Roll Forming Machine Troubleshooting: Causes & Fixes

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Problems on this page:

Profile twist or bow Flare at the cut ends Edge wave or buckling Cut lengths out of tolerance Scratches or marks on the profile Strip wandering at the entry Burrs and wear at the cut-off Long coil changes and threading

Profile twist or bow

Hits OEE: Quality

Symptoms: The formed profile twists along its length or bows up, down or sideways.

Roll gaps uneven between the two sides

Set the roll gap on both sides of each station with feeler gauges to the setup sheet.

Stations not aligned to the line centre

Check the station alignment with a line or laser and correct the shafts that are out.

Coil with camber or uneven stress

Check the coil before running and adjust the straightener at the entry.

Too much forming in one station

Spread the bending over more stations as the tooling designer intended.

Prevention: Roll gaps recorded at setup and checked when the profile changes.

Flare at the cut ends

Hits OEE: Quality

Symptoms: The ends of each cut length open out or close in compared with the middle of the profile.

Stress released at the cut

Adjust the last forming stations or the straightener to balance the stress.

Over-bending in the final stations

Reduce the overbend in the last passes.

Cut-off die not supporting the profile

Check the cut-off die shape and clearance.

Prevention: End flare measured on the first parts of each coil.

Edge wave or buckling

Hits OEE: Quality

Symptoms: The flange edges or flat areas show waves or buckles.

Strip edge stretched too much

Check the forming sequence and the roll gaps at the stations that form the edge.

Strip thickness above the setup value

Measure the strip and set the gaps for the actual thickness.

Roll gaps too tight

Open the gaps to the setup sheet values.

Material harder than specified

Check the material certificate and test the coil.

Prevention: Strip thickness and hardness checked at each coil change.

Cut lengths out of tolerance

Hits OEE: Quality

Symptoms: Lengths vary from part to part or drift during a coil.

Encoder wheel slipping on the strip

Clean the wheel and check its pressure on the strip.

Flying cut-off acceleration settings wrong

Tune the cut-off motion for the line speed.

Strip slipping in the rolls

Check the drive roll pressure and the roll surfaces.

Length compensation not set

Measure parts and set the length correction in the controller.

Prevention: First-off length check at each coil and every hour.

Scratches or marks on the profile

Hits OEE: Quality

Symptoms: Lines, scuffs or marks appear on visible faces of the profile.

Damaged roll surface

Polish or regrind the damaged rolls.

Debris on the rolls

Clean the rolls and keep the strip clean at the entry.

Speed mismatch between stations

Check the roll diameters and drive ratios.

Lubrication missing where needed

Use the forming lubricant the tooling maker recommends.

Prevention: Roll condition inspected at each tooling change.

Strip wandering at the entry

Hits OEE: Availability

Symptoms: The strip moves sideways into the first stations and the line has to stop.

Entry guides set too wide

Set the guides to the strip width.

Coil camber

Check the coil and straighten it before the entry.

Decoiler brake or tension uneven

Adjust the decoiler tension.

Prevention: Entry guide setting on the changeover sheet.

Burrs and wear at the cut-off

Hits OEE: Quality

Symptoms: Cut ends have burrs or distortion that grows during the run.

Cut-off blade worn

Sharpen or replace the blade on a fixed schedule.

Blade clearance wrong for the material

Set the clearance for the thickness and grade.

Cut-off die loose

Check the die fixing and alignment.

Prevention: Blade hits counted and changes logged.

Long coil changes and threading

Hits OEE: Availability

Symptoms: Each coil change takes a long time and the first parts are scrap.

Coil not prepared before the stop

Prepare the next coil, its leading end and the paperwork before the old coil runs out.

Threading done by hand at slow speed

Use a coil car and a threading routine.

No splice or end joining

Consider an end joiner on long runs of the same material.

Prevention: Coil change time measured and reviewed weekly.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: press brake · stamping press · slitter rewinder · hydraulic system · gearbox

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Recurring roll forming machine stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.

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Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover