It could be due to two reasons. One, Vibro/Dynamics manufactures vibration isolators as opposed to simple machinery mounts. Our goal is to provide the best ISOLATION possible while keeping machinery motion to an acceptable level. A larger area isolator is USUALLY a softer isolator. Due to the larger area, greater isolator deflection is possible without over stressing the isolator’s elastomeric element. OVERSTRESSING causes leveling instability (due to elastomeric creep) and the higher stress on the foundation. 

Two, a larger isolator may have been recommended to provide BETTER support coverage of the MACHINE foot. The isolator support housing should span the foot gussets.

It could be due to two reasons. One, Vibro/Dynamics manufactures vibration isolators as opposed to simple machinery mounts. Our goal is to provide the best isolation possible while keeping machinery motion to an acceptable level. A larger area isolator is usually a softer isolator. Due to the larger area, greater isolator deflection is possible without over stressing the isolator’s elastomeric element. Overstressing causes leveling instability (due to elastomeric creep) and the higher stress on the foundation. 

Two, a larger isolator may have been recommended to provide better support coverage of the machine foot. The isolator support housing should span the foot gussets.