Dukane 403570-01 User Manual page 81

Table 9–I Welding Process Troubleshooting
Problem Symptom
Excessive weld flash
Overwelding Welded assembly
dimensions are too
small
Low strength weld
Underwelding Welded assembly
dimensions are too
large
Excessive weld flash
Low weld strength
Nonuniform or
inconsistent
Failure when leak
weld joints
tested
Part failure in service
Final part
orientation
Parts not aligned
different from
properly
programmed
orientation
Dukane Manual Part No. 403-570-01
Possible Cause
Weld Time or Distance are too large
Incorrect flash trap design
Weld Time or Distance are too small
Material difficult to weld due to low friction
coefficient
Warped parts
Uneven weld interface
Fixture and part are not parallel
Poor alignment of parts in tool and/or
fixture
Insufficient fixture support
Part walls flexing during weld
Excessive filler or uneven distribution
Moisture in parts
Deceleration too low
Vertical speed too high
Poor tuning
Parts not held properly by tool or fixture
Section 9 - Troubleshooting
Recommended Solution
Reduce Weld Time or Distance
Evaluate and correct flash trap design
Increase Weld Time or Distance
Degrease joint interface to remove mold release
agent
Consider changing material (i .e . avoid PTFE)
Check part dimensions
Check molding process conditions
Level fixture where necessary
Check that tooling is true to table
Change part or tool dimensions
Improve part tolerance due to cavity
Check for parts shifting during welding
Provide features in parts for rotational driving (i .e .
drive ribs or cavities)
Redesign parts with reinforcing ribs and/or tongue-
and-groove joints
Reduce amount of filler
Improve processing conditions to ensure even
distribution of filler
Prevent moisture absorption after molding prior to
welding
Dry parts before welding
Increase spin deceleration as high as possible (if
set too high, welder will fault with tracking errors)
Reduce speed to decreased spin torque required
Determine and enter tool inertia correctly into Setup
Contact DUKANE for special tuning requirements
Ensure tooling does not allow excessive play
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