cdsl-cad/backend/agent/skills/cad-engine/references/part-skills/source/functional/mounting-plate-hole-layout.functional.md

Mounting Plate Hole Layout Functional Skill

When to use

• A plate or base block needs holes, slots, counterbores, countersinks, or threaded holes positioned from datum edges or centerlines.
• The layout is rectangular, row-based, symmetric, mirrored, or grid-like rather than circular around a flange axis.
• The hole layout controls mounting, alignment, adjustment, or fastening.

Do not use when

• Holes are evenly spaced around a circular bolt circle on a flange.
• The holes are decorative, random, or not functionally related.
• The main operation is a bearing bore or central shaft seat rather than a mounting-hole layout.

Recognition features

• Flat planar top face or side face used as the hole placement plane.
• Edge margins, centerline offsets, pitch values, or symmetric pairs.
• Repeated hole groups, slots, threaded holes, clearance holes, counterbores, countersinks, or dowel holes.
• SolidWorks evidence often appears as HoleWzd, Cut, LPattern, MirrorPattern, and Chamfer.

Core invariants

• Define plate datums before hole placement.
• Keep hole centers constrained to margins, pitch, and symmetry instead of free coordinates.
• Select the hole type from fastening function, not from appearance.
• Pattern the cut or hole feature after the seed feature is correct.
• Preserve minimum material around holes and between holes.

Parameter roles

• datum_edge_x, datum_edge_y, and centerline define references.
• edge_margin_x, edge_margin_y, pitch_x, pitch_y, row_count, and column_count define repeated layouts.
• hole_diameter, thread_size, fit, and end_condition define the hole itself.
• counterbore_diameter, counterbore_depth, countersink_angle, and slot_length define fastener seating or adjustability.

Construction sequence

1. Select the plate face and define construction centerlines or edge-offset dimensions.
2. Create one seed hole or one seed hole group using HoleWzd or a through cut.
3. Use linear pattern for rows/grids and mirror for symmetric pairs.
4. Use slots when the design requires adjustment rather than fixed bolt location.
5. Add counterbore, countersink, or thread data to the seed hole before patterning where possible.
6. Add chamfers and deburring features after the functional holes are complete.

Common failures

• Converting counterbored/threaded/countersunk holes into plain cylinders.
• Patterning sketch circles instead of the actual cut or hole feature.
• Mixing flange bolt-circle logic into rectangular plate layouts.
• Missing datum margins, causing holes to float.
• Placing slots too close to edges or other holes.

Evidence summary

• Current library evidence: 207 reviewed SCAD58 plate-like models.
• Latest run evidence: high-frequency accepted insights for hole wizard use, standard hole types, symmetric hole placement, linear hole patterns, mirror patterns, slots, and edge chamfers.
• Frequent operations in the latest run: HoleWzd, Cut, LinearPattern, MirrorPattern, Chamfer.
• Source: CAD-SkillX offline review of SCAD58 descriptions, STEP summaries, and SolidWorks feature evidence.

Retrieval metadata

Triggers:

• mounting plate hole layout
• base plate hole pattern
• rectangular hole grid
• symmetric mounting holes

Secondary triggers:

• edge margin
• linear pitch
• counterbored holes
• threaded holes
• slots
• dowel holes

Operation triggers:

• hole wizard
• linear pattern
• mirror holes
• cut through holes
• counterbore
• countersink

Exclusions:

• flange bolt circle
• bearing bore
• random decorative holes