A carpenter’s boy, meant apprentice, and in those days it was a way for young men to acquire skills in various trades. Apprentices were formally bound to Master craftsmen for several years, without pay but provided with board and lodging. Upon release from his service to his master, an apprentice would have become a highly skilled craftsman so we shouldn’t dismiss Karl’s comment as implying the wheel was easy to make, I think he was suggesting that the concept was easy to understand.
His first wheel at Gera, was only four inches thick which leaves little room for the mechanisms to operate. But although I did not concern myself with trying to fit everything within the limited space of four inches, in the process of avoiding mechanical interference I found a solution, which was to apply a slight double bend in the levers which altered their path at a particular point along their length thus avoiding the collision.
One more thing, as a consequence of comments in the preceding blog, I would just point out the difficulties described above would not show up in a sim, so although it might show a successful build, the detail for the build would still require considerable experimentation, trial and error.