Machine Noise, Vibration, and Overheating

The operator who runs a machine every day knows its sounds best. After a while you know how it normally turns and sounds; when the sound changes one day, nine times out of ten something is wrong. Unusual noise, vibration, and overheating are all warning signs from the machine, and the sooner you deal with them, the easier the repair.

What to Do About Strange Noises

First identify the type of sound:

• Metal rubbing or scraping: A part may be loose or out of position, or a foreign object may be stuck in a moving part.
• Rhythmic knocking: Something may be loose and striking with each rotation.
• High-pitched squealing: A drive component may be slipping or lacking lubrication.
• Dull groaning with slower speed: The load is too heavy, for example because the ingredients are too hard or there's a blockage.

The general rule: if you hear a sound that isn't normally there, stop the machine. Don't think "I'll finish this batch first."

Increased Vibration

• The machine isn't sitting level: Uneven floor, loose feet, or the machine was moved.
• Loose parts: Not tightened after cleaning.
• Ingredient problems: Ingredients that are too hard, or blockages, make the load fluctuate.
• Drive or rotating component problems: These need professional inspection.

Motor Overheating

It's normal for a motor to be warm while running, but if the housing is too hot to touch, you smell burning or plastic, or there's even smoke, that's abnormal. Common causes:

• Overload: Ingredients too hard or dry, or a feed blockage, so the motor is constantly straining. See Filling Blockages and Uneven Feeding.
• Poor cooling: Items piled around the machine, or cooling vents clogged with flour dust.
• Unstable power or wiring problems: Low voltage or poor contact. See Electrical Problems: Tripping and Failure to Start.
• Long continuous operation beyond how the machine was designed to be used.

Safe Checks You Can Do Yourself

Before checking anything by hand, press stop, turn off the power, and unplug the machine or cut the main switch, and make sure the machine has come to a complete stop. In factories with multiple workers, lock the switch and hang a "Under maintenance, do not energize" tag. Article 57 of Taiwan's Occupational Safety and Health Facilities Rules (職業安全衛生設施規則) requires that when machinery is being cleaned, oiled, inspected, repaired, or adjusted, operation and feeding must be stopped, and measures such as locking out and posting signs must be taken to prevent accidental start-up.

Article 43 of the same Rules also requires that hazardous parts such as prime movers, shafts, gears, pulleys, and drive belts be fitted with guards, enclosures, or similar equipment. So when inspecting, don't remove the guards and then run the machine to watch; never operate it with the guards removed.

Once the power is off, the machine has come to a complete stop, and it has cooled down, you can:

1. Check whether the machine is sitting level and whether the feet are loose.
2. Following the operating manual, confirm all detachable parts are correctly reinstalled and tightened.
3. Check the hopper and passages for foreign objects or blockages.
4. Clear dust from the cooling vents (with a dry cloth or brush; don't spray water on electrical parts), and move clutter away from the machine.
5. Confirm the ingredients are of normal firmness.

When to Stop and Call for Service

In the following situations, stop the machine and cut the power immediately, and don't restart it to test:

• You smell burning, or see smoke or sparks.
• The housing or motor is too hot to touch.
• You hear metal banging or breaking sounds.
• Vibration is severe or getting worse.
• Liquid (oil, water) is seeping from places it shouldn't.
• The abnormal noise remains after the simple checks above.

When calling for service, describe the situation clearly so the technician can diagnose it faster: the machine model, when it happened, what the sound was like, during which motion it occurs, and whether you've recently changed ingredients or moved the machine. If possible, record the sound or a video from a safe distance. For more, see When to Fix It Yourself vs. When to Call Service.

FAQ

Q: Can I keep running the machine if it makes a strange noise?
A: Not recommended. If you hear a sound that isn't normally there, stop first and find the cause before running again.

Q: Is it normal for the motor to be very hot?
A: Being warm is normal, but too hot to touch, a burning smell, or smoke is abnormal; stop and cut power immediately.

Q: Can I deal with increased vibration myself?
A: After cutting power, you can check whether the machine is level, whether parts are tightened, and whether there's a blockage; if it still vibrates, call for service.

Q: When must I call for service?
A: Burning smell, smoke, sparks, metal banging, severe vibration, or abnormal noise that remains after simple checks: stop the machine, cut the power, and contact the manufacturer or a service provider. Dong-Yih Machinery: 06-257-4644.