Here is an update from PRABHURAJ.C.U on his excellent propeller build:
i made another modification to my propeller.
that is,shape of the propeller is changed,you can refer the attachment.this is done because of the following reason.
if you analyse the commercial propeller,you can see that its strength if uniform through out the propeller blade.but in our early propeller,due to the use of soda bottle plastic its strength is not uniform.this is why,while rotating the propeller end will be deflected if we provide large area.so that, i reduced area by providing elliptical shape(see the pictures).
this propeller will run smoothly than the early one.its rotating speed also improved.