cadSet/text-to-cad/skills/cad/references/cad-skillx/planning/simple-shaft-or-cylindrical-rod.planning.md

Simple Shaft Or Cylindrical Rod Planning Skill

When to use

• The request describes a single cylindrical rod, simple shaft, spacer rod, cylindrical pin, standoff-like cylinder, or shaft-like machined part.
• The body is primarily a cylinder along one axis, optionally with end holes, chamfers, simple steps, flats, slots, or threaded holes.
• The task is to generate one part, not a spindle cartridge or shaft assembly.

Do not use when

• The request describes a spindle module, motor rotor assembly, gearbox shaft assembly, bearings, seals, pulleys, keys, and fasteners together.
• The part is mainly a flange, washer, bushing, screw, bolt, or complex housing.
• The body is a hollow tube or bearing sleeve where inner/outer diameter relationship is the main design intent.

Recognition features

• Long cylindrical body with uniform or stepped diameters.
• Central axis is the dominant datum.
• Optional end chamfers, end fillets, centered threaded holes, transverse holes, flats, slots, grooves, or keyway-like cuts.
• Turning and cylindrical surfaces dominate; milling may appear for flats, slots, or keyways.

Core invariants

• Establish one main shaft axis and overall length first.
• Use extrude for a uniform simple cylinder; use revolve for stepped diameters, grooves, shoulders, tapers, or turned profiles.
• Keep all coaxial diameter changes, end holes, and grooves aligned to the shaft axis.
• Treat holes, slots, flats, keyways, and threads as secondary features.
• Do not invent bearings, couplings, gears, or housings unless requested.

Parameter roles

• length defines the axial span.
• diameter defines a simple rod.
• step_diameters, step_lengths, shoulder_positions, and groove_width define turned features.
• end_hole_diameter, thread_size, and thread_depth define centered end holes.
• flat_width, slot_width, slot_depth, and keyway_length define milled secondary features.
• chamfer_distance and fillet_radius define edge finishing.

Construction sequence

1. Define the shaft axis and overall length.
2. For a simple rod, sketch a circle and extrude along the axis.
3. For stepped or shouldered shafts, sketch the half-profile and revolve it around the axis.
4. Add centered end holes, threaded holes, grooves, flats, slots, or keyways as secondary cuts.
5. Keep secondary features referenced to the shaft axis or end-face datums.
6. Finish with end chamfers, shoulder fillets, and small edge breaks.

Common failures

• Generating a spindle or bearing assembly when only a shaft/rod part was requested.
• Creating off-axis end holes.
• Using multiple separate bodies for diameter steps instead of one coherent solid.
• Treating a threaded shaft, bolt, or screw as the same as a plain shaft without preserving thread/head differences.
• Adding arbitrary decorative grooves that were not requested.

Evidence summary

• Latest run evidence: 107 accepted planning insights matched shaft, rod, cylinder, and stepped-shaft construction.
• Strong repeated names include plan_stepped_shaft, simple_cylinder_extrusion, stepped_shaft_construction, cylindrical_rod_planning, and plan_revolve_shaft_profile.
• Frequent operations in the latest run: Extrusion, Revolution, Cut, RevCut, HoleWzd, Chamfer, Fillet.
• Source model examples: 000166, 001957, 040325, 069352, 080683, 100698, 112997, 144199, 148300, 160726, 172872, 210853, 218803, 225038, 232675, 239358.
• Source: CAD-SkillX offline review of SCAD58 descriptions, STEP summaries, and SolidWorks feature evidence.

Retrieval metadata

Triggers:

• cylindrical rod
• simple shaft
• shaft
• rod
• pin
• standoff

Secondary triggers:

• stepped shaft
• end hole
• threaded end
• shaft groove
• keyway
• chamfered ends

Operation triggers:

• extrude circle
• revolve shaft profile
• cut end hole
• cut slot
• chamfer ends

Exclusions:

• spindle assembly
• bearing assembly
• flange
• washer
• bolt head
• gear