Learn formbar

From zero to printed part.

Seven short lessons with real screenshots. Every step shows the key to press, and every key is also in the command palette (Space).

Lesson 0 · 1 min

The 60-second tour

One window, one mode. Sketching and modelling happen in the same view. Hover or tap the numbers.

1
Menu
New, open, save, export, settings.
2
Tool rail
Sketch, Shapes, Extrude, Revolve, Push/Pull, Edge, Move, Pattern, Combine. Shortcut letters on the right.
3
Hint card
Always tells you what the current tool wants next.
4
View cube
Click a face or corner to look from there.
5
View rail
Fit, switch projection, change render style.
6
Items & History
Your bodies on top, every step you took below.
7
Undo, redo, status
Undo always works. The status line says what just happened.
8
Theme & settings
Light, dark, grid and snapping.

Mouse: middle-drag orbits, right-drag pans, wheel zooms, F fits everything. Left-click picks a face or edge, Shift-click adds to the selection.

Lesson 1 · 5 min

Your first part: an L-bracket

A 60 × 40 mm L-bracket with two holes, a rounded bend and bevelled outer edges. Seven steps, and you will have used most of formbar.

1
Draw the L
Press S to sketch on the ground plane, then L for lines. Click the corners: 0,0 → 60,0 → 60,8 → 8,8 → 8,40 → 0,40, and back to the start. The shape closes itself.
SL
2
Pull it up 40 mm
Press E. formbar leaves the sketch and grabs the profile. Move the mouse up to preview, type 40, press Enter.
E40Enter
3
Sketch on the upright
Click the inside face of the upright to select it, then press S. The view turns to face it squarely.
S
4
Add two holes
Press C and draw two circles, 6 mm across. Press Esc twice to leave the sketch.
CEsc
5
Cut them through
Click one hole, Shift-click the other, press E and push into the part. Pushing in cuts automatically. Type 8 and press Enter.
⇧ clickE8
6
Round the inside bend
Click the inner edge of the bend. Pick Fillet on the little toolbar that appears (or press B), type 3, press Enter.
B3
7
Bevel the outside and export
Shift-click the outer vertical edges, choose Chamfer, type 1. Then ≡ → Export STL or 3MF. Done: a printable bracket.
⇧ click1

Lesson 2 · 4 min

Sketches that stay put

Constraints and dimensions turn a rough drawing into an exact one. When a sketch reaches 0 DOF (degrees of freedom), nothing can move by accident.

1
Type the size as you draw
Press R, click the origin, then type 80, Tab, 50, Enter. A typed rectangle on the origin is fully locked straight away.
RTab
2
Drop in four holes
Press C, click a centre, type 5 for the diameter. Repeat in each corner. The centres are still free to move.
C
3
Pin them with dimensions
Press D, click a hole and then an edge, type 6. Do both directions for each hole. The status bar turns green at 0 DOF.
D
4
Change your mind
Click the 80 pill and type 100. The plate grows, and the holes stay 6 mm from the edges because you said so.

Lesson 3 · 2 min

Push, pull, round

You don't always need a sketch. Drop a shape and shape it with your hands: faces push and pull, edges round and bevel.

1
Drop a box, pull an edge
Shift+B drops a box: click, type 40, Tab, 30, Tab, 20. Then drag a top edge outward and it becomes a fillet.
⇧B
2
Push the face
Drag the top face up (or press P with it selected). The fillet rides along. Ctrl snaps to 0.5 mm.
P
3
Done, and still editable
Every gesture lands in the history as a normal step, so you can change it later.

Lesson 4 · 2 min

Turned parts with Revolve

Pins, knobs, vases and wheels: draw half the profile and spin it.

1
Draw half the section
Sketch the outline of half the part, with one edge on the centre line.
SL
2
Revolve
Click Revolve on the left rail. formbar guesses the centre line; press X to try the next line if it guessed wrong.
X
3
Enter, and it's solid
Type an angle for a partial turn, or press Enter for a full 360°.
Enter

Lesson 5 · 2 min

Patterns: one hole, twelve holes

Model one feature, then repeat it around an axis or along a line.

