Overview

If the FieldPrinter stops and no physical obstacle is present, the floor surface itself may be triggering the robot's obstacle detection sensors. This is expected behavior.

Symptoms

• The FieldPrinter stops mid-print with no visible obstacle in its path.
• The robot stops repeatedly in the same area or on the same floor type.
• Stopping occurs more frequently on certain floor surfaces, including:
  • Polished or sealed concrete
  • Epoxy-coated floors
  • Glossy tile
  • Wet or moist surfaces
  • Any floor with high reflectivity or sheen

Cause

The FieldPrinter uses sensors to detect obstacles and stop safely before a collision. On highly reflective, glossy, shiny, or moist surfaces, these sensors can misread the floor's reflection as an obstacle — a false positive. This triggers a safety stop even though nothing is physically in the way.

This is expected behavior. The robot's sensors are working as designed. Certain floor conditions are simply more likely to produce false positives.

What to Do

Resume Printing

When the robot stops due to a false positive:

1. Confirm there is no actual obstacle in the robot's path.
2. On the iPad, follow the on-screen prompt to resume the print job.
3. The robot will continue from where it stopped.

Reduce the Frequency of False Positives

False positives cannot always be fully eliminated on challenging surfaces, but the following may help:

• Avoid printing when the floor is wet or freshly mopped. Allow the surface to dry fully before running the FieldPrinter.
• If the floor is permanently reflective (epoxy, polished concrete, sealed tile), expect occasional stops and plan for a slightly longer print session.
• Check for localized reflections — puddles, wet spots, or patches of high-gloss coating are common culprits. Clearing or drying the immediate area can reduce stops.