01Gravity, line shaft or motorised roller
Gravity sections need a slope and a person or gravity to move goods. Belt or chain driven rollers push everything together. Motorised drive rollers power one short zone each and stop zone by zone, so goods queue without pressure.
02Roller pitch and diameter
Your shortest item must rest on at least three rollers, or it tips and snags. Shorter pitch means more rollers per metre and a higher price, so check the pitch quoted against your smallest carton.
03Accumulation logic
Zero-pressure zones with a sensor per zone keep cartons apart. Minimum-pressure lines let them touch. Ask how many zones and sensors the quote includes.
04Curves, merges and diverts
Tapered rollers on curves keep cartons square. Merges and diverts need their own drives and controls, and they are where the cost and the jams concentrate.
05Roller build
Galvanised, stainless or plastic sleeves, bearing type and shaft retention. Wet, cold or washdown areas need the right roller, not a painted one.