Servo feeders are finely-meshed workhorses in current automation, essential to provide materials such as stamping blanks of metal or electronic component pieces with staggering accuracy and repeatability. Nevertheless, they, being advanced machinery could have a problem. Knowledge of the usual troubles that occur and their diagnosing nature reduces expensive downtime. A simple guide to shortcomings of your servo feeding system:
1. Feeding Inaccuracy (Wrong Length / Position):
Symptoms: Relentlessly Long or Short pieces or nonstandard parts, and other sections that have non prescribed distances independent of suitable programming.
Diagnosis & Fix:
●Check Material Thickness Setting: The setting of the material thickness: Make sure the set material thickness is the right one set to stock material. Little things on near feeds cause great mistakes on far feeds.
●Inspect Feed Rolls: Look out for worn, damaged and/or contaminated (oils, grease, debris feed rolls). Replace when the need be. Be right in roll pressure, too tight the material would slip, too tight can deform material.
●Verify Roll Diameter: Test against the program correspond Diamond size (or circumference) of the roll is correct. Measure and record the worn rolls and revise the parameter.
●Assess Backlash: Inspect Mechanical Rattle in the drivetrain (gearbox, Couplings) Perform or modify the backlash compensation procedure of the system, in case they exist.
●Encoder/Servo Motor Feedback: The encoder cable that provides motor feedback (servo cable) needs to be plugged securely (and have no damage). Excessive motor noise will be heard that could suggest feedback problems.
2. Servo Drive Alarms/Trips:
Symptoms: The feeder out of control, the servo drive is showing an error code (e.g., Overload, Overvoltage, Position Error).
Diagnosis & Fix:
●Interpret the Alarm Code: Upload a servo drive manual to determine an alarm meaning. This would be the most important step.
●Check Electrical Connections: Verify the tightness (or damage) of power cables, motor cables, and encoder cables and that they are not pinched. Get adequate grounding.
●Assess Mechanical Load: Is there a jam to the feeder? Does it have too much resistance tested in the path of material? Remove obvious hindrances and provide the smooth flow of material. Examine rolls or guides and see if there are seized bearings.
●Review Parameters: Check servo tuning parameters (gains, limits) isn't changed over accidentally. As an example, consider reloading known-good parameters when recent changes are associated with faults.
●Voltage Fluctuations: Incoming power supply stability. Check incoming power supply stability. Test with a multimeter to sense a sag or overvoltage.
3. Material Slippage:
Symptoms: Material cannot be advanced because it feeds between the feed rolls, or advances sporadically. In many cases, this is accompanied by feeding inaccuracy.
Diagnosis & Fix:
●Roll Pressure: This is the suspect of the first order! Turn up the clamping pressure of the feed rolls slowly until no slippage occurs, but do not overdo it to an extent that one deforms the material.
●Roll Condition: Check rolls visually looking them out wear (particularly drive roll), knurling/grip pattern is gone or has become roughed up, or any contamination (oil, coolant or rust inhibitor). Clean or change rolls.
●Material Surface: Has the material got oily, wet or exceptionally smooth surface? It may be required to clean the material or apply rolls with a more aggressive pattern of grip.
●Roll Alignment: Make certain that the feed rolls at the top and bottom are exactly parallel and aligned along their width. Misalignment decreases good grip.
4. Unusual Noise or Vibration:
Symptoms: Grinding, clicking, humming or overly vibrating of the feeder during operations.
Diagnosis & Fix:
●Locate Source: Identify the source of the noise/vibration (motor, gearbox or rolls, guides, etc.).
●Lubrication: Gearbox oil check level/condition. consult manual on points to lubricate on bearings and guides; lubricate as need arise.
●Mechanical Wear: Check the roughness or slackness in bearings of rolls and guides, of the motor/gearbox. Check the noise of bearing. Refurbish beat bearings.
●Loose Components: Check all the mounting screws, motor ports, coupling screws and guard screws and tighten. Look to see loose pulleys or gears.
●Roller/Gear Condition: Inspect gears to see if anything is broken on their teeth, and inspect feed rolls to see if they look worn.
●Servo Tuning: Serious vibration could even be caused by improperly tuned servo loops (gains are too high). Refer to tuning notes.
5. Failure to Feed / Intermittent Feeding:
Symptoms: The feeder will not move at all per cycle, or feed intermittently.
Diagnosis & Fix:
●Check Signals: Check that the signal to start feed (out of the press or out of the controller) is getting to the feeder in a reliable way. Examine control signal wiring and connection.
●Program/Sequence: Make sure that feeder program is not corrupt. Look into proper sequencing of steps of the controller of the feeder.
●Safety Interlocks: Make sure all needed safety gates or interlocks are in place and they are closing. An improper interlock may cause a block.
●Material Detection Sensors (if used): However, make sure that material presence sensors are clean, aligned and operational. A bad or clogged sensor may cause a feed cycle not to occur.
●Power Supply: Look at fuses or circuit breakers used to supply feeder and servo drive. Make sure that there is main power.
General Troubleshooting Best Practices:
Safety First! Power should always be locked out/marked out (LOTO) prior to any internal inspection or maintenance work.
Documentation is Key: Have the feeder and servo drive manuals handy. Your roadmap would be parametrization mode and alarm codes.
Regular Maintenance: Avoid a lot of problems by carrying out regular maintenance as is usually the case: clean, lubricate, inspect and check bolt tightness.
Parameter Backup: Regularly back up the feeder controller and servo drive parameters. Restoring a known-good backup can quickly resolve configuration issues.
Start Simple: Feed Consistent Controller and servo drive parameters after regular Backups. Configuration problems can easily be remedied by restoring a known-good backup.
Step by step by expanding on these typical problems and following good maintenance procedures your servo feeders will keep running well, to spec, and reliably, to give you the maximum uptime and efficiency in your production businesses. It is very important to remember that accurate troubleshooting will lead to accurate feeding.