Documentation
Getting started with ProtoJoint
Open the editor in Chrome or Edge. There is nothing to install and no account to create: it starts with an empty design, and you can sketch, extrude and export right away.
What do I need?
A computer with a recent Chrome or Edge, on Linux, ChromeOS, macOS or Windows; other current browsers may work, but Chrome and Edge are what it is tested in. The first visit downloads about 13 MB, and the browser keeps it for later visits. A mouse with a wheel you can press makes moving the view much easier than a touchpad.
Do I need an account?
No. Modeling, importing, exporting and saving all work without one. An account is needed only for the AI features: Eleph, the built-in AI design assistant, and connecting an AI app such as Claude Desktop (see AI). During the beta, accounts are by invitation.
Where are my designs saved?
In two places, both on your computer:
- The design you are working on is saved automatically in the browser’s own storage. Reload the page, or come back next week on the same computer and browser, and it is still there.
- Save (Ctrl+S) writes the design to a file ending in
.protojoint.json; Open reads one back. Keep these files: they are your backup and the way to move a design to another computer.
Nothing is uploaded unless you use an AI feature, which sends the AI what it needs to answer you.
How do I make my first part?
- Press N (or click New sketch) and click the XY plane. The view turns to face it.
- Press R for a rectangle and click where its first corner goes. Type
60, press Tab, type40, and click again: the rectangle is placed with those sizes, and they become its dimensions. - Click Finish sketch.
- Press E to extrude. The rectangle is picked for you when it is the only profile; type
10in the distance box and press Enter. - Press F for a fillet, click the four vertical edges, set the radius to
5and press Enter.
You now have a 60 × 40 × 10 mm plate with rounded corners. To change its size later, double-click the sketch on the timeline at the bottom, double-click a dimension, type the new value and finish the sketch: the plate and its fillets follow.
How do I move the view?
| To | Do this |
|---|---|
| Pan | Drag with the middle button (press the wheel) |
| Orbit | Shift and drag with the middle button, or Alt and drag with the left button |
| Zoom | Turn the wheel; it zooms towards the cursor |
| Fit everything | Double-click the middle button |
| Standard views | Click the view cube at the top right, or press 1 top, 2 front, 3 right, 0 isometric |
How do I find a command?
Press S for the toolbox and type part of a command’s name. The right mouse button opens the marking menu: eight common commands around the cursor, and a menu below for whatever is under it. Drag in a direction and let go to run a command without looking at the menu. F1 lists every shortcut.
The keys follow the defaults most CAD users already know: E extrude, Q press pull, H hole, F fillet, M move, J joint, I measure, V show or hide the selection. Ctrl+Z and Ctrl+Y undo and redo. You can give any command your own key in the toolbox.
What units does it use?
Each design has its own length unit, chosen next to the design’s name in the header: millimetres, centimetres, metres or inches. A number without a unit is in that unit, and you can type 0.45in, 12.7 mm or 3/8" into any field to have it converted. Angles are in degrees unless you write rad. Changing the unit does not change the model, only how its sizes are shown.
Can I watch a design being built?
Yes. Press S, type “replay” and choose Replay a demo. ProtoJoint builds the cycloidal reducer example step by step, every tool and value as it was first made, with a bar to pause, speed up or stop it. It is a quick way to see how the tools fit together.
Where next?
Sketches and constraints explains how to draw precisely, Features covers everything that makes and changes solids, and Parameters shows how to drive a design from a few numbers.