print-details

Printable detail

Hand-modelled detail was the main source of print-gate failures in Spark Make: in one run 64 of 111 component rounds failed check_thickness or check_overhang, on thin tapers at the edges of decorative cones and bands, overhangs under discs and rims, and broken solids from overlapping trims. Each feature here is built so it cannot make those: it refuses a size below the wiki's limits, grows a root into the host, gives every face that would look down a 52 deg slope, ends in a step or a chamfer, and returns one valid solid or raises PrintLimitError naming the limit and its wiki page.

Install (Workshop Manager)

The library must live inside the CAD project, so the sealed project still builds when the host copies it elsewhere. Copy it once, with the shared files, before spawning any Component Worker:

"$WORKSHOP_PYTHON" .agents/skills/print-details/scripts/print_details.py --install <cad-project>

It writes <cad-project>/features/print_details.py, byte for byte, and refuses to overwrite a copy with other bytes. It is a standard element, like a stdpart gear: never edit the copy. Tell each worker it is there.

Use (Component Worker)

from build123d import Box, Pos
from features import print_details

pd = print_details.Details(nozzle=0.4)      # the run's nozzle; up=(0, 0, 1)

def gen_step():
    body = Pos(0, 0, 10) * Box(30, 30, 20)
    body = pd.rivets(body, pd.along((-10, -15, 18), (10, -15, 18), 6), d=2.4, h=0.8)
    body = pd.panel(body, (0, -15, 10), width=8, height=8, depth=0.8, arch="lancet")
    body = pd.band(body, pd.segment((-14, -15, 3), (14, -15, 3)), width=2.0, height=1.0)
    return body

Each call takes the host solid and returns the new one. A point is on the host's surface; the feature stands on the nearest face along its outward normal. up is the print direction in your generator's coordinates: +Z when gen_step() returns the part in its print stance, as it should.