FANUC SCARA robot on an automated machine with an SDC Indexing Ring

Circuit Breaker Assembly Machine

Project Scope: Building an Automated Circuit Breaker Assembly Machine

A manufacturer of electrical protection devices partnered with SDC to build a fully automated circuit breaker assembly machine. The customer needed to assemble several small parts, including a base and circuit board, an armature, and a current path assembly, into one finished part. Doing this by hand was slow and made it hard to keep quality consistent from part to part. SDC needed to design a machine that could handle nearly every step, from parts feeding through final inspection, at high speed with minimal operator involvement.

Technology Used

SDC Indexing Ring
Three FANUC SCARA robots
SDC servo-driven pick-and-place units
Three SDC Tray Handlers
Keyence vision systems for multi-stage in-process inspection
Three Bellco vibratory bowl feeders — one large and two small with noise reduction
Station for preforming and routing of a small, stranded wire assembly before installation
Servo-driven transfer system for moving the stranded wire assembly to an insertion mechanism at the main indexing ring

The Machine Concept:

SDC’s concept centered on building the machine around a single servo-driven SDC Indexing Ring, one of SDC’s pre-engineered technology platforms. This ring handled the full main assembly sequence, from base and circuit board loading through final inspection. A dedicated SDC Tray Handler and FANUC SCARA robot brought in the current path assembly (CPA), a pre-made stranded wire assembly produced on separate equipment and delivered in custom trays. A vision system located each CPA in the tray stacker, and a dynamic tooling fixture positioned both ends of the part before it was fed onto the ring at the right point in the cycle.

This approach let SDC apply proven, pre-engineered technology to a project with many unique part-handling challenges. Instead of building an entirely custom system, SDC adapted its existing indexing ring, tray handling, and pick-and-place designs to fit this application. As a result, engineering risk dropped, and the machine reached production faster.

Solution:

SDC built the machine around a single 30-position servo-driven SDC Indexing Ring, one of SDC’s pre-engineered technology platforms. A FANUC SCARA robot and SDC Tray Handler destacked trays of base and circuit board subassemblies and loaded them into the ring’s fixtures. As the ring indexed forward, SDC pick-and-place units installed a mid base and several more components. Vertical probes after each insertion operation checked that each part was fully seated.

Meanwhile, a second SDC Tray Handler processed 40 custom trays built to work alongside the customer’s own plastic trays of 28 assemblies each. A vision system identified each CPA’s location and orientation in the tray stacker, and a second FANUC SCARA robot, fitted with a multi-gripper end-of-arm tool, picked the assembly and transferred it to a dynamic tooling fixture that positioned both ends of the part.

From there, a servo-driven transfer system carried the positioned CPA into the main indexing ring, where an SDC pick-and-place installed it into the base assembly. A vision system inspected the assembly at this point, flagging any part that did not meet requirements before it moved on.

A third FANUC SCARA robot and SDC Tray Handler then unloaded finished assemblies. Good assemblies were placed onto a finished parts tray, while rejected parts were routed to a separate reject station for review.

Results & Business Impact:

The finished system was designed to run at a 3-second cycle time, with a target of 2.8 seconds as tooling and programming were optimized. As a result, the customer gained a reliable, repeatable production rate for a part that previously required careful manual assembly.

  • Cycle time of 3 seconds per part, with a 2.8-second target
  • Multiple in-process vision inspections to catch defects before final assembly
  • Reduced manual handling through automated tray loading and unloading
  • Machine designed to run two product variations with minimal changeover
  • Compact footprint of about 40 feet by 20 feet for the complete system

Operational Workflow:

  1. Load Base and Circuit Board: A FANUC SCARA robot and SDC Tray Handler destack trays and place each base and circuit board subassembly into a fixture on the indexing ring.
  2. Install Housing: An SDC pick-and-place installs a housing fed by a large Bellco vibratory bowl feeder, and a horizontal probe confirms it is fully seated.
  3. Install Armature: A second SDC pick-and-place installs an armature fed by a small Bellco vibratory bowl feeder, again verified by a horizontal probe.
  4. Locate and Unload CPA: A second SDC Tray Handler processes custom trays of CPAs alongside the customer’s own trays, while a vision system locates each part in the tray stacker.
  5. Pick and Position CPA: A second FANUC SCARA robot with a multi-gripper end-of-arm tool picks the CPA and transfers it to a dynamic tooling fixture that positions both ends of the part.
  6. Transfer and Install CPA: A servo-driven transfer system carries the CPA to the indexing ring, where an SDC pick-and-place installs it into the base assembly.
  7. Install Blade Holder: An SDC pick-and-place installs a blade holder into the assembly.
  8. Final Inspection and Unload: A vision system inspects the completed part; a third FANUC SCARA robot and SDC Tray Handler unload good assemblies onto a finished parts tray, and rejects are routed to a separate station.

SDC Standard Products: Eliminating Engineering Risk with Proven Solutions

SDC Indexing Ring

This project relied on the SDC Indexing Ring, one of SDC’s proven, pre-engineered technology platforms. Its open-ring design lets SDC place workstation modules exactly where the process needed them, giving the main assembly a reliable, repeatable foundation. Because the platform was already engineered and tested, SDC applied it to this project with less risk and a faster path to production.

SDC Indexing Ring 3D rendering

Key Features:
  • Servo-Driven with Shot Pin Engagement: Delivers smooth, precise, repeatable positioning with secure locking at each station.
  • Advanced PLC Control System: Provides intelligent automation and real-time monitoring for optimized performance.
  • SDC Custom Tooling: Tooling built to meet this project’s specific part-handling needs.
  • Sealed Indexer Gearbox: Protects internal components from contamination for long-lasting, low-maintenance performance.

SDC Tray Handling

SDC also used its SDC Tray Handling system to manage part trays throughout the process. This pre-engineered platform automated tray loading and unloading at three points in the machine, cutting down on manual material handling. As a result, operators could focus on other tasks instead of restocking trays by hand.

A Steven Douglas Corp (SDC) robotic packaging machine encloses a series of cardboard boxes in a metal frame with clear plastic sides.

Key Features:
  • Vision System and Robotic Integration: Works with vision systems and robots for precise loading, unloading, and quality control.
  • Content and Position Verification: Vision and sensors track tray content and position to reduce errors.
  • Escapement-Controlled Movement: Ensures smooth transitions and precise spacing between trays, reducing jamming.
  • Flexible Configurations: Available as a single unit or a compact double configuration to fit different layouts.

Conclusion:

Overall, this project shows how SDC applies proven, pre-engineered technology to solve complex assembly challenges. By combining the SDC Indexing Ring, SDC Tray Handling, robotics, and vision inspection, SDC gave this manufacturer a reliable, high-speed way to assemble a multi-part product. The design addressed the customer’s need for consistent quality without relying on manual assembly. It also built in the flexibility to run more than one product variation on the same machine. This kind of ring-based architecture is a strong example of how SDC’s standard technology can be adapted to fit unique customer requirements. In the end, the result is a machine that reduces engineering risk while still meeting each customer’s specific production needs.

FAQs (Frequently Asked Questions)

Q: What is a circuit breaker assembly machine?

A: A circuit breaker assembly machine is automated equipment that builds a circuit breaker’s internal parts into one finished unit. These parts include the base, housing, armature, blade holder, and current path assembly. The machine replaces manual assembly steps with robots, feeders, and automated inspection.

Q: How fast can this machine run?

A: The machine was designed for a 3-second cycle time, with a target of 2.8 seconds per part once fully optimized. That means it can complete one finished assembly roughly every 3 seconds.

Q: What technology does SDC use in this type of machine?

A: SDC used the SDC Indexing Ring, a pre-engineered technology platform, to run the main assembly. It also added SDC pick-and-place units, three FANUC SCARA robots, and three SDC Tray Handlers. Two Bellco vibratory bowl feeders, a preforming station, and vision inspection systems rounded out the technology, helping load, orient, and assemble the parts.

Q: How does the machine ensure quality?

A: The machine uses vision inspection systems at multiple stages of the process. Each assembly is checked before moving to the next step, so problems are caught early and rejected parts are automatically routed away from good ones.

Q: Can this machine handle more than one product variation?

A: Yes. The machine was designed to run more than one product variation with minimal changeover, so the customer can switch between parts without major downtime.

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