Stable linear welds

Precision Seam Welding

A process loop for thin sheet, enclosure, and precision seam weld parameter control.

Main challengeSeam repeatability

Small changes in gap, part flatness, or path height can shift penetration and bead width.

Hold firstPath + focus

Stabilize path tracking, focal position, and fixture contact before tuning heat input.

Proof pointsStart / middle / end

Inspect representative seam positions, plus corners and acceleration zones where present.

Precision seam workflow

Step	What to control	Evidence to keep
Joint fit-up	Measure gap, mismatch, and part flatness along the seam.	Record maximum gap and mismatch before welding.
Path control	Confirm robot/CNC path, acceleration zones, and focus height over the full seam.	Flag corners, starts, stops, and fixture transitions.
Parameter sweep	Adjust speed and power in small steps while keeping gas and fixture fixed.	Compare bead width, penetration, undercut, and distortion.
Production check	Repeat accepted settings on multiple parts before widening the process window.	Look for drift from heat buildup, fixture wear, or part tolerance.

Pattern	Likely driver	Next action
Good center, weak ends	Start/stop timing, entry/exit shielding, or acceleration mismatch.	Inspect the seam start/stop program, ramp profile, and gas lead/lag timing.
Corners overheat	Robot or CNC slows at direction change while power stays high.	Tune path speed profile or power compensation before moving the nominal recipe.
Penetration drifts after several parts	Fixture heat buildup, part stack-up, or optics contamination.	Record part count to drift, fixture temperature, and protective-window condition.
Bead width varies side to side	Joint gap, tracking error, or unstable focus height.	Check path alignment to the joint centerline and part flatness across the seam.

Check	Minimum requirement	Why it matters
Seam map	Pass sample at start, middle, end, and every seam feature that changes path behavior.	A single straight-line coupon does not prove a real production seam.
Window edge	Know the first failing low-heat and high-heat condition around the accepted recipe.	Defines process robustness instead of a single nominal setting.
Fixture repeatability	Verify accepted settings on multiple loads and unloads, not one clamped sample.	Precision seams often fail from variation in setup repeatability rather than formula error.
Inspection record	Photo set, dimensions, cross-sections, and rejected conditions logged together.	Lets the next shift or engineer rebuild the approved setup without guesswork.