Note：the drawing does not represent the real object, just show the parameters of the pinion

Object, M0.3 plastic worm, 3 threads,  interference fit 0.7mm shaft, thickness 4.6mm, outside diameter 3mm, weight about 0.022g

thickness 4.6mm

outside diameter 3mm

Weight 0.022g 

fit 0.7mm shaft of motor

with 12/36T double teeth gear