A couple of days ago, I bought a clearance‑sale BK‑01. Upon receiving it, I found the build quality utterly appalling—far inferior even to many contemporary children’s toys. The fishbone component, in particular, is assembled from two snap‑fit halves, with an extremely pronounced gap along the rail section. So I decided to print my own version of the fishbone.
The exterior design was done rather casually, without referencing any specific prototype.
The mounting method follows the original manufacturer’s approach: simply use the factory‑provided fishbone retaining ring, screws, and nuts. This is also the key distinction between my print and the versions already available online.