Engineering guide for welding fixed bottom cups onto 48.3mm scaffolding tubes. Details weld penetration, torque resistance tests, and pneumatic fixture alignment.
Fixed Bottom Cup Welding Architecture
Cuplock scaffolding standards rely on permanently welded bottom cups located at 500mm intervals to support cross-ledgers. Because these cups endure immense tensile and shear loads when ledgers are locked into position, weld integrity is paramount. The Cuplock Bottom Cup Welding Machine automates this circular weld pass using precision pneumatic rotary tooling.
Operational Welding Matrix
| Machine Element | Setting | Technical Note |
|---|---|---|
| Torch Angle | 45° Inclination | Directs arc root into cup-tube junction |
| Wire Feed Rate | 7.5 - 9.0 m/min | Continuous push feed with anti-backlash roller |
| Welding Current | 210 - 240 Amps | Deep root penetration into 3.2mm tube wall |
| Cycle Time | 22 - 26 Seconds | Includes clamp, arc strike, 360° rotation & unclamp |
| Shear Test Requirement | BS 1139 Part 5 | Withstands min 30 kN axial push-off force |
Preventing Spatter Inside Cup Cavities
A frequent defect in manual welding is weld spatter adhering to the internal spherical contour of the bottom cup, which prevents the forged top cup from sliding down and locking. Automated machine welding controls arc length tightly, virtually eliminating interior spatter and preserving clean ledger pocket tolerances.
Before cup welding, tubes undergo sizing and swaging via the Scaffolding Pipe Swaging Machine to form integral spigot connection ends.
Senior Machine Tool Design & Production Engineering Division, Ludhiana Works
Authored by machine tool builders at our Ludhiana manufacturing works. Every technical parameter, metallurgy guideline, electrical formula, and production cycle stated in this guide is reviewed by our shop-floor engineers who assemble, wire, and execute material trials before global dispatch to GCC and domestic manufacturing facilities.
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