BIZOMAT MAKEOS · Mechanics
Centrifugal Force on a Rotating Mass
What outward force does this rotating mass exert?
Centrifugal force, acceleration in g and tangential speed of a mass rotating at a radius, for clamps, counterweights and attachments.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Rotating mass | kg | Mass of the part, weight or jaw that rotates. |
| Radius to centre of mass | mm | Distance from the axis to the part’s centre of mass. |
| Speed | rpm | Highest speed the part will run at. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Rotating mass
- What it is
- The mass of the rotating part whose outward pull you want, such as a chuck jaw, counterweight or blade.
- Units and format
- Enter a number in kg: kilograms. The form accepts 0.000001 kg to 1000000 kg. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2 kg as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The force rises in proportion to the mass.
- Get it right
- Include the screws and fittings that move with the part.
What this means: Radius to centre of mass
- What it is
- The distance from the rotation axis to the part’s own centre of mass, not to its outer edge.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 150 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The force rises in proportion to the radius.
- Get it right
- Use the radius, not the diameter of the circle the part runs on.
What this means: Speed
- What it is
- The rotational speed of the part, normally the highest speed it will run at in service.
- Units and format
- Enter a number in rpm: revolutions per minute. The form accepts 0.000001 rpm to 1000000 rpm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1500 rpm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The force rises with the square of the speed, so doubling the speed gives four times the force.
- Get it right
- Use the maximum possible speed, including any overspeed, not the usual running speed.
Method and formulas
- ω = 2πn ÷ 60; F = m ω² r (r in metres).
- Acceleration = ω² r; in g = ω² r ÷ 9.80665.
- Example: 2 kg at 150 mm and 1500 rpm pulls outward with 7,402.2 N (377.41 g).
Limitations
- Rigid body at steady speed; the effect of the part deflecting outward is not included.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check clamping of fixture parts and counterweights on a spindle
- Estimate loads on rotor attachments
- Assess chuck jaw force loss at speed
Who it is for
- Design engineers
- Maintenance engineers
- Technicians
What you get
- Centrifugal force
- Acceleration in g
- Tangential speed
Interpreting the result
- Compare the force with the clamp, bolt or jaw holding capacity, including your safety factor.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 187–190. Topic reference; no source tables or recommended settings are reproduced.
Learn the Concepts Behind This Tool
These BIZOMAT Library readings explain the method this tool uses, with worked examples.
Method explained here · BIZOMAT original book
Centrifugal loads on discs and hammers
In Whirling Shafts by the Numbers
What it covers: The loads that speed itself puts on a rotor: centrifugal force on hammers and pins, hoop stress in rotating discs, why both rise with the square of speed, and a mill run 20% fast on a drive.
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