During tool grinding, we sometimes encounter loud grinding noise with low grinding load, especially when a newly mounted wheel starts cutting the workpiece. 

In most cases, this is caused by excessive runout of the grinding wheel. We conducted dedicated tests for this issue:

Test machine: Daijie S500 (spindle power 6 kW)

Grinding wheel: 1A1 125×31.75×10×8, D64-MT05

Coolant: oil cooling

Workpiece material: impure alloy from Changzhou

Workpiece specs: Ø16 mm, 4 flutes, flute length 60 mm, rake angle 15°, helix angle 35°

Grinding parameters: peripheral wheel speed 18 m/s, depth of cut 4 mm, feed rate: 200 then 260.

Recorded vibration amplitudes under different grinding wheel runout values are as follows:

The recorded amplitude under different wheel runout values shows: the smaller the wheel runout after mounting, the lower the vibration. 

The wheel runout should be controlled below 0.03 mm to keep vibration within an acceptable range.

Main causes of excessive mounted wheel runout:

1. Non-standard wheel bore or out-of-round wheel;

2. Non-standard wheel arbor or shims leading to assembly error;

3. Foreign contaminants on mating surfaces during assembly of arbor and machine.

When loud vibration occurs with low grinding load, troubleshoot the above points for resolution.