Linkage mechanical advantage calculator

Virtual-work ratio from supplied small input/output displacements.

linkages-mechanical-advantage.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	advantage	outputForceN
	4	32
	3.2	25.6

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

force target32.00 N✓ passes

BASELINE INPUTS

inputTravel20 mmoutputTravel5 mmeffort10 Nefficiency0.8

CALCULATED

advantage4

outputForce32 N

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Linkage mechanical advantage
# Scope: Virtual-work ratio from supplied small input/output displacements.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

inputTravel = 20 mm
outputTravel = 5 mm
effort = 10 N
efficiency = 0.8

advantage := inputTravel/outputTravel
outputForce := effort*advantage*efficiency [N]

check force target: outputForce >= 25 N

scenario alternative: inputTravel = 16 mm

Calculated from your source · not saved

Baseline · Baseline

force target32.00 N ✓ passes

alternative · alternative

force target25.60 N ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

advantage: advantage = inputTravel/outputTravel
output force: outputForce = effort*advantage*efficiency [N]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

input travel: 20 mm
output travel: 5 mm
effort: 10 N
efficiency: 0.8

Calculated

advantage: 4
output force: 32 N

Assumptions and limits

Virtual-work ratio from supplied small input/output displacements.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Linkage mechanical advantage. Inputs: mechanism pose; applied force or torque. Outputs: instantaneous force and motion ratio. Model scope: Planar rigid-link geometry with explicit joints and branches. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: mechanism pose, applied force or torque
Outputs: instantaneous force and motion ratio
Modes: calculate, compare, sweep
Drawing: Interactive linkage

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS