As launch schedules tighten, aerospace fabricators face a glaring operational bottleneck: forming curved rocket body panels with complex machined grid patterns.
Historically, achieving these curved cylindrical or conical shapes took up to 60 hours per panel using conventional press brake bump forming. Today, advanced heavy-duty plate rolling technology from Davi reduces that forming cycle to under 60 minutes while preserving intricate structural geometries.
The Challenge: Bending Variable-Thickness Structural Grids
To withstand the severe physical stresses of launch while minimizing weight, roughly 80% of aerospace manufacturers utilize isogrid (triangular) patterns, while others rely on orthogrid (rectangular) patterns.
Machining these structural grids creates drastic thickness variations across a single aluminum panel. Panel thicknesses typically range from 6.35 mm (0.25 inches) up to 76.2 mm (3.0 inches). Once pocketed, delicate vertical ribs are left standing while adjacent pocket sections are machined down to half their original material thickness. Furthermore, components often feature varying rib heights, irregular cutouts, and grid patterns machined on either the outside diameter (OD) or inside diameter (ID).
Forming these non-uniform structures introduces severe fabrication risks:
- Rib Crush Risk: Standard pinch pressures can easily crush or deform delicate structural ribs.
- Irregular Rolling Contact: Because the plate back is flat while the opposite side consists of localized ribs, the rolling machine contacts only the highest points of the grid.
- Capacity Calculation Complexity: Machine capacity cannot be calculated using standard full-width plate dimensions. Instead, bending torque and structural resistance must be calculated using the equivalent aggregate width of the tallest ribs alone.
Bump Forming vs. Plate Rolling: The Operational Impact
For years, aerospace fabricators relied on step bending or bump forming on press brakes. While functional, the process is inherently labor-intensive and slow.
| Operational Criteria | Press Brake Bump Forming | Davi Heavy-Duty Plate Rolling |
| Forming Cycle Time | Up to 60 hours per panel | Less than 1 hour per panel |
| Material Handling | Continuous overhead crane support required | Automated, self-contained loading and rolling |
| Surface Finish | Faceted polygon micro-flats requiring manual checking | Smooth, continuous radii without micro-facets |
| Repeatability | Highly dependent on operator skill | High-volume consistency via CNC automation |
Engineered Rolling Strategies for Machined Aerostructures
To roll machined grid panels without compromising geometric integrity or structural strength, Davi applies three distinct engineering approaches based on panel design and production volume:
- Filler Material Integration: Temporary sacrificial material or edge inserts are placed within machined pockets to balance overall thickness, allowing standard pinch pressure application across uniform heights.
- Advanced Process Control & Custom Tooling: Skilled operators utilize proprietary rolling parameters, leveraging machine systems like the Davi MAV 3-Roll Variable Axis or MCB 4-Roll series to precise tangent points without crushing delicate rib lines.
- Custom Profiled Rolls: For high-volume production lines where machined grids cover only a portion of the panel (e.g., 70% grid coverage, 30% solid margin), Davi engineers custom stepped or profiled rolls. The varying roll diameters match the geometry of the panel perfectly, ensuring continuous contact pressure across both raw plate and machined sections.
Driving Precision with Davi Bending Technology
Handling complex, high-value aerospace alloys requires rigid machine architecture and precise control systems:
- Torque Distribution & Grip: Machines like the Davi MAV feature independent motorized drives on all rolls, ensuring synchronized torque transmission without plate slippage during critical pre-bending phases.
- Parallelism Control: Davi’s patented Servo-Tronic system maintains continuous hydraulic and mechanical roll parallelism, eliminating dimensional twisting on delicate aerospace panels.
- Digital Process Monitoring: Integrating advanced controls like iRoll eXtreme with AI-Vision technology allows manufacturers to measure surface radii in real time, automatically compensating for material springback without manual template checks or destructive trial-and-error runs.
By transitioning from legacy bump forming to engineered plate rolling solutions, aerospace manufacturers eliminate severe production bottlenecks, lower labor overhead, and scale panel output to meet modern launch demands.