Cause: Incorrect Cylinder

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

Description 

The weld cylinder serves two primary functions:

• The cylinder stroke separates the electrodes to allow part access
• 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
• Non-round weld
• Poor Class A appearance
• Sticking/stuck tips
• Stuck weld
• Undersized weld
• Gun will not completely close
• Weld force too high or too low
• 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

Note: Similar considerations may be applied to servo motor systems.