Unstable measurements of the ring-and-belt balancer may occur while correcting the workpiece imbalance. The reasons are as follows:
1. The drive rod of vibration sensor of ring balancer is loose or vibration is blocked.

2. Loose plug or socket of vibration sensor wire of ring balancer results in blocked signal.

3. The top force of the axial stop frame of the ring-belt balancer is too great.
4. Rotor shaft with balancing machine is bent or runs around and its finish is poor.
5. Roller bearing ball wear or roller circumference smoothness, circle runout out of tolerance.