nurb · describe the part, print the part

4 min read Original article ↗

design 3d-printable parts by talking

no CAD software · no tutorials · no failed prints

nurb gives the AI you already talk to real CAD skills. Say what you need, watch it take shape live, hit print.

// 01  the whole idea

You say it. It appears. This one is live.

Make an adapter that connects my shop vac hose to the dust port on my table saw

Done: Ø57.6 → Ø35.0 · 74 mm, all checks clean. Drag the sliders to tweak it.

drag to orbit · scroll to zoom

This demo is a lightweight imitation; the real thing runs a full engineering CAD kernel. The STL you download here is real and printable, though. Go print it.

// 02  the conversation

Revisions are sentences too.

Look at the part, say what's wrong with it. CAD software never opens.

It wobbles on the vac hose, way too loose

Measure the outside of the hose end for me. Calipers if you have them, a careful ruler works.

57.4

Bored the cuff to 57.6 mm, a snug push fit. Checks still clean, and the stl button has your file.

measures, never guessesIt asks for the real dimension instead of inventing one.

millimeters, not menusEvery dimension becomes a slider. Automatically.

your tweaks stickDrag, save. Your AI keeps designing from your numbers.

files that just workSTL for your slicer. STEP if a machine shop asks.

// 03  how it works

You talk. It models. Physics checks the work.

Three things happen. You only do the first.

you

Say what you need. It asks for measurements instead of guessing.

your browser

hose_adapter rebuilt

Ø57.6 → Ø35.0 · 74 mm

0.3 s · your view stays put

Watch it take shape. Live, and the camera never jumps.

the check

walls thick enough everywhere

bed grip plenty of plate contact

steep slope bore shoulder at 52°, stretch the taper

Failures get caught before your printer finds them.

// 04  the safety net

Nine hours of printing. Checked before it starts.

Calibrated on parts that really printed, and it knows which printer you own.

steep slopesoverhangs that sag or peel away as they print

thin wallssections finer than your nozzle can lay down

tiny detailsfeatures that smear instead of printing

mid-air startsmaterial with nothing underneath to land on

top-heavy shapestall parts that tip over before they finish

long reachesjuts that sag under their own weight, or snap in use

loose piecesa part that quietly came apart into two

the wrong sizetoo big for the machine you actually own

// 05  the real world

Point your phone at it.

Some shapes don't come from numbers. Sweep the thing for ten seconds and your part gets built against its real contour.

the chat

I can't measure this, it's all curves

Scan it with your phone instead. Ten seconds, then drop the file here.

It offers. You never have to know this was possible.

your phone

free scanning app

sweep the siding · 10 s

export the file

Sweep it. No special hardware, no turntable, no rig.

your browser

300 × 250 mm

5 mm step between courses

bracket hugs the profile

It reads the shape. In millimeters, then builds to it.

// 06  more than one part

It opens the lid before your printer does.

A door can build clean, check clean, print beautifully, and still not open. Parts that work together get tested together.

a box for the shelf, with a lid that flips up

Both parts are modelled. Swinging the hinge, it jams at 84° on the shelf above.

can it clear?

Moved the pivot forward 3 mm. It now opens to 110° and stops there on purpose, so the lid rests instead of falling back.

tested as a setParts that mate get built and checked together, not one at a time.

the whole swingIt runs the hinge through its full travel and names the angle where it hits.

the wall countsDescribe the shelf or the machine it mounts to and that gets included.

drag it openThe joint angle is a slider. Move it and the whole assembly moves.

// 07  get started

One download and a sentence.

The Mac app is the whole thing in one window. The command line works with Claude Code, Cursor, Codex, Copilot, and friends.

  1. Download for Apple silicon

    Your projects, your AI, and the live viewer side by side. It sets everything up the first time you open it and updates itself. Download for Intel Macs.

    Rather work in the terminal? One paste installs nurb and teaches your AI how printable parts are designed:

    $curl -fsSL https://nurb.dev/install.sh | sh

  2. Make an adapter that connects my shop vac hose to the dust port on my table saw

    Your AI models it, checks it, and sends you a link to watch. Looks right? Print.