The Robot That Lost Its Mind at 6 a.m. A six-axis welding robot started faulting at random — encoder error here, communication timeout there. It happened once a shift, always around the same time. The…
The Filter That Was “Saved” Too Long A maintenance department had a rule: change the FRL filter every 12 months, like clockwork. On a dirty stamping plant, the differential pressure gauge on the filter sat…
The Belt That Slipped on Day One A conveyor was installed, aligned, and tested. The first week, it ran fine. The second week, the belt started slipping under load — the motor hummed, the belt…
The Bearing That Was Greased to Death A maintenance department had a rule: “grease every bearing every month.” It sounded diligent. On a 75 kW fan motor, the technician pumped grease until it oozed out…
The Broken Sensor That Cost a Day A proximity switch failed on a packaging line at 2 a.m. on a Saturday. The maintenance tech called the supplier — nobody answered. The line was down until…
The Machine That Ate Its Own Bearings A customer ran an indexer 24/7. The production manager told me “we fix it when it breaks.” Six months in, the indexer’s bearings failed catastrophically — the gearbox…
The Light Curtain That Tripped When Nobody Was There A stamping press had a safety light curtain across the operator access. Every time the press cycled, the light curtain tripped out — even when the…
The Ultrasonic Sensor That Chose the Wrong Lid A customer came to us with a level measurement problem. They were measuring the fill level in a plastic hopper using an ultrasonic sensor, and the reading…
The Laser That Read the Mirror as Infinity I once specified a laser distance sensor to measure the height of a stack of cardboard boxes on a palletizer. The datasheet promised 0.1 mm resolution over…
Why the Machine Lost Its Position After a Power Cycle A packaging line I worked on used an incremental encoder on the feed axis. Every morning, the operator turned on the machine, and the axis…
The Temperature Reading That Drifted (Thermocouple) We measured a temperature (a heater, 100°C). We used a thermocouple (type K). On the floor, the reading drifted (it read 95°C, not 100°C). The problem: the thermocouple’s cold…
The Pressure Switch That Chattered: Dead Band and Pulsation, Not the Switch A pneumatic pressure switch detecting line pressure. It chattered (on-off-on-off) as the pressure fluctuated. The customer thought the switch was failing. The switch…
The Limit Switch That Broke: Roller Arm Life, Not the Switch A mechanical limit switch on a conveyor. It was actuated by a cam on the conveyor chain. The switch broke every 2 months. The…
The Inductive Sensor That Didn’t Trigger: Small Target Sizing, Not the Sensor An inductive proximity sensor (M12, 8 mm rated range) detecting a 5 mm steel bolt. The sensor didn’t trigger. The bolt was too…
The Photo Eye That Saw the Background: Background Suppression, Not the Sensor A photoelectric sensor detecting a box on a conveyor. It triggered randomly. The box was 200 mm away. The background (a steel wall)…
