🦷 Field Diaries: Episode 3

The Conveyor Case & the Damaged Tooth

🗓️ The Situation

Today’s job was a routine vibration survey on a conveyor drive system, consisting of a motor and gearbox assembly. These kinds of surveys are part of the client’s ongoing predictive maintenance program but this one came with a complaint attached:

“There’s a strange noise coming from the gearbox.”

🔍 The Diagnosis

After taking readings on both the motor and gearbox, the data pointed clearly to the source: impacting occurring once per input shaft revolution. Additionally, there was elevated sideband activity around the input gear mesh frequency, indicating modulation consistent with gear damage.

All signs pointed to a likely damaged tooth on the gearbox input gear, as confirmed through vibration analysis. But as always, physical observations matter just as much, and in this case, the gearbox was making more noise than a toddler at the dentist.

Most people go to the dentist for a damaged tooth. This one booked an appointment with me, and let’s just say, I don’t do fillings... I do full-blown mechanical surgery.

🧠 The Recommendation

I advised the client to schedule a gearbox replacement as soon as possible. Fortunately, they already keep spare gearboxes in stock for exactly this kind of situation, a textbook example of forward thinking maintenance planning.

Waiting another two months for the next scheduled shutdown could easily turn a contained issue into an unplanned failure with production losses. That’s not a gamble worth taking.

⚙️ Why It Matters

This is why routine vibration surveys are invaluable, not just for catching problems early, but for knowing exactly how serious they are. In this case, the machine was still running, but the data told the real story: this gearbox had entered the countdown phase.

Planned maintenance keeps control in your hands. Unplanned downtime takes it away and usually takes profits with it.

✅ Closing Notes

The client appreciated the clarity and decisiveness of the report. With a spare gearbox already on hand, the decision was easy: plan the change and avoid the pain.