Fable
Base frame and tooling
Old Song was the most famous craftsman in the south of the city; he could build anything—water wheels, bellows, clocks, automatic doors. If a customer could draw it, he could make it. His shop had a full set of general-purpose tools: a lathe, a drill press, measuring rulers, a calibration bench, and a cabinet of transmission components he had devised himself, with gears of every size and connecting rods of every length.
One year, the owner of a silk shop came looking to custom-build an automatic loom dedicated to silk weaving. The requirements were clear: fast shuttle changes, stable tension, automatic stop on thread breakage, and switchable patterns for thin silk and thick satin. Old Song glanced at the general components cabinet and thought it would work—the transmission chassis was very reliable, so adding silk-weaving functions on top would be enough.
In the first two months, Old Song built a prototype using general-purpose components, and the transmission part ran very smoothly. But after the weavers at the silk shop tried it, they listed a long string of problems: the silk thread knotted when changing shuttles, the warp broke when tension was high, the pattern could not switch between thin silk and thick satin, and after a thread broke the machine kept running idle. Old Song stared for a long time. What he had built was "a machine that could move," not "a loom that could weave silk well."
Old Song split the two apprentices' work. One continued maintaining the general component library—lathes, drill presses, transmission gears, the skeleton every machine needs. The other specialized in visiting the silk shop, working alongside the weavers for two months and recording the details of silk weaving one by one: when to change the shuttle, the tension tolerance of different silks, where thread breaks were most likely to occur, and the timing of pattern switches.
Two months later, Old Song added four "silk-specific parts" to the prototype machine: an automatic shuttle changer that switches automatically when tension reaches a critical point; a tension dial with five settings according to thread thickness; a break self-stop hook that brakes as soon as the thread breaks; and a pattern cam set with one preset code for thin silk and one for thick satin. With the four parts installed on the general chassis, the loom ran smoothly, and after three days of testing the weaver said it felt like a proper loom.
On delivery day, the silk shop owner asked Old Song: What exactly makes this loom special? Old Song drew a diagram: the inner ring is the general chassis—transmission, drive, calibration, the skeleton every machine needs. The outer ring is four silk-specific parts—shuttle change, tension, thread breakage, pattern—needed only for weaving silk. He said: The workshop is still the same one, but the machine is wearing a "silk work uniform."
Later a cotton cloth mill came to town, also wanting custom looms. This time Lao Song didn't build the frame from scratch—the general chassis was still the same set, just swap in a "cotton cloth work outfit": the tension dial changed to coarse cotton grading, the shuttle race widened one size to handle thick yarn, and the pattern cam set changed to two settings, plain weave and twill. Delivered in one month.
At year's end, Old Song pasted a couplet on his shop door: the upper line "One base frame travels the world," the lower line "Different tooling each finds its home." He taught his apprentice: from now on, when someone comes to order a machine, first ask whether they want a bare base frame or a complete machine fitted with tooling. A bare base frame I'll provide; a complete machine also needs tooling, rules and industry data—all three must be in place before it can go to work.