3D‑Printed Custom Fuel Injector Grippers: Boosting Pick‑and‑Place Efficiency

Headquartered in Wisconsin, STS Technical Group has spent nearly four decades partnering with manufacturers on staffing, technical design, and engineering solutions. With a workforce of over 250 professionals across the United States, the company has consistently evolved alongside manufacturing technology, delivering cutting‑edge services that meet the demands of modern production environments.

STS chooses Formlabs’ SLA 3‑D printing platform for its expansive material library, medical‑grade quality, and superior part finish—attributes that are critical when creating components that must endure rigorous manufacturing conditions.

Choosing the Right Production Method for Your Component

When developing a new part, the selection of a production process—casting, machining, or 3‑D printing—requires a careful assessment of design complexity, material performance, and cost. Below are the key advantages of SLA 3‑D printing for industrial parts:

• Sub‑25‑micron layer resolution delivers finer detail than traditional casting or machining.
• Lower material and tooling costs for highly intricate designs.
• Rapid lead times—days instead of weeks.
• No post‑machining required, eliminating the need for expensive equipment and skilled labor.
• Wide range of durable, lightweight resins and metal‑filled composites.
• Digital files can be saved, reused, and modified without maintaining physical inventory.
• Designs can incorporate built‑in features—such as screw holes or hex cavities—for easier installation.
• When impact forces are a concern, resin parts can fail gracefully, whereas metal parts may deform and remain in tolerance.
• Lower replacement costs and faster turnaround for wear parts.
• Finish can be painted or coated directly on the printed surface.
• Materials that are difficult to machine—due to melting, chipping, or cracking—can be printed safely.
• Reduced shipping weight translates to lower logistics costs.

While metal components generally offer higher strength, many applications can be satisfied by engineered resins, especially when the part’s geometry and performance requirements align with SLA capabilities. Consider the operating environment—temperature, humidity, corrosives—when selecting the material. Large‑format printers like the Form 3L enable the production of sizable parts without compromising resolution.

Designing and Printing Custom Fuel Injector Grippers

Pick‑and‑place operations demand grippers that can reliably handle delicate components, maintain consistent positioning, and withstand repeated cycles. The design of the gripper must account for:

• Material compatibility with the fuel injector (e.g., avoiding surface marring).
• Grip strength and contact area to distribute force evenly.
• Geometry of the injector—often cylindrical with complex features.
• Clearances and tolerances required for downstream processes.
• Ease of installation, including integrated hex cavities for fasteners.

Traditional pneumatic‑cylinder grippers typically feature a V‑shaped jaw that can concentrate force and lead to wear on both the gripper and the injector. They also lack the precision needed for fine positioning, often necessitating secondary alignment equipment.

STS overcame these limitations by leveraging 3‑D printing to create a fully encompassing, radially oriented gripper. The process began with a Creaform laser 3‑D scan of the fuel injector, captured with VX Elements modeling software. This scan provided an accurate, high‑resolution digital replica, eliminating manual measurements and enabling precise CAD modeling.

The initial prototype was printed on a Formlabs Form 3 SLA printer using Standard Black Resin to evaluate fit and function. The design proved the feasibility of a single‑build print for both halves of the gripper, showcasing the speed and flexibility of SLA manufacturing.

For production, STS switched to Rigid 4000 Resin, a glass‑filled polymer that offers exceptional stiffness, durability, and a high‑quality finish suitable for repeated use in a manufacturing environment.

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Results

The new grippers met all performance criteria:

• Increased surface area reduced peak pressure, minimizing injector damage and gripper wear.
• Radial motion allowed interior clearance, eliminating sharp edges and ensuring smooth release.
• Accurate geometry aligned the injector precisely, reducing the need for additional alignment fixtures.
• Lower gripping force translated to reduced pneumatic/hydraulic pressure requirements.
• Integrated hex cavities simplified assembly and maintenance.
• In‑process serialization (e.g., barcode embossing) eliminated post‑processing labeling steps.

These benefits collectively lowered cost, shortened lead times, and improved overall reliability compared to the legacy grippers.

Conclusion

The Formlabs Form 3 platform, combined with robust CAD workflows, demonstrates a powerful alternative to conventional manufacturing for custom tooling. 3‑D printed parts can match or exceed the durability of metal components while offering superior design flexibility, faster production, and lower total cost of ownership.

STS Technical Group is poised to continue delivering highly detailed, custom solutions—leveraging 3‑D printing to meet the evolving needs of automated manufacturing.

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