A timing pulley pressed onto a shaft. It slipped under load after two months. The press fit was supposed to hold. I’d specified H7/p6 — a standard interference fit. But I’d never calculated the actual…
A customer called me last week. “My cylinder won’t push the slide. I turned the air up to 8 bar and it still stalls.” I asked him what bore it was. “Ø32.” I asked what…
A profile rail on a reciprocating axis. It failed after 8 months. The customer said it was too cheap. It wasn’t cheap — it was a standard 25 mm rail from a reputable maker. The…
I watched a mechanic torque an M8 bolt to 25 N·m with a wrench. “That’s standard,” he said. I asked him what preload that gave him. He shrugged. I don’t blame him — torque wrenches…
Last month I was building a weld fixture. The arm was 300 mm long, Ø25 mm steel, holding a 15 kg part at the tip. I drew it up, sent it to the shop, and…
The Line Where One Operator Was Always Behind A manual assembly line had five workstations. The tasks were divided by part (Station 1: left side, Station 2: right side, and so on). After two weeks,…
The Air Compressor That Ran All Night for No One A customer’s compressed air system ran every night, even though production stopped at 6 p.m. The production manager said, “The machine needs air to hold…
The Vision System That Took a Picture and Never Finished A customer installed a vision inspection station on a high-speed line. The camera triggered on a photoeye. The inspection (a pass/fail on a label) was…
The Cylinder That Slammed Into Its Stops A pick-and-place cylinder extended at full 6 bar pressure. The customer wanted it faster. They opened the flow control all the way. The cylinder shot across 200 mm…
The Rework Batch That Jumped the Queue A customer ran a production cell that had to maintain FIFO (first-in, first-out) — the first part loaded had to be the first part unloaded. It was a…
The Conveyor That Was Twice as Fast as It Needed to Be A packaging line had a belt conveyor running at 30 m/min. The design said “as fast as possible.” The result: the product arrived…
The Conveyor That Was Twice as Fast as It Needed to Be A packaging line had a belt conveyor running at 30 m/min. The design said “as fast as possible.” The result: the product arrived…
The Robot That Moved Fast but Took Forever A pick-and-place robot was programmed to move at 100% speed. The cycle time was 6 seconds per pick. The customer wanted it faster. We looked at the…
The Line That Starved Every Time the Robot Blinked A two-station assembly cell had no buffer between the stations. Station A picked and placed a part (cycle time 4 s). Station B assembled it (cycle…
The “90% Uptime” That Was Really 55% A customer reported their line ran at “90% uptime.” The plant manager was proud. We asked what they meant by uptime. They said: “the machine was on, not…
