A hydraulic arm holds a load mid-stroke. It slowly sinks. You pull the cylinder, replace the seals, and it still drifts. The seals weren’t the problem. The counterbalance valve was never adjusted. Why a vertical…
A photoelectric sensor watches parts go by on a conveyor. It sees one part, misses the next. The lens is clean. The bracket is flexing. The sensor-to-part distance is bouncing in and out of range…
A plate comes out of the press three millimeters bowed. You heat it with a torch to straighten it, it moves back, then twists again next week. The fix isn’t post-weld straightening. It’s controlling distortion…
A new VFD whines like a mosquito. The customer calls and says the motor is defective. You bump the carrier from 2 kHz to 8 kHz. Quiet now, but the drive is running hot and…
You order a bearing with C3 on the end of the part number. The guy at the counter says fine, ships it. Six months later the motor is humming hot and noisy. You pull the…
A welded bracket on a machine that cycles 20 times per minute. It cracked at the weld toe after 6 months. The weld looked fine. The static strength was fine. It failed in fatigue. The…
I was asked to measure the deflection of a welded frame under load. I mounted a strain gauge on the frame, wired it to a signal conditioner, and read the output. The number bounced around…
A gear reducer on a conveyor. It was rated for 500 N·m output torque. The conveyor needed 200 N·m (40% load). After two hours of operation, the reducer housing was too hot to touch (85°C)….
A pneumatic cylinder that took 0.8 seconds to extend over 100 mm. The customer wanted 0.3 seconds. The cylinder was fine. The tube from the valve to the cylinder was 6 mm ID, 5 meters…
A servo motor coupled to a ball screw. The axis had 0.1 degrees of lost motion at the motor shaft. The customer thought the servo was missing steps. It wasn’t. The coupling was a jaw-type…
A compressed air system at a customer’s plant. The compressor cycled on every 3 minutes even though no machine was running. I put a ultrasonic leak detector on the lines. It found 12 leaks. The…
A vacuum gripper on a pick-and-place robot. It couldn’t hold a perforated cardboard box. The customer thought the vacuum pump was weak. It was a small venturi ejector. The box leaked. The ejector couldn’t pull…
A ball screw axis that vibrated violently above 2000 RPM. The customer thought the servo tuning was off. It wasn’t. The screw was approaching its critical speed — the natural frequency of the screw as…
A fixture that locates a part within ±0.1 mm. The parts were 0.3 mm off. I ran the tolerance stackup. The design had four dimensions in the chain, each with ±0.1 mm tolerance. Worst case:…
I’ve seen FEA models that show a stress concentration at a bolt hole. The engineer read the peak stress as 450 MPa and flagged the part for failure. But the peak was at the center…
