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A mechanical design copilot, with every tool one question away

Ask a design question, have a concept explained, check a joint or a shaft, pick a bolt or a bearing, look up a material. The AI works out which tools the question needs, runs them and explains what came back.

Built with AI coding agents; I set the safeguards and the tests.

Code on GitHubOpen source, MIT · calculators run on your machine
The bearing finder: a 6207 deep-groove ball bearing recommended, with every candidate in the space available ranked
Bearing finder

What are you working on?

Bolted jointBearingsShaftBeam or frameGear pairWelded joint
Describe the part, loads and what you need to decide…

Answers an engineer can use

A model sits between the engineer and tested tools. Two safeguards keep it honest.

It asks before it guesses

A missing load or span is asked for, not guessed.

Check an IPE 200 over 4 m.

To run the beam analysis I need these values first. They decide the result, so I won't assume them.

Point loadkN
Distributed loadkN/m

Numbers it cannot trace are flagged

A number that traces to no result and no input is shown with a warning.

Not from a calculation or your input, so unverified: 48.5.

Use M10 8.8. Preload , tightening torque .

Point at a number.

Rebuilt from the app's own messages and tests

Underneath, 415 automated test cases run on every change, against published worked examples.

Whatever the design needs next, one step away

A question, a calculation, a catalogue and a table, usually in four places, sit behind one box.

M10 8.8 through a 30 mm flange stack, 8 kN per bolt. Will the joint hold?

It picks the bolted-joint calculation, runs it and answers with the verdict first. Change the clamp length on the card and it runs again.

The bolted-joint calculator to VDI 2230: an M10 8.8 bolt passes all four checks, with the joint section drawn and labelled with its live values
Bolted joint under axial load

The AI does the joining

It chooses the tools a question needs and fills them with your numbers; when a check fails, it tries a design change before it answers.

Behind it: 28 calculators and selectors, from bolted joints to S-N fatigue, each with its diagram, checks and worked solution, and 285 standard bearing sizes (ISO dimensions, typical ratings). On day two the generated calculators were deleted for this fixed, tested library.

Is a 20 mm axle OK for 1,500 N·m bending?

  1. Plan

    Round bar, combined loading

    20 mm, 1,500 N·m: your numbers, tagged as given.

  2. Run 1

    Fails its check

    Over the stress limit at 20 mm.

  3. Follow-up

    Same load, larger diameter

    Your bending moment is kept.

  4. Run 2

    Passes

    The answer shows both runs.

Rebuilt from the app's own messages and tests
MechCopilot in 22 seconds0:22 · music, no narration

Run it

Clone it and start start.bat or ./start.sh. The tools work offline; the copilot uses your own Replicate or OpenAI key.

Code on GitHub

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