Manufacturing Engineer – Advanced Composite Machining at Castelion in Torrance, CA

Job description

Why Castelion, Why Now Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability. This is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function. Manufacturing Engineer – Advanced Composite Machining About the Role We are seeking an experienced, hands-on CNC Machinist / Manufacturing Engineer specializing in 5-axis machining and advanced composite materials. This role combines advanced CAM programming, machine setup and operation, tooling strategy, and manufacturing process development. The ideal candidate will have extensive experience programming and operating 5-axis CNC machines using Siemens NX CAM and/or Mastercam , with direct experience machining advanced materials such as carbon-carbon, phenolic composites, and carbon-silicon carbide (C/SiC) . A major focus of this position is cutting tool selection and optimization . The successful candidate will understand how tool geometry, substrate, coating, cutting-edge preparation, toolpath strategy, feeds, speeds, and tool engagement affect machining quality, tool life, cycle time, and overall process capability. This individual will help develop robust machining processes for complex components, working closely with engineering, quality, and manufacturing teams to transition R&D hardware into repeatable production. Key Responsibilities 5-Axis CNC Programming & Machining Develop, program, simulate, and prove out complex 5-axis CNC machining operations. Create advanced CAM toolpaths using Siemens NX CAM and/or Mastercam. Optimize toolpaths for material removal, surface finish, dimensional accuracy, cycle time, and machine utilization. Generate, verify, and maintain CNC programs, post-processed code, setup sheets, and machining documentation. Set up and operate 5-axis CNC machines, including workholding, tooling, probing, and process verification. Troubleshoot toolpath, machining, vibration, surface quality, and dimensional issues. Apply appropriate strategies for complex geometries, thin sections, intricate features, and close-tolerance components. Cutting Tool Selection & Optimization — Primary Focus Select and validate cutting tools specifically suited to carbon-carbon, phenolic, C/SiC, and other advanced composite materials. Evaluate tool geometry, cutting-edge design, substrate, coatings, abrasive-wear resistance, and tool construction. Determine appropriate feeds, speeds, chip loads, stepovers, stepdowns, and tool engagement strategies for each material and operation. Evaluate diamond tooling, PCD tooling, carbide tooling, and other specialized cutting tools as appropriate to the material and application. Develop tooling strategies that minimize fiber pullout, delamination, edge breakout, chipping, thermal damage, and dimensional instability. Establish tool-life expectations, wear limits, replacement criteria, and tooling performance standards. Conduct tooling trials and document results to compare tool life, surface finish, dimensional accuracy, cycle time, and cost per part. Work directly with cutting tool suppliers to evaluate new tooling technologies, conduct trials, and resolve machining challenges. Standardize tooling selections and cutting parameters to improve process repeatability and reduce unnecessary tooling costs. Build a structured tooling database containing tool specifications, approved applications, cutting parameters, performance data, and lessons learned. Advanced Composite Machining Machine carbon-carbon, phenolic, and carbon-silicon carbide components using appropriate material-specific machining strategies. Develop processes for abrasive, brittle, and f