CALCULATORS / PNEUMATICS, HYDRAULICS AND VACUUM

Vacuum suction-cup sizing calculator

Static suction area at supplied pressure difference; leakage and dynamics omitted.

pneumatics-vacuum-cup.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	grossForceN	workingForceN
	62.8319	31.4159
	40.2124	20.1062

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.

holding target31.42 N✓ passes

BASELINE INPUTS

diameter40 mmdifference50 kPafactor2

CALCULATED

grossForce62.832 N

workingForce31.416 N

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Vacuum suction-cup sizing
# Scope: Static suction area at supplied pressure difference; leakage and dynamics omitted.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

diameter = 40 mm
difference = 50 kPa
factor = 2

grossForce := difference*pi*diameter^2/4 [N]
workingForce := grossForce/factor [N]

check holding target: workingForce >= 20 N

scenario alternative: diameter = 32 mm

Calculated from your source · not saved

Baseline · Baseline

holding target31.42 N ✓ passes

alternative · alternative

holding target20.11 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.

gross force: grossForce = difference*pi*diameter^2/4 [N]
working force: workingForce = grossForce/factor [N]

Original worked example

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

Given

diameter: 40 mm
difference: 50 kPa
factor: 2

Calculated

gross force: 62.8319 N
working force: 31.4159 N

Assumptions and limits

Static suction area at supplied pressure difference; leakage and dynamics omitted.

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: Vacuum suction-cup sizing. Inputs: pressure difference; cup area; load; leakage factor. Outputs: holding force; cup count estimate. Model scope: Pressure, flow and actuator geometry with compressibility assumptions. 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: pressure difference, cup area, load, leakage factor
Outputs: holding force, cup count estimate
Modes: calculate, compare, sweep
Drawing: Actuator and circuit diagram

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