How Do I Maintain Stackers and Runout Tables on a Roll Forming Line?

Surface scratching (especially pre-painted coil)

Why Stacker & Runout Maintenance Matters

Poorly maintained handling systems cause:

• Surface scratching (especially pre-painted coil)

• Edge denting

• Panel bowing

• Stacker misalignment

• Product jams

• Inconsistent stacking

• Slow production

Even if the profile is perfect, poor handling ruins it.

1️⃣ Daily Cleaning (Most Important)

Metal dust and debris cause scratching and jams.

Daily:

• ✔ Clean runout rollers
• ✔ Remove metal shavings
• ✔ Wipe transfer belts
• ✔ Clear stacker tray
• ✔ Check drop zones

Pre-painted material requires extra cleanliness.

2️⃣ Inspect Rollers & Bearings

Runout tables rely on smooth rollers.

Weekly:

• ✔ Check roller rotation
• ✔ Inspect for flat spots
• ✔ Check bearing play
• ✔ Replace seized bearings
• ✔ Confirm alignment

Seized rollers drag panels and scratch coatings.

3️⃣ Maintain Roller Alignment

Misaligned rollers cause:

• Panel skewing

• Uneven stacking

• Side edge damage

Monthly:

• ✔ Verify straightness across table
• ✔ Check levelness
• ✔ Confirm side rails are square

Even small misalignment becomes visible on long panels.

4️⃣ Inspect Belt Conveyors (If Equipped)

If using belts:

• ✔ Check tension
• ✔ Inspect for wear
• ✔ Check tracking
• ✔ Replace frayed belts
• ✔ Ensure smooth speed control

Loose belts cause jerking and panel marking.

5️⃣ Check Stacker Lift Mechanism

Automatic stackers rely on:

• Hydraulic lift

• Chain drive

• Servo lift

Inspect weekly:

• ✔ Lift smoothness
• ✔ Cylinder leaks
• ✔ Chain tension
• ✔ Alignment of stack arms

Uneven lift causes stack tilt and product damage.

6️⃣ Monitor Drop Height

Excessive drop height causes:

• Panel deformation

• Edge damage

• Surface impact marks

Adjust:

• ✔ Stack height controls
• ✔ Lift synchronization
• ✔ Sensor positioning

Keep drop height minimal.

7️⃣ Inspect Sensors & Limit Switches

Stackers depend on accurate detection.

Weekly:

• ✔ Test photo-eyes
• ✔ Confirm limit switch function
• ✔ Check wiring
• ✔ Clean sensor lenses

Sensor failure causes mis-timed stacking.

8️⃣ Lubricate Moving Components

Lubricate:

• ✔ Chain drives
• ✔ Lift guides
• ✔ Bearings
• ✔ Pivot arms

Follow manufacturer interval (typically weekly to monthly).

Avoid over-greasing near panel contact areas.

9️⃣ Check Structural Stability

Vibration loosens:

• ✔ Frame bolts
• ✔ Guide rails
• ✔ Support brackets

Monthly torque check prevents alignment drift.

🔟 Prevent Surface Damage on Pre-Painted Coil

For coated materials:

• ✔ Use rubber-coated rollers
• ✔ Avoid sharp edges
• ✔ Replace worn polyurethane sleeves
• ✔ Keep all contact surfaces smooth

Handling damage is often mistaken for forming defects.

11️⃣ Maintain Proper Speed Synchronization

Stacker speed must match line speed.

If not synchronized:

• Panels collide

• Panels shift

• Stack becomes uneven

Verify speed matching regularly.

12️⃣ Monitor Panel Tracking

Watch for:

• Panel drifting sideways

• Uneven stacking

• End-of-line twisting

These often indicate roller misalignment.

Recommended Inspection Schedule

Daily (heavy production):

• Clean rollers and table

• Visual check of lift and sensors

Weekly:

• Inspect bearings

• Check alignment

• Lubricate moving parts

Monthly:

• Torque check

• Verify structural alignment

• Inspect belts and lift system

Quarterly:

• Full mechanical inspection

• Replace worn rollers

• Check hydraulic/servo calibration

Most Common Real-World Problems

• 1️⃣ Dirty rollers scratching pre-painted panels
• 2️⃣ Seized runout bearings causing drag
• 3️⃣ Uneven stacker lift causing panel tilt
• 4️⃣ Poor speed synchronization
• 5️⃣ Excessive drop height

Most issues are preventable with simple routine checks.

Final Expert Insight

To maintain stackers and runout tables:

• ✔ Clean daily
• ✔ Inspect rollers weekly
• ✔ Verify alignment monthly
• ✔ Lubricate moving parts properly
• ✔ Control drop height
• ✔ Maintain sensor accuracy
• ✔ Synchronize speed

The most common cause of finished panel damage is neglected runout rollers combined with poor cleaning discipline.

Stable handling protects:

• Product appearance

• Coating integrity

• Customer satisfaction

• Production efficiency

• Profit margins