Seam tracking lets the robot find and follow the actual position of the joint instead of relying purely on the programmed path. It is a powerful option — but it is not needed on every project, and knowing when it pays off is part of good system design.
When it helps
On large fabricated parts, the position of the joint naturally varies: plates are cut with tolerance, parts move slightly during tack welding, and heat moves the joint during welding itself. Where that variation is larger than the welding process can absorb, tracking keeps the weld exactly where it needs to be.
What to consider
- Cycle time. Depending on the setup, tracking can add measurement time to the cycle. On long seams the effect is small; on very short welds it can matter.
- Maintenance. A sensor is an additional component that needs periodic cleaning and calibration.
- Fixturing. On small, well-fixtured parts, a good fixture often solves the problem more simply than a sensor.
Beyond path correction
The most capable systems do more than follow the joint: they measure the gap and adjust the welding parameters as they go, turning a variable joint into a consistent weld.
How to decide
Measure before you specify. Checking how much the joint position actually varies over a series of real parts takes very little time — and it answers the question far more reliably than any datasheet.