Project Overview
Cactus Labs is a U.S.-based aerospace technology company developing advanced UAV platforms. For one of its flight prototype projects, Cactus Labs required custom UAV components including engine and structural parts with complex geometries, lightweight structures, and demanding material requirements.
The project involved more than 70 components delivered in prototype batches, covering multiple aerospace-grade materials, including Inconel 625, Ti-6Al-4V, 316L stainless steel, Nitronic 60, and AL 7075-T6.
Due to the aggressive prototype schedule, Cactus Labs needed a manufacturing partner capable of not only producing parts according to drawings, but also providing engineering support to identify manufacturing risks and optimize designs before production.
FastPreci supported the project through DFM analysis, process planning, CNC machining, metal 3D printing, sheet metal forming, and laser welding, helping transform complex aerospace designs into manufacturable assemblies.
Manufacturing Challenges for UAV Components
1. Manufacturing Ultra-Thin Inconel 625 Components
One of the most challenging components was an Inconel 625 liner with a wall thickness of only 0.6 mm and a length of 1 m.
Inconel 625 provides excellent high-temperature and corrosion resistance, but its poor thermal conductivity and strong work-hardening characteristics make thin-wall machining extremely difficult.
Manufacturing the liner from solid material would introduce significant risks:
- Excessive cutting force could deform the thin wall during machining.
- Heat accumulation could affect dimensional stability.
- Maintaining roundness and surface quality would be challenging.
Metal additive manufacturing was also considered unsuitable for this structure due to potential thermal stress and deformation at such a thin wall thickness.
2. Complex Multi-Material Assembly with Thin-Wall Welding
The Tip Nozzle Assembly combined 316L and Nitronic 60, requiring both different material properties and precise interface control.
The original design required a 0.7 mm wall thickness 316L 3D printed component. However, this created manufacturing risks:
- Thin walls increased the possibility of incomplete printing or deformation.
- Post-processing and finishing became more difficult.
- Combining thin-wall 3D printing with precision mating surfaces created conflicting requirements.
In addition, laser welding different stainless-steel alloys required precise control of heat input to prevent distortion.
3. Integrating Multiple Manufacturing Processes
Several UAV components required a combination of different manufacturing methods.
For example, the Hot Mast Assembly integrated:
- Metal 3D printing for complex internal channels;
- Sheet metal forming for tubular sections;
- CNC machining for precision interfaces;
- Laser welding for final assembly.
The challenge was not only producing individual parts, but ensuring all processes worked together to achieve final assembly accuracy.
Engineering Solutions on UAV Components
1. DFM Optimization Through Part Separation
Instead of forcing each component to be manufactured as a single piece, FastPreci proposed a design-for-manufacturing approach: separating complex assemblies into sub-components and selecting the most suitable process for each section.
For the Inconel 625 liner:
- The main tube section was produced by sheet metal rolling to form the thin-wall cylindrical structure.
- Both ends were CNC machined from solid material to achieve precise interfaces and dimensional control.
- The sections were then joined through laser welding.
This approach avoided the deformation risks associated with thin-wall machining while maintaining the required geometry and performance.
2. Optimizing Thin-Wall 3D Printed Components
For the Tip Nozzle Assembly, FastPreci recommended redesigning the structure into separate components:
- Tip Nozzle Bend: manufactured by 316L metal 3D printing.
- Tip Nozzle Flange: CNC machined from Nitronic 60 bar stock for precision mating surfaces.
- Final assembly completed through laser welding.
The wall thickness was increased from 0.7 mm to 0.8 mm, with internal reinforcement added to improve printing stability without significantly increasing weight.
This adjustment reduced manufacturing risk while improving overall structural reliability.
3. Controlling Aerospace Welding Quality
For thin-wall and multi-material assemblies, welding distortion and heat-affected zones were critical concerns.
FastPreci applied:
- Laser welding optimized for thin-wall aerospace assemblies;
- Controlled welding parameters to minimize heat input;
- Argon shielding protection where required;
- Optimized welding sequences to reduce deformation.
The welding procedures were carried out following AWS D17.1 aerospace welding requirements, with controlled laser welding parameters to ensure joint quality and dimensional stability.
