Calculations

Shafts

• Shaft strength calculation (DIN 743)

  Fatigue and static safety of a shaft to DIN 743-1/-2:2012 at every shoulder, keyway, groove and press fit, with notch, size, surface and mean stress factors.

  • DIN 743-1:2012
  • DIN 743-2:2012
  • DIN 743 Beiblatt 1:2024
• Shaft strength to the FKM guideline

  Shaft fatigue and static strength to the FKM guideline (7th edition): utilisation aBK and aSK at every notch, finite life and Miner damage over a duty cycle.

  • FKM guideline, 7th edition (2020)
• Shaft deflection calculation

  Deflection, slope, bending moment, von Mises stress and bearing reactions of a stepped shaft in both planes, by Timoshenko beam elements, with pass/fail limits.

• Shaft critical speed calculation

  Bending critical speeds and mode shapes of a shaft, gyroscopic forward and backward whirl, the Campbell diagram, unbalance response, torsional and axial modes.

  • ISO 21940-11

Rolling bearings

• Bearing life calculation (ISO 281)

  Bearing rating life to ISO 281:2007: dynamic load rating C, basic life L10, modified life with aISO, κ, eC and Cu, reliability factor a1 and system life.

  • ISO 281:2007
  • ISO/TR 1281-1:2008
  • ISO/TR 1281-2:2008
  • ISO/TS 16281:2008
• Bearing load distribution (ISO/TS 16281)

  Internal load distribution of rolling bearings to ISO/TS 16281:2008: load on every element, contact angles, contact stress, clearance, tilt and roller laminae.

  • ISO/TS 16281:2008
  • DIN 26281:2010
  • ISO 281:2007
  • ISO/TR 1281-1:2008
• Bearing static safety and static load rating (ISO 76)

  Static load rating C0 and static safety s0 of rolling bearings to ISO 76:2006, from Hertz contact at the real groove radii and the solved load on every element.

  • ISO 76:2006
  • DIN ISO 76:2009

Gears and drives

• Gear calculation (ISO 6336)

  Rate spur and helical gear pairs by ISO 6336 method B: geometry, load factors, pitting and tooth root safety, scuffing by ISO/TS 6336-20 and the mesh loss.

  • ISO 6336-1:2006
  • ISO 6336-2:2019
  • ISO 6336-3:2019
  • ISO 6336-5:2016
  • ISO 6336-6
  • ISO/TS 6336-20:2022
  • ISO/TR 13989-2:2000
  • ISO/TR 14179-1
• Bevel gear calculation (ISO 10300)

  Rate straight, spiral and Zerol bevel gears by ISO 10300-1 and -2: cone geometry, shaft forces, virtual gears, load factors, pitting and tooth root safety.

  • ISO 10300-1:2014
  • ISO 10300-2:2014
  • ISO 6336-3:2019
• Worm gear calculation (DIN 3996)

  Rate a steel worm on a bronze or cast iron wheel by DIN 3996 method C: efficiency and losses, wear, pitting, worn tooth root, deflection and oil temperature.

  • DIN 3996:2012
• Plastic gear calculation (VDI 2736)

  Rate POM, PA66, PA66 GF30 or PEEK gears by VDI 2736-2: tooth temperatures from the heat balance, root and flank safety at temperature, wear and tip deformation.

  • VDI 2736-2
• Belt and chain drive calculation

  Belt and chain drives between two shafts: V-belt, flat belt, timing belt or roller chain. Strand tensions, pretension and slip, shaft load and its direction.

Joints, fits and contacts

• Bolted joint calculation (VDI 2230)

  Single-bolt joints after VDI 2230-1:2015, steps R0 to R13: preload, tightening torque, load factor, embedding and yield, fatigue, pressure and slip safeties.

  • VDI 2230-1:2015
  • ISO 898-1:2013
• ISO 286 limits and fits calculator

  ISO 286 limit deviations of a hole and shaft pair up to 500 mm: tolerance zones, least and largest clearance or interference, and the fit type.

  • ISO 286-1:2010
  • ISO 286-2:2010
• Press fit and shrink fit calculation (DIN 7190)

  Elastic press fit of a hub on a shaft after DIN 7190-1: contact pressure, torque and axial capacity, hub and shaft stresses, shrink temperature, speed.

  • DIN 7190-1:2017
  • ISO 286-1:2010
  • ISO 286-2:2010
• Parallel key and spline calculation (DIN 6892, DIN 5480)

  Parallel keys after DIN 6892 with DIN 6885-1 sizes, DIN 5480 and ISO 4156 splines: flank pressure on shaft, hub and key, tooth shear, capacity.

  • DIN 6892
  • DIN 6885-1:1968
  • DIN 5480-1:2006
  • DIN 5480-2:2006
  • ISO 4156
• Weld calculation (EN 1993-1-8, EN 1993-1-9)

  Fillet and butt weld groups in one plane: throat stresses and utilisation by the directional or simplified method of EN 1993-1-8, fatigue to EN 1993-1-9.

  • EN 1993-1-8:2005
  • EN 1993-1-9:2005
  • EN 1993-1-1:2005
• Hertzian contact stress calculator

  Hertz contact of two elastic bodies: contact ellipse or line, peak pressure, approach and stiffness, and the shear and von Mises stress below the surface.

  • ISO/TS 16281:2008
  • ISO 76:2006

Linear motion, springs and housings

• Linear guide life calculation (ISO 14728)

  Size profile rail linear guides by ISO 14728: table load shared over the carriages, equivalent loads with moments, rating life in km and hours, static safety.

  • ISO 14728-1
  • ISO 14728-2
• Ball screw calculation (ISO 3408)

  Rate a ball screw by ISO 3408-5 over a load spectrum: rating life with nut preload, static safety, critical speed, buckling, d·n, efficiency and drive torque.

  • ISO 3408-5:2006
  • ISO 3408-4:2006
• Helical spring calculation (EN 13906)

  Helical compression, extension and torsion springs after EN 13906: rate, forces, stresses, solid length, buckling, hooks, initial tension and fatigue.

  • EN 13906-1:2013
  • EN 13906-2
  • EN 13906-3
  • EN 10270-1
  • EN 10270-3
• Bearing housing stiffness (finite elements)

  Radial and tilt stiffness of a bearing seat in a housing wall by finite elements, and how it changes shaft deflection, bearing loads and critical speeds.

Across the whole project

Beside the calculations: the views and the report that take every module of a project together.

• Assembly in 3D

  Every shaft where its gear pairs and drives put it, the gears in mesh, the bearings in their seats, coloured by their checks. Click a part to open it.

• Overview

  One page for the project: checks passed and failed, the ones closest to their limits, what changed since the last save, power flow and parts list.

• Calculation reports

  Sections in your order, document control and sign-off, changes since an earlier revision, page numbers, PDF and Word, and templates of your own.