Cable management

Cable management is in v1 scope deliberately. A desk or a media unit that cannot get a cable from the back of a device to a socket is a design failure that no other woodworking tool checks for, and the geometry to check it — a panel with a hole in it — is already in the model.

The PTH- path rules are not built yet. The codes are reserved in the registry and no rule implements them, so nothing currently checks that a cable route is continuous. These entries are the numbers to design to in the meantime, and the edge-distance and feature-within-blank checks do run against the holes you cut for them.

Grommets

Id	Nominal Ø	Depth	Ring Ø	Clear bore
fixtures.grommet.40	40	22	46	34
fixtures.grommet.60	60	24	68	52

The 40 has a cap; the 60 has a brush insert, which keeps dust out and still passes a plug.

clearBore is not the hole you drill

This is the field that exists to prevent one specific mistake. The drilled hole for a grommet.40 is 40 mm. The usable opening once the trim ring is fitted is 34 mm — the cap costs about 6 mm.

Size a bundle against the drilled hole and it will not fit — a 40 mm grommet passes a 34 mm bundle, not a 40 mm one.

Machining

Id	Through part	Receiving part
grommet.40	40 mm hole, through	—
grommet.60	60 mm hole, through	—

Rules

Id	Min edge	Min end	Min spacing	Panel thickness
grommet.40	28	28	60	12 – 22
grommet.60	40	40	90	12 – 24

Both a minimum and a maximum panel thickness. The maximum is real: the body is 22 mm long, so it will not reach through a 25 mm top, and the grommet simply will not seat. The minimum is what the clip needs to grab.

A 40 mm grommet also needs 28 mm of panel around it. Putting one 20 mm from a back edge splits the panel, and the edge-distance check catches it.

Cable tie mounts

Id	Base	Screw bore
fixtures.cable_tie_mount.20	20 mm square × 8	2.5 mm × 12 deep

Min edge	Min end	Min engagement	Min spacing
14	20	10	100

Screwed or adhesive. End grain is warn — the mount is carrying a cable bundle in shear and wants face grain under it.

100 mm minimum spacing is about the bundle, not the wood: tie mounts closer than that do not let the cable bend between them.

Using them

A grommet does not join two parts, so there is no second part to mate to. Cut its hole as a hole feature on the panel, sized from the table above:

parts:
  - id: desk_top
    material: top_stock
    grain: length
    blank: { length: 1600, width: 700, thickness: 22 }
    features:
      - kind: hole
        id: cable_exit
        on: top
        diameter: 60          # fixtures.grommet.60 — drilled size, not clear bore
        through: true
        at: { u: 1400, v: 120 }

This is the one place the catalogue’s numbers are yours to transcribe rather than the compiler’s to apply, because a grommet is not a fastener between two parts. Check three things against the table:

• Panel thickness is inside the entry’s range — a 22 mm top is at the limit of the grommet.40 and fine for the grommet.60.
• The hole is at least the minimum edge distance from every edge. 120 mm from the back edge of a 700 mm top clears the grommet.60’s 40 mm easily; 20 mm would not, and GEO-003 measures a hole at its rim, not its centre.
• The bundle fits the clear bore, not the drilled diameter.

The hole itself is checked — that it lands on the board and keeps its edge distance. What is not yet checked is whether the route it belongs to actually goes anywhere, which is what the PTH- rules will do.

Assembly

Both grommets fit with no tool, and the step hint is after_finish — they go in once the panel is oiled or lacquered, because finishing around a fitted grommet is miserable. The tie mounts are after_finish too.

Those hints reach the assembly steps when a fixture is declared on a joint. Since a grommet is authored as a feature today, put it in the part’s note: instead.

Procurement

Id	Pack sizes	Unit cost
grommet.40	1 · 10	2.10
grommet.60	1 · 10	3.40
cable_tie_mount.20	20 · 50	0.18