I've yet to make a successful one!
To be fair I've only tried the once.
I made a vibrating pick out of a Humming bird tooth flosser and it was rubbish, burning out after a very short time! A point which I understand is a very common occurence and which I would have learnt with less trouble by simply reading the forum!
I have plans currently to mke a new one using some Black and DEcker power scissors, in fact I may take some pictures and make an idiots guide of it for posting on the forum.