For assemblies with different wall thicknesses, welding sequences were optimized to balance heat distribution and reduce accumulated deformation.
4. Managing Surface Finish and Post-Processing Requirements
Some components required both additive manufacturing and precision finishing.
For example, 3D printed surfaces typically reached approximately Ra 6.4 in the as-built condition, while the customer required smoother internal surfaces.
FastPreci applied:
- Solution treatment;
- Stress relieving;
- Polishing;
to improve surface quality and stabilize dimensions before final inspection.
The mating holes were CNC machined to meet the required Ra 3.2 surface finish, with the final surface quality improved to approximately Ra 2.0.
Results
FastPreci successfully delivered more than 70 UAV components involving multiple aerospace materials and manufacturing processes.
Key achievements included:
- Developed manufacturable solutions for ultra-thin Inconel 625 components.
- Integrated CNC machining, metal 3D printing, sheet metal forming, and laser welding within one project.
- Supported the transition from complex prototype designs to practical manufacturing solutions.
- Continued cooperation with Cactus Labs through subsequent production batches.
The project demonstrated FastPreci’s ability to support aerospace prototype development where engineering collaboration and manufacturing flexibility are critical.
Customer Feedback
“The liner sheet metal tube came in a single length — finish and circularity are well within our needs. Thank you to your entire team for the rapid turnaround on these components. We’re one of 72 teams out of 480 applicants, working hard to get airborne in a few weeks. So excited!”
— Aaron LaFevers, Cactus Labs
Engineering Insights for Similar Aerospace Projects
For complex aerospace prototype projects, manufacturability should be considered early in the design process to reduce production risks, avoid unnecessary costs, and improve development efficiency.
Several practical lessons from this project include:
Hybrid Manufacturing Overcomes Single-Process Limitations
Complex aerospace components do not always need to be manufactured as a single piece. Separating assemblies into 3D-printed sections, sheet metal tubes, and CNC-machined interfaces allows each feature to be produced using the most suitable process, improving manufacturability, dimensional control, and overall project efficiency.
DFM Optimization for Thin-Wall Structures
For thin-wall aerospace components, small design adjustments can significantly reduce manufacturing risks. In this project, increasing the wall thickness from 0.7 mm to 0.8 mm and adding internal reinforcement improved metal additive manufacturing stability and reduced deformation risks during printing, post-processing, and subsequent assembly.
Surface Finish Control for Metal Additive Manufacturing
As-printed metal additive manufacturing surfaces typically require additional post-processing when internal fluid passages demand tighter roughness requirements. Heat treatment, stress relieving, polishing, and HIP can help improve material density, mechanical properties, surface quality, and dimensional consistency.
If your aerospace or UAV prototype involves thin-wall structures, complex materials, or multi-process manufacturing challenges, FastPreci’s engineering team can provide DFM feedback and manufacturing recommendations based on your drawings.
FAQ
1. Can one supplier handle CNC machining, metal 3D printing, sheet metal forming, and laser welding for aerospace prototypes?
Yes. Complex aerospace prototypes often require multiple manufacturing technologies. FastPreci integrates CNC machining, metal 3D printing, sheet metal forming, and laser welding to simplify supplier coordination and improve process consistency.
2. Why is thin-wall machining challenging for aerospace materials like Inconel 625?
Materials such as Inconel 625 have high strength, poor thermal conductivity, and strong work-hardening characteristics. When wall thickness becomes extremely thin, cutting forces and heat can easily cause deformation or dimensional instability.
3. Why separate an aerospace component into multiple parts instead of manufacturing it as one piece?
Part separation allows each section to use the most suitable manufacturing method. For example, thin tubular sections may benefit from sheet metal forming, while precision interfaces are better produced through CNC machining.
4. Can metal 3D printed parts achieve aerospace-level surface requirements?
Yes, but additional post-processing is often required. Heat treatment, stress relieving, polishing, and CNC machining can help achieve tighter dimensional control and improved surface finish.
5. What information should engineers provide when requesting aerospace prototype manufacturing support?
Providing 3D models, drawings, material requirements, tolerance requirements, surface finish requirements, and intended application conditions allows engineers to evaluate manufacturing risks and provide more accurate DFM recommendations.
