Belt Breaks

  1. Belt creases or damaged in handling
  2. Incorrect splice or improperly made
  3. Back up roll misaligned or offset in wrong direction
  4. Belt tension to low – due usually to heavy grinding load on one side of belt
  5. Sanding load to high
  6. Initial stock load on belt
  7. Trapped metal in board

Belt Creases or Folds

  1. Belt cone – shaped (different in length from side to side) If crease angle is always the same direction, mount belt so directional arrow is running backwards. If crease angle changes direction, belt is cone shaped.
  2. Tapered contact roll. Reduce to remove taper
  3. Contact roll and power roll not parallel
  4. Power roll worn (dumbbell shaped) where belts rides (center) is smaller in diameter than ends
  5. Belt tension too low

Belt Runs Off Machine

  1. Damaged or fluttering edge of belt causes tracking malfunction
  2. Tracking mechanism not adjusted properly. Belt moves slowly in one direction, but fast in opposite direction.
  3. Tapered contract roll. Redress to remove taper
  4. Belt tension too low
  5. Grinding load too high

Belt Life and Rate Of Cut Inadequate

  1. Backup roll or conveyer belt worn unevenly in center, necessitating high grinding pressure to obtain full coverage of work. Check by using very light pressure. Full coverage of work should be obtained. Correct as required.
  2. Contact roll tapered or not parallel with back up roll or conveyer belt. Grinding heavy on one side of belt.
  3. Dust collection inadequate or restricted
  4. Backup roll misaligned or not parallel with contact roll
  5. Use coarser grit size
  6. Belt commodity not well suited to material
  7. Improper storage conditions for belts

Belt Slips Under Load

  1. Belt tension too low
  2. Shock load on belt due to big variation in work thickness
  3. Plain steel rolls do not provide enough traction. Knurl or serrated surface
  4. Contact roll worn or slick – redress

Chatter Marks on Work

  1. Check for out – of – round, out – of – balance or worn bearing conditions in some rotating members of machine, or the splice, also check machine parts that oscillate, such as tracking mechanism. More common causes are contact roll, power roll drive motor, stiff splice in drive belts, coolant pump.

Wild or Deep Random Scratches in Finish

  1. Carry – over of swarf between adjust heads. Check dust collector.
  2. Loading or glazing of abrasive

Streaks in Finish

  1. Contact roll or platen wear caused by running various widths of stock without redressing
  2. Damaged or scuffed abrasive surface on belt
  3. Damaged face of contact or platen