Linear Guide Life — validation & limitations

What it calculates

• ISO 14728-1 rated-life form in kilometres for ball (exponent 3, 50 km basis) and roller (10/3, 100 km) guides — reported as the catalogue modified nominal life L10m alongside the unmodified ISO L10
• Life in operating hours from the stroke length and reciprocation frequency
• Static safety factor fS = (fH·fT·fC·C0)/P0 (ISO 14728-2) against the common LM-guide floors of 2 without vibration or impact and 5 with (brinelling guard)
• Hardness (fH), temperature (fT), contact (fC) and load/speed (fW) modifying factors
• Basis guard — states the 50/100 km reference distance so the dynamic load rating C can't be mis-plugged
• Two independent verdicts — the fatigue life and the static check are judged separately, so clearing one can never green-light the other
• Short-stroke validity check: the catalogue nominal-life formula may not apply when the stroke is under twice the LM block length
• Sizing inversions — the basic dynamic load rating the design needs, and the largest load it can carry, at your required life
• Sectioned LM-guide drawing that redraws for ball or roller elements, plus log-scale life-versus-load and life-versus-fW charts

Validation evidence — independent reference cases (2)

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.

• Modified nominal life, hours and target verdict

  Agrees

  Source: ISO 14728-1:2017 rated-life form; linear-guide maker catalogue technical section; hand derivation

  Inputs: A: roller C 60 kN, P 8 kN, fH 0.9, fT 0.9, fC 0.81, fW 1.5, stroke 400 mm, 10/min. B: ball C 35, P 5 kN, fW 1.2, target 10000 km

  Quantity	Reference value	Tolerance
  case A modified life L10m	5245.66 km	1e-9 relative
  case A life in hours	10928.5 h	1e-9 relative
  case B life vs 10000 km target	9924.77 km (fail)	1e-9 relative
  case B required C / allowable P	35.088 kN / 4.9874 kN	1e-9 relative

  tests/golden/REF-linearguide-rated-life.golden.test.ts

• Static safety factor (brinelling) and floors

  Agrees

  Source: Linear-guide maker catalogue technical section (fS = fH·fT·fC·C0/P0, guideline Table 10); ISO 14728-2 for C0; hand derivation

  Inputs: fH 0.9, fT 0.9, fC 0.81, fW 1.5 (not applied), P 8 kN; C0 80/70/12 kN, P0 10 kN; C0 80 with P0 6 kN

  Quantity	Reference value	Tolerance
  static safety factor C0 80, P0 10	5.2488 (ok on floors 2 and 5)	1e-12 relative
  static safety factor C0 70, P0 10	4.5927 (ok smooth; warning at impact floor 5)	1e-12 relative
  static safety factor C0 12, P0 10	0.78732 (fail)	1e-12 relative
  peak below running load (P0 6, P 8)	6.5610 on max(P0,P)	1e-12 relative

  tests/golden/REF-linearguide-static-safety.golden.test.ts

Limitations

Not checked by this tool

• Load distribution over the blocks from forces and moments — Per-block loads are inputs; distribute the real forces and moments over the blocks (ISO 14728) by hand or with the maker's tool
• Rail and block mounting bolts — Check the bolts for lift-off and lateral loads with /bolts
• Guide deflection, rigidity and preload class — Not computed; use the maker's rigidity data for positioning accuracy
• Mounting accuracy (rail parallelism and height difference) — Not checked; keep within the maker's permissible mounting errors
• Drive force: friction and seal resistance — Not computed; take the maker's friction and seal resistance to size the drive (/ballscrews, /motors)
• Maximum speed and acceleration of the block — Not checked; compare with the maker's limits
• Lubrication interval and contamination protection — Not assessed; follow the maker's lubrication and seal recommendations