napkin.
Menu

CALCULATORS / LEAD SCREWS AND LINEAR STAGES

Screw buckling load calculator

Euler pin-ended solid circular screw column.

screws-buckling.napkin / editable
✓ checks pass

SCENARIO COMPARISON

Compare the numbers.

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

Scenarioinertiamm^4criticalNfactor
1017.888036.838.03683
416.9223291.883.29188

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.

buckling factor target8.04 ✓ passes

BASELINE INPUTS

CALCULATED

inertia1017.9 mm^4
critical8036.8 N
factor8.0368

Edits change the baseline source.

Calculated from your source · not saved
Baseline · Baseline
buckling factor target8.04 ✓ passes
alternative · alternative
buckling factor target3.29 ✓ 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.

inertia
inertia = pi*diameter^4/64 [mm^4]
critical
critical = pi^2*modulus*inertia/length^2 [N]
factor
factor = critical/load

Original worked example

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

Given

diameter
12 mm
length
0.5 m
modulus
200 GPa
load
1000 N

Calculated

inertia
1017.88 mm^4
critical
8036.83 N
factor
8.03683

Assumptions and limits

Euler pin-ended solid circular screw column.

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: Screw buckling load. Inputs: root diameter; unsupported length; end conditions. Outputs: Euler buckling estimate. Model scope: Screw kinematics with efficiency and load 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: root diameter, unsupported length, end conditions
  • Outputs: Euler buckling estimate
  • Modes: calculate, compare, sweep
  • Drawing: Linear-stage animation

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

More in lead screws and linear stages