Cause: Incorrect Cylinder

Definition
The weld cylinder will not provide the proper range of electrode force or motion.

Description
The weld cylinder serves two primary functions:

1. The cylinder stroke separates the electrodes to allow part access
2. The cylinder closes the electrodes on the workpiece to provide the required welding force

The following is a basic list of cylinder characteristics which must be considered for proper equipment function: bore, stroke, single or dual action, type (air, hydraulic, or hybrid), seal type, shaft length, overall length, mounting details, cushions, etc.

Detection
Detectable evidence may include:

• Cracks & holes
• Excessive indentation
• Expulsion/burn through
• Inconsistent weld quality
• Nonround weld
• Poor Class A appearance
• Sticking/stuck tips
• Stuck weld
• Undersized weld
• Gun will not completely close
• Incorrect force
• Off-location welds
• Part access difficulties
• Short cylinder life
• Short electrode life
• Visual inspection

Significance
Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition.

Subordinate Causes

• Correct cylinder unavailable
• Improper maintenance
• Incorrect nameplate
• Incorrect rework

Notes
Similar considerations may be applied to servo motor systems.