Print shrink compensation calculator

Isotropic linear shrinkage compensation using a supplied measured fraction.

3d-printing-shrinkage.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	commandedmm	allowancemm
	100.503	0.502513
	80.402	0.40201

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.

compensation budget0.50 mm✓ passes

BASELINE INPUTS

target100 mmshrinkage0.005

CALCULATED

commanded100.5 mm

allowance0.50251 mm

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Print shrink compensation
# Scope: Isotropic linear shrinkage compensation using a supplied measured fraction.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

target = 100 mm
shrinkage = 0.005

commanded := target/(1-shrinkage) [mm]
allowance := commanded-target [mm]

check compensation budget: allowance <= 1 mm

scenario alternative: target = 80 mm

Calculated from your source · not saved

Baseline · Baseline

compensation budget0.50 mm ✓ passes

alternative · alternative

compensation budget0.40 mm ✓ 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.

commanded: commanded = target/(1-shrinkage) [mm]
allowance: allowance = commanded-target [mm]

Original worked example

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

Given

target: 100 mm
shrinkage: 0.005

Calculated

commanded: 100.503 mm
allowance: 0.502513 mm

Assumptions and limits

Isotropic linear shrinkage compensation using a supplied measured fraction.

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: Print shrink compensation. Inputs: measured shrink by axis; target dimensions. Outputs: compensated dimensions; calibration uncertainty. Model scope: Geometry plus explicitly calibrated machine and material parameters. 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: measured shrink by axis, target dimensions
Outputs: compensated dimensions, calibration uncertainty
Modes: calculate, compare, sweep
Drawing: Part, orientation and layer preview

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