Epoxy Segment (Motor Grade)

High-Bond Surface, Electrical Insulator, Marine-Grade Corrosion Resistance We supply Custom Neodymium Arc (Segment) Magnets encapsulated in a premium Black Epoxy Coating. Standard Nickel plating is common for general magnets. But it is often a poor choice for high-performance electric motors. Our Epoxy coating aims to solve the three biggest challenges in motor design: – Rotor Adhesion, Eddy Current Losses, and Environmental Corrosion. As shown in the product photo, these segments feature a smooth, defect-free black finish with rounded edges. They are ready for immediate bonding onto steel rotors or stators. Why Epoxy for Segments? If you are building a motor, generator, or magnetic coupling, Epoxy offers functional advantages that Nickel cannot match. 1. The “Adhesion” Champion (Rotor Bonding): The Problem: Nickel plating is ultra-smooth and chemically passive. When gluing magnets to a steel rotor spinning at high RPM, Nickel bonds often fail. And they lead to catastrophic motor damage. The Epoxy Solution: Epoxy coating is resin-based. It possesses high surface energy and a microscopic texture. It bonds aggressively with industrial structural adhesives (Loctite, Araldite, 3M). It essentially acts as a primer. Ensure your magnets stay glued under high centrifugal force. 2. Electrical Insulation (Eddy Current Reduction): The Physics: Nickel is a metal; it conducts electricity. In high-speed motors, the changing magnetic fields induce “Eddy Currents” in the conductive plating. Generate heat and reducing efficiency. The Epoxy Solution: Epoxy is an electrical insulator. It breaks the circuit on the surface of the magnet. Prevents coating-based eddy currents. This helps keep your motor running cooler and more efficiently. 3. Superior Corrosion Barrier: The Benefit: Motors often operate in damp or outdoor environments (e.g., pumps, drones, marine outboards). Epoxy offers 200 – 500 Hours of Salt Spray Resistance. Far outperforming standard Nickel in high-humidity conditions. Manufacturing Specs: The “Soft Edge” Epoxy behaves like paint, not like metal plating. The geometry must be adapted. 1. Corner Radiusing (Tumbling): Observation: Notice in the product photo that the edges of the segments are not sharp. They are visibly rounded. The Reason: Liquid Epoxy pulls away from sharp 90° corners. Due to surface tension (the “edge-thinning effect”). Our Standard: We apply a heavy mechanical tumble to all segments before coating. This creates a Generous Radius (R). Ensures the epoxy wraps perfectly around the corners for a hermetic seal. 2. Thickness & Tolerance: The Spec: Epoxy is thick (20 – 30 microns). The Advice: When calculating your motor’s “Air Gap”, you must account for this extra coating thickness. Air gap means the space between the magnet and the stator coils. Do not design a zero-tolerance air gap. Ideal Applications Brushless DC (BLDC) Motors: Rotors for drones, power tools, and robotics. Marine Generators: Magnets exposed to salt air and condensation. Automotive Pumps: Fluid pumps where the magnet must resist oxidation. Magnetic Couplings: Torque transfer devices requiring glue stability. Ordering Guide: Precision Arcs To manufacture custom segments, we need the “4 Numbers”: 1). Dimensions: – OD: Outer Diameter. – ID: Inner Diameter. – Angle: (e.g., 45°). – Length: (Height of the arc). 2). Grade: “Is this for a motor?” – We usually recommend H, SH, or UH grades to resist operating heat. 3). Adhesive: “What glue will you use?” – We can ensure coating compatibility. 4). Chamfer: “Is a rounded edge acceptable?” (Mandatory for Epoxy).