fermilab offers a competitive and comprehensive benefits program, including: • Medical, Dental, Vision and Flexible Spending Accounts • Paid time off • Life insurance • Short and Long-term disability insurance • Retirement benefits • Onsite day care Why Fermilab: Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. We support discovery science experiments in Illinois and locations around the world, including deep underground mines in South Dakota and Canada, mountaintops in Arizona and Chile, CERN in Europe and the South Pole. Pre-Employment Screening: Drug-Free Workplace & Pre-Employment Screening Fermilab is dedicated to fostering a safe, productive and drug-free environment. An offer of employment is contingent upon the successful completion of a background check and drug screening. HSPD-12 In accordance with Homeland Security Presidential Directive 12 (HSPD-12) new employees are required to obtain and maintain a HSPD-12 Personal Identity Verification (PIV) Credential. To obtain this credential, new employees must successfully complete and pass a federal background check investigation. This investigation includes a declaration of illegal drug activities, including use, supply, possession, or manufacture. This includes marijuana and cannabis derivatives, which are still considered illegal under federal law, regardless of state laws. Failure to obtain or maintain such government access authorization could result in the withdrawal of a job offer or future termination of employment. Foreign Government Sponsored Activities Fermilab employees, and certain guest researchers and contractors, are subject to particular restrictions related to participation in Foreign Government Sponsored or Affiliated Activities, as defined and detailed in United States Department of Energy Order 486.1A. Such individuals will be asked to disclose any participation for review by Fermilab's Office of General Counsel. REAL-ID Requirement for access to Fermilab Campus Fermilab requires all members of the public to produce a REAL-ID, or equivalent, to access the Fermilab Campus for interviews or career events. A list of acceptable forms of ID can be found here: https://get-connected.fnal.gov/wp-content/uploads/2021/09/REALID-Documents.pdf . If a candidate is selected for an interview but does not possess any of the equivalent documents, we may schedule a virtual interview. Equal Opportunity Statement Fermilab is an equal opportunity employer. We evaluate qualified applicants without regard to race, color, religion, sex, age, national origin, disability, veteran status, genetic information, and other legally protected categories.

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