I've been curious as how my drill works and now I know. Just here sharing my findings for other curious minds.
A few things that bothered me though. 1) there is extra room inside the housing for the hammer to be beefier (waste of space. the bigger the hammer the harder it hits) and 2) the hammer itself is not well balanced...well, in reality, you won't really feel it... it just feelss like just by that alone, it is loosing performance. But hey, I am a person who demands perfection. anyways, here is the video.