[yuhaoyang]

Mmm... I wouldn't go for the Action mechboxes personally... They're an assortment of ACM parts pieced together, and if I recall; from the various videos and internet posts on the internals, there are so many different bits that are changed frequently in the mechbox.... I think the last ones I saw used XYT gears, some other one used coal-black gears, and the sector gear in that version was basically a small ring for the axle, and connected by a few metal bits to a big ring, which was the basis for the gear teeth. If I also recall on that one the 8mm bearings were loose enough that they shook slightly in the mechbox shell sockets, and would fall out of their own accord.

But then again I've seen some people who have said certain parts of action mechboxes were good.