CNC Machining Case Study: Industrial UAV Components

From a Google Ad to a Flight-Tested Frame

The Connection: Finding a Reliable Partner

The client first encountered KH Precision while researching high-end manufacturing partners via LinkedIn and specialised Google Search queries. After being targeted by a Google Ads campaign specifically highlighting our thin-wall machining capabilities, their engineering lead reached out.

Despite the geographical distance, they decided to approach us with a “test batch” mindset — initially sceptical, but looking for a shop that could actually hold the specs.

Project Background: The “Weight vs. Stiffness” Dilemma

The project involved the Gen-3 “Atlas” heavy-lift drone. Previous iterations suffered from harmonic vibration during high-speed flight, which interfered with the LIDAR sensor accuracy. The structural frame needed to be light enough for a 45-minute flight time, but stiff enough to withstand the torque of high-KV industrial motors.

Our Immediate Response & Technical Roadmap

Upon receiving the 3D STEP files, our engineering team did not just generate a quote. We performed a Design for Manufacturing (DFM) review and identified that the 1.8 mm thin-wall arm sections would likely warp if machined with standard clamping.

Our strategy:

• Stress Management: we proposed a staged material removal process — roughing, followed by a 24-hour stress-relief cycle, before the final finish pass.
• Custom Fixturing: we engineered dedicated vacuum chucks to distribute clamping pressure evenly, preventing the “spring-back” effect common in aerospace-grade 7075-T6.
• 5-Axis Logic: to maintain the angular relationship between the motor mount and the main chassis, we determined the part must be finished in a single setup on our Haas UMC-750.

Project Challenges & Value-Added Cost Reduction

The primary challenge was the internal pocketing of the gimbal housing, which featured complex compound curves. To help the client scale without exhausting their R&D budget, we suggested a Hybrid Processing approach. By changing non-critical internal fillets from R0.5 to R1.5, we allowed larger diameter cutters to run at higher feed rates, reducing machining time (and cost) by 18% without impacting the structural integrity or weight.

From CAM Programming to Final Inspection

Our CNC programmers utilised Mastercam to develop high-speed trochoidal milling paths, minimising heat transfer to the workpiece.

• Timeline: first articles were completed in 5 days; the full batch of 20 sets was shipped within 12 working days.
• Quality Assurance: every critical datum was verified using a Hexagon CMM. We provided a full dimensional report (FAI) and material mill certificates (Cert 3.1) for every component.
• The Result: the client reported a 30% reduction in vibration resonance during their first flight test compared to their previous prototype.

Forward-Thinking: A Proposed Gen-4 Optimization

Based on our experience with this delivery, we have already provided the client with a “Phase 2” proposal for their next production run.

Instead of traditional 7075-T6 for the motor mounts, we are testing a Metal Matrix Composite (MMC) or potentially a Topological Optimization (generative design) approach. By utilising 3D-printed titanium inserts for the high-stress mounting points combined with carbon fibre over-moulding, we believe we can shave another 12% off the structural weight while further increasing the damping coefficient — solving vibration issues at the source rather than through software.