Conveyor belt runs off — how to track a belt
Symptom
The belt runs to one side at the tail, at the head, only when loaded or only when empty, rubs the frame, or jumps sideways once per revolution.
Likely causes
- Build-up of material on the tail pulley or return idlers.
- Off-centre loading at the chute.
- Frame, idler stations or pulleys not square to the belt.
- Splice not square, so the belt jumps once per revolution.
- Seized or dirty training idler, low tension, side wind, or an object stuck in the structure.
Most likely and cheapest to check first.
Checks
- Lock out. Clean the tail pulley, return idlers and return belt first.
- Watch where material lands on the belt with the conveyor running loaded, from the walkway.
- Check the frame is level and square; check each idler station and pulley is square.
- Check the splice with a square, and the take-up tension.
Fix
- Clean, fit or repair the V-plough, and correct the loading chute before adjusting anything else.
- Square the frame and pulleys.
- Train the belt in small steps, starting where it first runs off, moving one idler at a time a few millimetres.
- Re-make a crooked splice.
- Fit belt sway switches so the belt stops before it destroys its edges.
Stop the equipment if
The belt is rubbing the frame or the edges are being cut.
Parts you may need
The golden rule
Most mistracking is caused by dirt, loading or a crooked structure, not by the idlers. Adjusting idlers to hide a dirty tail pulley only moves the problem. Clean and check first, then train.
DANGERMost conveyor accidents happen at the head and tail pulleys during cleaning or adjusting. Never scrape a pulley, turn an idler by hand or reach between idlers with the belt running. A shovel near a running pulley is pulled in with the hand holding it.
FIELD TIPWalk the belt from the walkway every day and look for idlers that do not turn. A seized idler grooves the belt and starts mistracking.
⚠ Every check inside a machine starts with full lockout. Safety disclaimer