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Module 5 — Handoff to CAD/Mechanical

Objective: give CAD and build teams unambiguous constraints.

Prereqs: Approved concept and decision record.

Steps

  • Provide envelopes, keepouts, load cases, motion ranges, and fastener/material preferences.
  • Define tolerances for critical interfaces; note inspection datums.
  • Attach sketches/rough models and any test data.
  • Specify sensor locations, wire paths, and connector orientations.
  • Include access/maintenance notes (belt tensioning, wheel swaps, shooter cleaning).

Instructions (numbered)

  1. Compile constraints: envelopes, keepouts, loads, motion ranges, fasteners/materials.
  2. Set tolerances for critical interfaces; note inspection datums and measurement points.
  3. Specify sensor locations, wire/pneumatic paths, connector orientations.
  4. Add access/maintenance notes (tensioning, swaps, cleaning) and required tools.
  5. Attach sketches/rough CAD and test data; review with CAD/EE/ME for clarity.

Example

  • Shooter handoff: 40 in x 12 in envelope; +/- 0.03 in spacing; NEO550 encoder at motor back; belt tension slots 0.25 in; access hatch on top plate.

Best practices

  • Be explicit on tolerances and datums; avoid “builder’s choice.”
  • Call out tool access and service intervals.
  • Include sensor and wiring paths to prevent clashes later.

Common mistakes

  • Missing tolerance notes; unclear datum references.
  • No plan for maintenance access.
  • Ignoring wiring/pneumatics in the handoff.

Checklist

  • Envelopes/keepouts/loads documented
  • Tolerances and datums specified
  • Sensor and wiring paths noted
  • Access/maintenance instructions included
  • Sketches/rough CAD and test data attached

Recommended tools

  • Handoff template, tolerance table, annotated sketches/CAD screenshots.

Sample log (template)

  • Date:
  • Updates to constraints:
  • Added tolerances/datums:
  • Service/access notes:
  • Attachments:

Photos/diagrams

  • [Placeholder: annotated CAD screenshot showing envelopes and access points]

Deliverables

  • Design brief with constraints, required motions/forces, materials, and tolerances.
  • Folder with sketches/rough CAD and test notes.

Resources

  • KOP parts for packaging: firstinspires.org/robotics/frc/kit-of-parts