Using double sided tape is recommended for holding the PowerHap in place. The screw holes on the body, such as Z63000Z2910Z1Z38, can be used but if you tighten to deep then can actually touch the piezo element, hindering movement.
Which driver is being used to actuate the piezos?
We recommend using piezo specific drivers such as one of the TDK eval boards also available at Digi-Key. The actual voltage that the part sees can vary if not driven properly. Actual voltage affects the displacement, force and acceleration.
Applicable part numbers
Z63000Z2910Z 1Z 2
Z63000Z2910Z 1Z 5
Z63000Z2910Z 1Z 4
Z63000Z2910Z 1Z 7
Z63000Z2910Z 1Z 1