1
Pattern around the bore
Select the hole and press Shift+P. Click the bore's wall to use it as the axis, then drag or type a count.
⇧P
2
Change the count any time
Double-click the Pattern step in History and type 12. Up and Down add or remove one copy.
↑↓
3
Or in a straight line
Press L (or the Linear pill) for a row: count 4, Tab, spacing 15.
LTab

Lesson 6 · 3 min

History and parameters

Everything you do is a step you can go back to. Change an early size and the rest of the part follows.

1
Open History
The Items card on the right lists your bodies, with History underneath. Each row is a step.
2
Double-click to edit
Double-click Extrude and type 50. The holes, fillet and chamfer all follow. Enter keeps it, Esc puts it back.
EnterEsc
3
Safe when it can't work
Ask for something impossible, like a 40 mm fillet, and the step turns red with the reason. The last good part stays.
4
Name your numbers
Add a parameter like depth = 6 and type =depth into any value. Change it in one place, the part updates everywhere.
=

Lesson 7 · 3 min

Let an AI agent do the boring bit

formbar includes an MCP server. Any AI agent that speaks MCP can build real formbar parts: sketches with constraints, extrudes, fillets, patterns and parameters. You get an editable file back, not a mesh.

1
Add formbar to your agent
formbar's MCP server starts with the formbar-mcp command. Add it as an MCP server in your agent's settings. It talks over stdio and runs headless, so nothing pops up on screen.
```
{
  "mcpServers": {
    "formbar": {
      "command": "formbar-mcp"
    }
  }
}
```

Ask for the tedious part

Be specific about sizes and what it is for. Ask for named parameters so you can tweak them later, and ask it to check the part is printable.

Use formbar to model a spur gear: module 2,
24 teeth, 15 mm thick, 8 mm bore with a
2 mm keyway. Make "teeth" a parameter.
Check it is printable, export an STL and
save the .formbar file.

3
Open it and make it yours
Open the .formbar file. Every step is in the history, every number is editable. Change teeth from 24 to 30 and the gear rebuilds. Now do the fun part: the hub, the spokes, the feel.

What an agent can do: documents and parameters, sketches with every constraint type, extrude, revolve, push/pull, fillet, chamfer, primitives, booleans, move, patterns, editing and suppressing history, measuring, rendering a picture to look at its own work, checking printability, and exporting STL, 3MF, STEP, DXF and SVG. Edits are atomic: anything that breaks the model is rolled back with the reason.

Cheat sheet

Keyboard shortcuts

Single letters never fire while you are typing in a field. In sketch mode some letters change meaning: F is Fillet, P is Project, S is Spline.

Everywhere

S: Sketch (on the selected face)
E: Extrude
LRCA: Line, rectangle, circle, arc
D: Dimension
M: Move body
F: Fit view
Space: Command palette
Esc: Cancel / clear selection
Ctrl+Z: Undo

Body mode

P: Push/pull a face
B: Fillet / chamfer an edge
⇧B⇧C⇧S: Box, cylinder, sphere
⇧O⇧T: Cone, torus
⇧P: Pattern

Sketch mode

SN: Spline, polygon
OI: Offset, mirror
FH: Fillet, chamfer
TK: Trim, split
P: Project body edges
X: Toggle construction
G: Snap to grid

While a tool runs

0–9: Type a value
Tab: Next value
10,5@10,025<30: Type a point (sketch)
ACN: Extrude: add, cut, new body
c2: Edge: chamfer 2 mm
XYZ: Move along an axis
Enter: Commit

From zero to printed part.

Draw the L

Pull it up 40 mm

Sketch on the upright

Add two holes

Cut them through

Round the inside bend

Bevel the outside and export

Type the size as you draw

Drop in four holes

Pin them with dimensions

Change your mind

Drop a box, pull an edge

Push the face

Done, and still editable

Draw half the section

Revolve

Enter, and it's solid

Pattern around the bore

Change the count any time

Or in a straight line

Open History

Double-click to edit

Safe when it can't work

Name your numbers

Add formbar to your agent

Ask for the tedious part

Open it and make it yours

Everywhere

Body mode

Sketch mode

While a tool runs