30×30 square / 30×17.5 slim mounting sizes
Common hole patterns & brackets. This reference collects installer-ready dimensions for the two most used light-curtain envelope sizes — 30×30 mm square and 30×17.5 mm slim. It includes hole spacing, bracket choices, clearance rules, torque, and retrofit notes for swapping brands without redrilling.
Fit rule: Always verify the protective height (PH), resolution, and optical window offset alongside hole pattern. Mechanical fit ≠ compliance — distance must still satisfy S = K×T + C (ISO 13855).
1) Envelope & hole patterns (typical)
30×30 mm square
| Feature | Typical value | Notes |
|---|
| Profile size | 30 × 30 mm | Extruded aluminum, window centered |
| Rear T-slot width | ~6.0 mm (M4 T-nut) | Accepts slide nut or captive nut strip |
| End-cap holes | M4 × 4 deep (2 holes) | For end brackets; do not exceed 1.8 N·m |
| Side bracket holes | 2 × M4 at 20 mm pitch | Bracket to profile; slot adjustable ±6 mm |
| Through-mount pitch (PH ≥ 450 mm) | ~300 mm typical | One bracket near ends, one mid-span for stiffness |
30×17.5 mm slim
| Feature | Typical value | Notes |
|---|
| Profile size | 30 × 17.5 mm | Window offset to one face; check "A-side" |
| Rear slot | ~4.2 mm (M3/M4 nut) | M3 preferred for compact brackets |
| End-cap holes | M3 × 4 deep | Lower torque than 30×30 |
| Side bracket holes | 2 × M3 at 16–20 mm pitch | Use anti-twist bracket pair |
| Support spacing | ≤ 350 mm | Slim body needs closer supports to resist vibration |
ASCII quick layout
Front view (30×30) Front view (30×17.5 slim)
┌────────────────────┐ ┌────────────────────┐
│ ■ optical win │ │ ■ optical win │ (offset to A-side)
│ │ │ │
└────────────────────┘ 30 mm └────────────────────┘ 30 mm height, 17.5 mm depth
30 mm 17.5 mm
Side bracket holes (typical):
[ M4 ]──20 mm──[ M4 ] [ M3 ]──16–20 mm──[ M3 ]
2) Brackets & hardware (select by stiffness and access)
A. L-bracket (universal)
- Use for side-mount to frame uprights.
- Allows ±5° tilt to avoid mirror reflections.
- Material: 2–3 mm stainless steel or thick aluminum.
B. Rear T-slot sliding set
- Fast pitch adjust along the length; minimal hole drilling.
- Add a mid-span support for PH ≥ 900 mm.
- Use spring nuts to lock position under vibration.
C. End-cap brackets
- Clean look; keep loads axial to avoid cap cracking.
- Do not exceed torque limits; add side support if tall.
| Hardware | Size | Torque (max) | Washer | Notes |
|---|
| Bracket screw (30×30) | M4-0.7 | 1.8–2.0 N·m | Ø8, 0.8–1.0 mm | Use thread-locker (low strength) |
| Bracket screw (30×17.5) | M3-0.5 | 0.8–1.0 N·m | Ø6, 0.6–0.8 mm | Avoid over-torque on slim body |
| T-nut (slot) | M3/M4 | — | — | Prefer spring or serrated type |
3) Clearance & mounting rules (don’t skip)
- Gap to moving parts ≥ 10 mm (mechanical safety) and keep the optical window clear of guards.
- Keep cables away from sharp bends; minimum bend radius ≥ 8× cable diameter.
- For reflective floors/walls, tilt TX/RX by 3–5° or add side hoods.
- On presses/robot cells, add anti-vibration pads but keep TX/RX coplanar.
- Never mount on flexible doors without a stiff sub-frame.
4) Retrofit cross-reference (hole pattern sanity)
| Legacy family | Body class | Mount style | Retrofit hint |
|---|
| Common 30×30 families (multi-brand) | 30×30 | Side L-bracket + rear slot | Often drop-in; verify window center vs die lip |
| Ultra-slim families | 30×17.5 | Rear slot + anti-twist pair | Add mid-support; check offset window orientation |
| Legacy OEM with end-only caps | 30×30 | End-cap | Use an adapter plate to reuse cap holes |
Exact drawings vary by series — confirm with the model datasheet before drilling.
5) Installer worksheet (copy/paste)
Machine: ____________________ Area: ____________________
Chosen body: ☐ 30×30 ☐ 30×17.5 Protective height (mm): ______
Bracket set: ☐ L-bracket ☐ Rear T-slot ☐ End-cap (+side support)
Support spacing (mm): ______ Mid-support: ☐ yes ☐ no
Tilt to avoid reflections: ____° Hoods/baffles: ☐
Screw & torque: M4 __ N·m / M3 __ N·m Thread-locker: ☐
Cable exit: ☐ top ☐ bottom Bend radius OK: ☐
Photos archived (TX, RX, brackets, routing): ☐
6) Common mistakes & fast fixes
| Mistake | Symptom | Fix |
|---|
| Using end-cap only on tall PH | Vibration, intermittent trips | Add side/mid supports; keep span ≤ 300–350 mm |
| Over-torque on slim body | Bracket distortion, optical misalignment | M3 ≤ 1.0 N·m; use washers and low-strength locker |
| Mount perfectly parallel to glass/steel | False trips from reflections | Tilt 3–5°, add matte tape/hoods |
| No allowance for window offset (slim) | Unexpected distance loss | Orient A-side correctly; re-check ISO 13855 distance |
AuthorDAIDISIKE Safety Engineering Team
Reviewed byChief Safety Engineer · 20+ years industrial safety · IEC 61496 reference
Last verified2025-01
Foshan DAIDISIKE Optoelectronics Technology Co., Ltd.
