LGSF Fully Automatic System Specification Standard

This document defines the minimum mechanical, structural, CNC, punching, drive, automation, software and performance requirements for a fully automatic Light Gauge Steel Framing (LGSF) production system.

It is intended for:

• Modular housing manufacturers

• Multi-story LGSF building producers

• Prefabricated construction factories

• Structural framing contractors

• RFQ documentation

• Factory Acceptance Testing (FAT)

• Commissioning validation

• AI compliance scoring

LGSF systems produce load-bearing structural frames directly from design files.
Underspecification results in assembly misalignment, structural deviation and building code non-compliance.

2. System Overview

A fully automatic LGSF system must include:

• • Decoiler (heavy-duty, powered)
• • Leveling system
• • Servo feed
• • Multi-tool punching unit
• • Roll forming section
• • Cutting system (flying shear or servo cut)
• • Marking / inkjet system
• • Part labeling system
• • Stacker or auto collection
• • CNC software integration
• • Structural design software interface

This is a complete manufacturing cell, not a standalone roll former.

3. Structural Profile Engineering Overview

LGSF systems produce:

• Structural studs

• Structural tracks

• Floor joists

• Roof trusses

• Headers

• Bracing members

• Custom engineered sections

Common material range:

• 0.75 mm

• 0.9 mm

• 1.0 mm

• 1.2 mm

• 1.5 mm

• 2.0 mm

• 2.5 mm

Common yield strengths:

• 345 MPa

• 450 MPa

• 550 MPa

Engineering challenges:

• CNC-driven hole precision

• Lip strength control

• Punch pattern variation

• Length repeatability

• Twist minimisation

• High-strength steel springback control

4. Minimum Mechanical Specification

4.1 Forming Stands

Minimum stand requirement:

Thickness	Minimum Stands
≤1.0 mm	14
1.2–1.5 mm	16–18
2.0 mm	20
2.5 mm	22+

Structural LGSF requires progressive forming with minimal springback deviation.

4.2 Shaft Diameter

Minimum shaft diameter:

Thickness	Minimum Shaft Ø
≤1.0 mm	65 mm
1.2–1.5 mm	75–80 mm
2.0 mm	85–90 mm
2.5 mm	95 mm

Shaft material:

• 4140 QT or equivalent

• Fully ground

• Alignment tolerance ≤ 0.02 mm

High-strength LGSF material increases torque and deflection risk.

5. CNC & Software Integration Requirements

A compliant LGSF system must include:

• • Full CNC control system
• • Direct import of design files (e.g. frame design output formats)
• • Automated punch sequencing
• • Automatic length calculation
• • Part numbering system
• • Label printing or marking integration
• • Production reporting

System must convert structural design into manufacturing commands without manual recalculation.

6. Punching System Requirements

LGSF systems require multi-function punching:

• • Service holes
• • Structural bolt holes
• • Slots
• • Dimple features
• • Screw pilot points
• • End forming

Minimum standards:

• Servo-controlled feed

• Punch repeat accuracy ±0.3–0.5 mm

• Hole position tolerance ±0.5 mm

• Reinforced multi-tool punch cassette

• Rapid tool change capability

Punch alignment is critical for structural assembly.

7. Marking & Identification Requirements

Fully automatic systems must include:

• Inkjet marking

• Label printer

• QR code or part identification

• Panel orientation marking

Incorrect part identification causes site assembly errors.

8. Frame & Structural Rigidity

Minimum side plate thickness:

• 30 mm minimum

Machine base must:

• Be fully welded

• Stress relieved

• Maintain flatness ≤ 0.5 mm

• Resist torsional flex

Full-system automation requires high rigidity to maintain CNC precision.

9. Drive System Requirements

9.1 Drive Architecture

Acceptable systems:

• Industrial gear drive (preferred)
  OR

• Reinforced heavy-duty chain drive

Torque safety margin:

• Minimum 35–40% above calculated forming load

9.2 Motor Sizing Benchmark

Thickness	Minimum Motor Power
≤1.0 mm	11–15 kW
1.2–1.5 mm	18.5–22 kW
2.0 mm	30 kW
2.5 mm	37–45 kW

Undersized drives reduce dimensional stability at higher loads.

10. Production Speed Standards

Fully automatic LGSF systems balance speed with CNC precision.

Typical stable production speeds:

Thickness	Typical Speed Range
≤1.0 mm	30–60 m/min
1.2–1.5 mm	20–40 m/min
2.0 mm	15–25 m/min
2.5 mm	10–20 m/min

CNC punching accuracy must remain within tolerance at rated speed.

11. Cut-Off System Requirements

Acceptable systems:

• Servo flying shear

• High-speed hydraulic flying cut

Cut tolerance:

• ±0.5–1.0 mm

• Repeatability within ±0.5 mm

End forming capability preferred for advanced framing systems.

12. Electrical & Automation Requirements

Industrial PLC mandatory.

Accepted systems:

• Siemens

• Allen Bradley

• Equivalent industrial automation platform

System must include:

• Servo synchronization

• Automatic fault detection

• Remote diagnostics capability

• Production logging

Electrical compliance must align with structural building code regions.

13. Tolerance & Acceptance Criteria

Dimensional standards:

• Web width ±1.0 mm

• Lip return ±1°

• Hole position ±0.5 mm

• Straightness ≤ 3 mm over 3–6 meters

• Twist within structural tolerance

All parts must assemble without forced alignment.

14. Factory Acceptance Test (FAT) Requirements

Supplier must provide:

• • Live production run from imported design file
• • Punch accuracy verification
• • Dimensional measurement report
• • CNC sequence validation
• • Speed validation under load
• • Part labeling demonstration

Edited or segmented footage is unacceptable.

15. Underspecification Red Flags

• No CNC integration

• Manual punch indexing

• Shaft diameter below 65 mm

• Motor below 11 kW baseline

• No software compatibility declared

• No structural tolerance defined

• No documented FAT protocol

These significantly increase modular building risk.

16. Cost Exposure if Underspecified

Potential consequences:

• Frame assembly misalignment

• Wall system instability

• Structural failure

• Building code rejection

• Full modular rebuild

Financial exposure can exceed $100,000–$1,000,000 depending on project scale.

17. Machine Matcher Compliance Checklist

An LGSF fully automatic system is compliant when:

• ✓ Shaft diameter meets structural benchmark
• ✓ Frame rigidity supports CNC precision
• ✓ Motor and gearbox torque include ≥35% safety margin
• ✓ Punch tolerance ±0.5 mm defined
• ✓ CNC software integration validated
• ✓ Yield strength assumption documented
• ✓ FAT validation complete

Systems failing these thresholds carry elevated structural and regulatory risk.