Cause: Mislocated Welds

The weld has been placed in the wrong location on the part by fixture, robot or operator, or has been omitted completely.

Description 

Assembly weld locations do not match specified weld locations.

Detection 

Detectable evidence may include:

• Excessive indentation
• Expulsion/burn through
• Extra welds
• Inconsistent weld quality
• Mislocated/edge welds
• Missing weld
• Poor Class A appearance
• Sheet metal distortion
• Weld spacing too close together
• Weld spacing too far apart
• Irregular weld spacing
• Welds on radius of part

Significance 

Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition. Special considerations are noted below:

Quality: Unacceptable Class A finish may result; the assembly may be excessively noisy, or it may vibrate, or display reduced smoothness of operation.

Subordinate Causes

Manual weld guns:

• Wrong cables/shunts
• Weld control adjustment (in repeat operation) provides inadequate time to move gun to next weld location
• Cycle time of part in the welding station too short to properly place all welds
• Inadequate operator training

Robotic guns:

• Robot improperly programmed
• Fixture guns
• Guns positioned in wrong location along flange
• Offset electrodes rotated to incorrect position