* a homemade light that looks homemade is crap, no matter how bright it is.
* a bike light that is this protected from the elements is crap also
the whole build part is nice and done very good, but the description that poor guy had was several years old and (even at that time) bad.
It is easy: when You see a real heatsink, the descrition is outdated. Makes more problems than it solves, makes it difficult to protect the whole thing from the elements, fins are useless as they are not in the airflow, ...
... looking froward to his following 2nd version.
When he has seen the actual "standard way of building" by using simply the head of an existing host light.
THAT then will be very nice, I am sure.