Prototype Machinist

Therm-x of California is the leading manufacture for Advanced Temperature and Control Systems for Hi-Technology industries. We have been in business for over 30 years and have a diverse customer base. We offer competitive pay, medical, dental, 401 (K), and paid time off.

The Prototype Machinist / NPI Technician works alongside Therm-x's NPI Engineering team to bring new heater, sensor, source, and cathode designs from drawing to first working part. Our prototyping cell is built around a 5-axis Okuma mill and a CNC lathe, and it runs separately from the production shop — giving this role the time and autonomy to make new parts the right way the first time.

Because most prototypes are one-off, complex geometries, this is fundamentally a 5-axis and CAM-programming role. The job is reading a fresh drawing, programming the toolpath, choosing the right way to hold and cut the part, talking with the design engineer about a tolerance that does not make sense, and shipping a clean first article. The same part is rarely run twice. When the cell is not loaded, this role also supports the NPI team with fixture builds, test setups, and general shop-floor work.

Responsibilities include, but are not limited to; 

• Program, set up, and operate the 5-axis Okuma mill (and CNC lathe) to produce prototype parts, tools, and fixtures.


• Generate efficient CAM programs (Mastercam, HSM, Esprit, NX CAM, or equivalent) from 3D models, including multi-sided and simultaneous 5-axis toolpaths.


• Verify toolpaths in simulation before cutting; catch collisions, gouges, and reach issues at the CAM stage, not at the spindle.


• Select cutting tools, feeds, speeds, and toolpath strategies appropriate for each prototype material and geometry.


• Choose appropriate workholding — vises, soft jaws, clamps, custom fixtures, 5-axis tombstones, and risers — for one-off and low-quantity parts.


• Read and interpret engineering drawings with GD&T; confirm critical dimensions and surface finishes.


• Inspect parts using calipers, micrometers, height gauges, and other standard inspection tools; record results for First Article Inspection (FAI).


• Collaborate directly with mechanical engineers — flag drawing or manufacturability issues early, including DFM input on parts that should be redesigned for 5-axis efficiency.


• Build basic test fixtures and assist NPI engineers with prototype assembly, instrumentation, and data collection.


• Maintain a clean, organized, and safe prototyping cell; track tooling, consumables, and machine condition.


• Help evaluate new tools, processes, and machines as the prototyping cell evolves.


• Support NPI technician work outside the cell as needed: test setups, basic data collection, and general shop-floor support.

Desired Skills 

• Hands-on 5-axis CNC milling experience — programming, set-up, and operation. Okuma (OSP control) strongly preferred; equivalent 5-axis platforms (DMG MORI, Mazak, Matsuura, Haas UMC) considered.


• Strong CAM programming skills — Mastercam, HSM, Esprit, NX CAM, or equivalent — including multi-sided and simultaneous 5-axis toolpaths, with the ability to verify and post-process programs reliably.


• Solid grounding in milling principles: cutter selection, feeds and speeds, and how material, tooling, and fixture choices affect part quality on multi-axis work.


• Comfort reading drawings with GD&T and interpreting tolerances correctly.


• Confident use of standard inspection tools: calipers, micrometers, indicators, height gauges.


• Computer literacy — opening files, viewing 3D models, running CAM simulations and machine simulations to catch collisions before cutting.


• Strong written and verbal communication; able to talk through a drawing with an engineer, not just run parts.


• Hands-on, safety-first work habits in an active shop environment.

Strong Plus

• Direct experience on Okuma machines and OSP control.


• CNC lathe and mill-turn experience.


• Basic 3D modeling (SolidWorks, Inventor, Fusion 360) and the ability to design simple fixtures.


• Probing and in-process measurement on multi-axis machines.


• Prior NPI or prototype experience, or a job-shop background with frequent setup changes.

Physical Demands: While performing the duties of this Job, the employee is regularly required to stand; walk; sit; use hands to finger, handle, or feel; reach with hands and arms; climb or balance; stoop, kneel, crouch, or crawl; talk or hear and taste or smell. The employee must occasionally lift and/or move up to 50 pounds.

Work Environment: high noise level associated with manufacturing facility