This calculator converts selected shaft speed to angular speed, evaluates radial inertial-force magnitude mω²r for one selected rotating mass, and reports a disclosed algebraic 2F/k displacement proxy. It does not predict the calibration or sleeve travel of a real speed indicator.
Speed Indicator · Selected Radial-Force Ledger
Explore selected angular-speed and radial-force arithmetic without treating the displacement proxy or squared-speed index as an instrument calibration.
Equation Used
- Mass is represented as a point at the selected fixed radius.
- Speed is steady for the scalar radial-force calculation.
- The selected spring rate is used only in the disclosed algebraic 2Fr/k proxy.
- The 3000 rpm value is a normalization reference only.
- Link geometry, force projection, preload, changing radius, gravity, friction, stops, gearing, calibration and safety are excluded.
Former sleeve-lift and dial-deflection claims are narrowed to an algebraic 2Fr/k proxy and a squared-speed reference index.
Selected radial-force reference
The animation shows an illustrative symmetric flyweight and dial layout. Exact values are confined to angular speed, one-mass radial force, the stated 2F/k proxy, and a squared-speed index relative to 3000 rpm.
What the calculator determines
Select shaft speed, one rotating mass, its radius and a comparison spring rate. The calculator reports ω, mω²r, 2mω²r/k, and 100(N/3000)².
Selected scalar ledger
ω=2πN/60; Fr=mω²r; xproxy=2Fr/k; speed index=100(N/3000)².
Selected-input example
At 3000 rpm, m=20 g and r=20 mm, one-mass radial force is about 39.48 N. With k=5 N/mm, the disclosed algebraic 2F/k proxy is about 15.79 mm and the squared-speed index is 100%.
Force ledger, not instrument calibration
A real flyweight mechanism requires link geometry and force projection, changing radius, spring preload, effective rates, gravity, friction, stops and a calibrated transmission to the pointer. Therefore the proxy is not literal sleeve lift and the index is not a dial calibration.
Questions
Why is 2Fr/k only a proxy?
The two radial forces do not generally act directly along the sleeve axis; link angles and reactions determine axial force and motion.
Is the percentage a calibrated dial reading?
No. It is only a squared-speed index normalized to 3000 rpm and may exceed 100%.
References & Further Reading
- Wikipedia contributors. Tachometer. Wikipedia
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