Stop feeding and shut the machine down safely if vibration is new, severe or increasing. Isolate all power sources and wait for the rotor to stop before inspection. Do not keep running to see whether it settles down.
Check the installation first
Look for loose anchors, cracked supports, shifted mounts or contact with surrounding structures. A qualified technician should check foundation integrity and tightening requirements before a restart.
Check belts, pulleys and guards
Misalignment, a damaged belt, a loose pulley or rubbing guards can create vibration. Inspect only with the drive isolated. Use the prescribed alignment and tension procedure; excessive tension can damage bearings.
Inspect rotating assemblies
Bearing damage, an unbalanced drum, a bent shaft or internal contact requires a competent repairer. Do not run the mill with a suspected rotating-part failure. Do not weld or rebalance a rotating component without a qualified assessment.
After a repair
Refit all covers and guards, remove tools and follow the specific restart procedure. Observe from a safe position. Stop again if abnormal vibration or mechanical noise remains.
Parts and replacement decisions
Record bearing markings, shaft dimensions and pulley details before ordering. If structural damage is extensive or vibration recurs after correct repairs, compare the total repair cost with replacement.