Examples
Examples
Try the starting example
- Pivot-to-adjustment reference radius (mm)
- 20
- Pivot-to-contact point radius (mm)
- 100
- Signed chord movement at adjustment radius (mm)
- 2
- Initial contact radius angle from horizontal (degrees)
- 0
- Ideal rigid lever rotation (degrees)
- 5.731968
- Contact-point horizontal movement (mm)
- -0.5
- Contact-point vertical movement (mm)
- 9.987492
- Signed contact-point chord travel (mm)
- 10
Try another scenario
- Pivot-to-adjustment reference radius (mm)
- 20
- Pivot-to-contact point radius (mm)
- 80
- Signed chord movement at adjustment radius (mm)
- 2
- Initial contact radius angle from horizontal (degrees)
- 0
- Ideal rigid lever rotation (degrees)
- 5.731968
- Contact-point horizontal movement (mm)
- -0.4
- Contact-point vertical movement (mm)
- 7.989994
- Signed contact-point chord travel (mm)
- 8
Calculation method
Calculation method
Ideal rigid lever rotation (degrees)
2×asin(adjustment chord/(2×adjustment radius)), with chord magnitude≤diameter.
Contact-point horizontal movement (mm)
Use rotation difference identity −2×contact radius×sin(initial+rotation/2)×sin(rotation/2).
Contact-point vertical movement (mm)
2×contact radius×cos(initial+rotation/2)×sin(rotation/2), avoiding subtractive cancellation.
Signed contact-point chord travel (mm)
Contact/adjustment radius×signed adjustment chord.
Symbols and units
- a
- Pivot-to-adjustment reference radius (mm)
- b
- Pivot-to-contact point radius (mm)
- c
- Signed chord movement at adjustment radius (mm)
- d
- Initial contact radius angle from horizontal (degrees)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- A hypothetical rigid rotation defined by chord movement at one radius. Actual lever-adjuster linkage, reach convention, free play, control clearance and suitability are not inferred or adjusted.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
OpenStax: ratios, unit rates and supplied measurement arithmetic ↗
Background reading; this does not imply endorsement or independent review of SumFizz.