i read on this thread about doing this - but NOW i see and it makes sense. this is the best tip i've rec'd. - no, it's the one about glueing the binding, no, it's the one..... gosh they're ALL good. it's like a gold mine of info. - better than any 'how to' book.
i think the first thread didn't specify the tip from a 'mechanical' pencil - or else i didn't catch that part. a ball point pen tip isn't very small. i have another brand of mechanical pencil here in the office, 7mm and it works too - very small tip.