Skip to main content

Mechanical Standards

Version: v2025.0
Owner: Mechanical Lead
Last Updated: 2025-11-27
Reviewed: No
Deviations Allowed: Yes (with approval)

Why: consistency, serviceability, and reliability under FRC abuse. Use these standards as guardrails and checklists.

Spec table (template)​

  • Construction style (box/plate), tube sizes, wall thickness
  • Shaft standard, bearing type, belt/chain rules
  • Preferred ratios and wheel types for drive/intake/shooter
  • Fasteners: sizes, threadlocker rules, torque ranges

Visual example​

  • Add annotated photo/render of a compliant subsystem.

Common failure modes​

  • Loose hardware, belt slip, chain derails, bent shafts, deflection under load.
  • No tensioning, poor tool access, overhung loads on shafts, thin gussets flexing.

Lessons learned​

  • What we keep from past seasons; what we avoid.

Sources

  • AndyMark: andymark.com
  • REV: revrobotics.com
  • WCP: wcproducts.com
  • Thrifty Bot: thethriftybot.com
  • McMaster (hardware/pneumatics): mcmaster.com

Instructions (numbered)​

  1. Pick construction style (box tube vs plate) and set default tube sizes/wall thickness.
  2. Standardize shafts/bearings and belt/chain pitch; define center-distance and tensioning methods.
  3. Select preferred fasteners and torque/threadlocker rules; define when to use nylocks vs Loctite.
  4. Define drivetrain/mechanism ratio ranges and wheel types per use-case.
  5. Require CAD reviews for tool access, tensioning, and stiffness before release.

Best practices​

  • Build in tensioning (slots/turnbuckles) for belts/chains; avoid fixed C-C unless proven.
  • Keep overhung loads low; support shafts near loads; use standoffs/gussets for stiffness.
  • Leave tool access; check serviceability in CAD.
  • Use consistent fastener sizes to reduce tool changes; mark torque-critical joints.

Common mistakes​

  • No allowance for tensioning; chain/belt derailments.
  • Thin plates/gussets that flex; overhung loads bending shafts.
  • Buried fasteners with no tool access; skipping threadlocker/nylocks where needed.

Checklist​

  • Tube/plate thickness per standard
  • Shaft/bearing and belt/chain per standard pitch
  • Tensioning designed in and accessible
  • Tool access verified in CAD
  • Fastener size/torque/threadlocker noted
  • Stiffness/bracing adequate; overhung loads minimized
  • Calibrated torque wrench/driver, threadlocker, belt/chain tools, feeler gauges, calipers, Loctite guide.

Sample log (template)​

  • Date:
  • Subsystem:
  • Deviations from standard (if any):
  • Checks performed:
  • Issues/mitigations:

Photos/diagrams​

  • [Placeholder: annotated subsystem showing tensioning, fasteners, and access paths]

Deviations​

  • Any deviation from these standards requires lead/mentor approval and a documented rationale. Record deviations in the sample log.

Version & ownership​

  • Owner: Mechanical lead/mentor
  • Review cadence: at least pre-season and mid-season

See also:

��� Reference the Glossary for definitions of common terms and constraints.