CALCULATORS / MOLDING, CASTING AND TOOLING

Molded-part cooling-time estimate calculator

Reference-calibrated squared wall-thickness cooling scale; not a full transient thermal solve.

molding-cooling-time.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	durations
	45
	36

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.

cooling time budget45.00 s✓ passes

BASELINE INPUTS

referenceTime20 sreferenceThickness2 mmthickness3 mm

CALCULATED

duration45 s

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Molded-part cooling-time estimate
# Scope: Reference-calibrated squared wall-thickness cooling scale; not a full transient thermal solve.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

referenceTime = 20 s
referenceThickness = 2 mm
thickness = 3 mm

duration := referenceTime*(thickness/referenceThickness)^2 [s]

check cooling time budget: duration <= 60 s

scenario alternative: referenceTime = 16 s

Calculated from your source · not saved

Baseline · Baseline

cooling time budget45.00 s ✓ passes

alternative · alternative

cooling time budget36.00 s ✓ 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.

duration: duration = referenceTime*(thickness/referenceThickness)^2 [s]

Original worked example

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

Given

reference time: 20 s
reference thickness: 2 mm
thickness: 3 mm

Calculated

duration: 45 s

Assumptions and limits

Reference-calibrated squared wall-thickness cooling scale; not a full transient thermal solve.

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: Molded-part cooling-time estimate. Inputs: wall thickness; diffusivity; melt/mold/ejection temperatures. Outputs: conditional cooling time. Model scope: Early process estimates with material and supplier data. 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: wall thickness, diffusivity, melt/mold/ejection temperatures
Outputs: conditional cooling time
Modes: calculate, compare, sweep
Drawing: Part, cavity and runner diagram

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