Sanjun Custom Sheet Metal Solutions for Power Service Self-Service Terminals: Precision, Durability & Seamless Design

Core Pain Points Addressed for Power Service Self-Service Terminals

1. Complex Arc Bending Precision:

   Full-arc frame designs (the defining feature of these terminals) require consistent bend angles (±0.1° tolerance) across all panels—standard press brakes fail to maintain uniformity, leading to misaligned assemblies.

2. Flawless Matte Finish:

   Matte (flat-gloss) powder coatings show even minor surface irregularities (≥0.05mm bumps) under side lighting—off-the-shelf fabrication results in visible defects that harm utility brand perception.

3. Air-Spring Door Gap Control:

   Air-spring (lock-free) doors demand a maximum gap of 0.3mm between the door and frame (to prevent dust ingress) while maintaining smooth opening/closing—imprecise sheet metal fitting causes either gap leaks or door jams.

4. Public-Use Durability:

   Terminals in government buildings/power offices face daily user contact, requiring scratch-resistant sheet metal that resists 5,000+ touch cycles without surface degradation.

5. Device Integration Accuracy:

   Cutouts for touchscreens, card readers, receipt printers, and biometric scanners need ±0.05mm tolerance—misalignments delay deployment and cause user friction.

Sanjun’s Custom Sheet Metal Solutions for Power Service Terminals

1. Complex Arc Bending Precision Solution

• Advanced Bending Equipment & Techniques:
  • AMADA HFE 1003NT CNC press brakes (with 6-axis backgauges and adaptive bend control) to form 1.5mm SPCC cold-rolled steel into full arcs (radius range: 50–120mm) with ±0.1° angle tolerance.
  • 3D-printed bend jigs (customized for each terminal’s arc profile) to ensure consistent bend radius across all panels—eliminating assembly misalignment.
• Post-Bend Calibration:

  Coordinate Measuring Machine (CMM) checks for arc dimensional accuracy (±0.05mm) after bending; robotic sanding (120-grit abrasive) to smooth bend edges and remove micro-imperfections.

2. Flawless Matte Finish Solution

• Pre-Coating Surface Preparation:
  • 2-stage chemical cleaning (degreasing + phosphating) to remove all surface contaminants; robotic sandblasting (80-grit aluminum oxide) to create a uniform 0.02mm rough texture (ideal for matte coating adhesion).
  • Zero-defect sheet metal inspection (using side lighting at 45°) to reject panels with ≥0.03mm bumps before coating.
• Robotic Matte Coating:
  • High-pressure robotic powder coating (60μm thickness) with flat-gloss (5–10 GU) formulation—calibrated via gloss meter to ensure no gloss variation across panels.
  • Post-curing oven cooling (controlled 2°C/min rate) to prevent coating warping that causes surface irregularities.

3. Air-Spring Door Gap Control Solution

• Precision Door & Frame Fabrication:
  • Laser-cut door panels (±0.03mm tolerance) with CNC-bent edges (R2mm) to match the terminal’s arc profile.
  • Frame recesses (CNC-machined into the main cabinet) to seat the door’s air-spring hinges (model: SUSPA C16-063) with ±0.02mm alignment.
• Gap Calibration:
  • Adjustable air-spring mounting brackets (welded to the door) to fine-tune the door’s position; feeler gauge checks (0.3mm max) to verify gap uniformity around the entire door perimeter.
  • Door seal integration: 0.5mm-thick EPDM rubber gaskets (custom-cut to the door’s arc) to fill the 0.3mm gap while maintaining smooth air-spring operation.

4. Public-Use Durability & Device Integration

• Durable Material Selection:
  • Frame panels: 1.5mm SPCC cold-rolled steel (tensile strength ≥350 MPa) with matte powder coating (abrasion resistance: ≥5,000 cycles per JIS K 5600).
  • High-contact areas (touchscreen bezel): 1.2mm 304 stainless steel (brushed 100-grit finish) to resist scratches from user interactions.
• Micron-Level Device Cutouts:

  4000W fiber laser cutting for touchscreens (15–21-inch), card readers (e.g., 80mm×50mm), and receipt printers (120mm×60mm) with ±0.05mm tolerance—ensuring perfect alignment and no loose fits.

  Hidden 20×30mm cable channels (integrated into the arc frame) to route wiring and protect it from dust.

Production & Quality Assurance

1. Arc Profile DFM Review:

   Pre-production design reviews to optimize arc bend sequences (reducing springback) and ensure compatibility with air-spring door hardware.

2. Automated Precision Manufacturing:

• Robotic loading/unloading for press brakes to eliminate human error in arc bending.
• Robotic powder coating to ensure uniform matte finish thickness (±2μm).

3. Critical Quality Checks:

• Arc Accuracy: CMM verification of arc radius and bend angle (±0.05mm/±0.1°).
• Finish Quality: Side-light inspection (45° angle, 500lux lighting) to detect surface irregularities ≥0.03mm.
• Door Gap: Feeler gauge testing (0.3mm max gap) and 1,000-cycle air-spring door operation test.

4. Infrastructure-Grade Packaging:

   Custom foam inserts (shaped to the terminal’s arc frame) + ISPM 15 crates to protect the matte finish and arc panels during shipping to utility locations.

Client Case Study: Regional Power Utility Terminal Deployment

• Client: A European regional power utility (200+ service centers across 3 countries).
• Pain Points: Need for full-arc terminals with matte finishes, 0.3mm air-spring door gaps, and 20-day delivery for 500 units.
• Sanjun’s Solutions:
  1. AMADA CNC press brakes + 3D bend jigs for uniform full-arc frames.
  2. Robotic matte coating + side-light inspection for flaw-free surfaces.
  3. Precision air-spring door fitting with 0.3mm gap calibration.
• Outcomes:
  • 0 assembly misalignment reports across 500 units.
  • 99.8% of terminals passed side-light finish inspection (no visible defects).
  • Air-spring doors operated smoothly with 0.25mm average gap (meeting IP54 dust resistance standards).

FAQ