Cam & Follower — validation & limitations

What it calculates

• Full 360° displacement, velocity and acceleration profiles for five motion laws: SHM, cycloidal, parabolic, 3-4-5 and 4-5-6-7 polynomial
• Side-by-side motion law comparison charts — instantly see how acceleration peaks differ between laws
• Pressure angle and minimum radius of curvature with automatic undercut detection for roller followers
• Knife, roller and flat follower types with eccentricity support
• Follower spring design — liftoff and bounce-risk analysis with minimum preload recommendation
• Hertz contact stress for roller and flat-face followers with safety factor against allowable
• Live polar cam-profile diagram and animated pressure-angle chart with 30° and 45° warning bands

Validation evidence — independent reference cases (1)

Each case runs the tool's engine on a worked example whose values come from a published source or a hand derivation from the cited equations, and an automated regression test asserts the engine against those values within the stated tolerance. "Conservative" means the engine is known to sit on the safe side of the reference and the test asserts that side. Sources are cited; their text is not reproduced.

• Maximum follower pressure angle (radial, offset, knife follower)

  Agrees

  Source: Norton, Design of Machinery, ch. 8 pressure angle of a translating follower (equation number not re-verified); cycloidal and 3-4-5 SVAJ closed forms

  Inputs: A: roller rb 40, rr 10, h 30, cycloidal 120 deg; B: same with eps 10 mm; C: knife rb 50, h 20, 3-4-5 over 60 deg

  Quantity	Reference value	Tolerance
  phi_max, case A	24.2566 deg (OK)	0.005 deg
  phi_max, case B (return flank)	31.9232 deg (CHECK)	0.005 deg
  phi_max, case C	31.1429 deg (CHECK)	0.005 deg

  tests/golden/REF-cams-pressure-angle.golden.test.ts

Limitations

Not checked by this tool

• Follower roller bearing life — Size the cam follower from the peak contact force with the roller maker's dynamic rating
• Contact fatigue life and wear of the cam track — Contact stress is screened against an allowable only; check pitting life and lubrication with the material data
• Camshaft deflection, torsional wind-up and its bearings — A rigid cam is assumed; model the camshaft in /shaft
• Follower-train elasticity and residual vibration — Rigid follower; lift-off is a spring-mass screen — use a multi-mass dynamic model at high speed
• Return-spring fatigue and surge — Size the spring in /springs (fatigue and surge) for the cam's stroke and speed
• Process load, gravity and guide friction at the follower — The computed contact force is spring + inertia only; enter a larger total contact force that includes them