cell(phone) vibration

[hahaho]

Hi, i want to vibrate the cell(phone) steadly

so, i used this code.

import viz
viz.go()
viz.phys.enable()
cell = viz.add('phone.3ds')
cell.setPosition(0.11510615050792694, 1.6993328332901001, 1.0478180646896362)
cell.setEuler([0,-80,0])
cell.collideSphere()
ANCHOR_POS = (0.11510615050792694, 1.6993328332901001, 0.1478180646896362)
joint = viz.phys.addHingeJoint(cell,None,pos=ANCHOR_POS,ax is0=[0,0,1])


but the cell's vibration is more and more largely ...
later , the cell is Out of sight.