Bevels & Rabbets#

Stopped mouldings on any edge, straight or vertical

Names: bevel rabbet moulding trim

When to use#

• A flat slope across an edge at a chosen angle (a bevelled shelf front, a hopper side's mitred edge): bevel angle=. For a 45° corner break use chamfer.
• A step cut into an edge, including a vertical edge (the back rabbet on a standing carcass side, a notch at a shelf's front corner, a lipped drawer front's ends): rabbet face= edge=.
• A profile (ovolo, cove, ogee, ...) that starts and ends part-way along an edge: moulding ... stopped=#true.
• trim aligns a raked end to a plane fixed in world space (reference=world) or in the nearest enclosing assembly's own frame (reference=assembly, #458).

Syntax#

bevel  angle=<deg 1..<90> [depth=<mm>] { edges <edge>... }      // or:
bevel  face=<face> edge=<adjacent face> angle=<deg> [depth=<mm>]
rabbet width=<mm> depth=<mm> { edges <edge>... }                // or:
rabbet face=<face> edge=<adjacent face> width=<mm> depth=<mm>
       [stopped=#true start=<mm> run_length=<mm>]
moulding section=<ovolo|cove|ogee|thumbnail|half_round|cockbead> size=<mm>
       [stopped=#true start=<mm> run_length=<mm> stop=square|ramp] { edges <edge>... }

• face= is the face the cut goes into and the angle or width is measured on; edge= is an adjacent face (not face, not its opposite). Faces are pos_x neg_x pos_y neg_y pos_z neg_z. Use face=/edge= or { edges }, never both.
• Bevel depth= defaults to the whole thickness across face; the facet is depth / tan(angle) wide on face.
• Rabbet width is measured on face from edge; depth goes into face.
• Stops: start= defaults to 10 mm in; start=0.0 reaches the end of the edge; omit run_length= to run out through the far end. bevel takes stop=square|ramp|lambs_tongue, moulding takes square|ramp, rabbet is square-ended only.

Example#

project name="Bevel and rabbet" units=mm schema_version=1 {
    materials { material Oak type=hardwood }

    component Side {
        stock Oak 20.0 300.0 600.0
        // Back rabbet on the standing side: the vertical edge where pos_x meets pos_y.
        rabbet face=pos_x edge=pos_y width=18.0 depth=6.0
    }

    component Shelf {
        stock Oak 400.0 250.0 20.0
        // A 35 degree bevel across the front edge, the whole thickness.
        bevel angle=35.0 {
            edges top_s
        }
        // A cove that stops 50mm in from each end of the back edge.
        moulding section=cove size=5.0 stopped=#true start=50.0 run_length=300.0 {
            edges top_n
        }
    }

    assembly Piece {
        part Side instance=Side { pos x=0.0 y=0.0 z=0.0 }
        part Shelf instance=Shelf { pos x=40.0 y=0.0 z=0.0 }
    }
}

Pitfalls and diagnostics#

• angle outside [1, 90) is ww::build::bad_value, a missing angle is a missing-property error. A facet wider than the face, a depth thicker than the board, face= without edge= (error) or with { edges } (skip, "not both"), non-adjacent faces ("adjacent"), and stop= without stopped= are skips naming the cause: the built part simply has no such cut, so read the skipped list, not just the green tick.
• upright_* in { edges } is skipped for bevel and rabbet. Use face=/edge=.
• stop=ramp on a rabbet is a skip ("square"); stop=lambs_tongue is for chamfer and bevel only.
• A stopped moulding is a 32-layer staircase: it never removes more than the true section and falls under 7% short of its volume. Do not expect a smooth curve at the run's ends.
• A through rabbet face= edge= that a dovetail socket or other join opens into is understood by the join (it is lowered as a housing on face); write it, rather than a groove at the edge of the face.
• trim reference=assembly is built (#458): the nearest enclosing instance=-placed assembly's own frame, identity (same as reference=world) when there is none. A reference= naming neither world nor assembly is a named skip.

See also#

• docs/KDL_AUTHORING.md section 7, "Bevel, and a rabbet on any edge" and "Moulding profiles"
• docs/rfc/0143-bevel-and-stopped-mouldings.md, docs/adr/0024-bevel-rabbet-stopped-mouldings.md
• RFC-0051 (rabbet on any edge), RFC-0126 (mouldings), RFC-0025 (stopped chamfers), RFC-0024 (trim)
• Examples: examples/bedside_cabinet.kdl, examples/welsh_dresser.kdl, examples/wall_shelf.kdl, examples/dining_chair.kdl; docs/styles/models/bevel.kdl

Names#

Every name this page declares, how the example library uses it, and the shortest real use.

bevel#

feature; node in 6 of 116 examples (16 uses).

Shortest real use, from jacobean_joined_chest.kdl:

bevel face=pos_y edge=pos_z angle=10.0 depth=bevel_depth

rabbet#

feature; node in 24 of 116 examples (56 uses).

Shortest real use, from tall_white_cutout_cabinet.kdl:

rabbet face=pos_x edge=pos_y width=back_th depth=rd

moulding#

feature; node in 18 of 116 examples (36 uses); value in 2 of 116 examples (4 uses).

Shortest real use, from farmhouse_harvest_table.kdl:

moulding section=thumbnail size=6.0 {
    edges top_s
}

trim#

feature; node in 5 of 116 examples (7 uses); value in 1 of 116 examples (1 uses).

Shortest real use, from mid_century_credenza.kdl:

trim reference=world normal=pos_z at=floor_z {
    faces pos_x
}

Related terms#

• Bevel
• Rabbet