MakerCAD

Free CAD software by Makers for Makers.

Read more about MakerCAD and why I made it on my blog

The Vision

Build a software based CAD suite that provides:

1. Relative geometry construction (build features relative to what you've already built)
2. Parametric modeling (model based on modifiable parameters)
3. Collaboration on modeling (git pull requests)
4. Version control (also via git)

Long term goals:

1. Build a code editor UI (a la OpenSCAD)
2. Build a UI for non-coders

Help

You can seek out help on our Discord server.

API Documentation

Find API documentation at pkg.go.dev

Contributing

See our Contribution Guide

Getting Started

Install dependencies

• OpenCascade CAD Kernel - Installing a binary package is recommended (compiling takes hours).
• occwrapper OpenCascade C wrapper to help make using OpenCascade with Go easier.

VSCode extension

An extension for VSCode exists to help visualizing what you build:

• MakerCAD-vscode

The extension does require exporting model(s) to stl format (does not preclude exporting to other formats).

Support

If this project is important to you, help:

• Encourage me by sharing what you have made with it (hashtag #makercad)
• Encourage others by sharing MakerCAD with the community
• Help monetarily buy me a coffee

Contributing

• Share MakerCAD with the community
• Show off what you've built tagging #makercad
• Raise an issue for a problem you have encountered
• Submit a pull request for additions / changes / fixes you have worked on

Install MakerCAD

Start a go project

mkdir myproject && go mod init [module-path]

Add makercad dependency

go get github.com/marcuswu/makercad

Start designing!

Using MakerCAD

Start by creating an instance of MakerCad:

cad := makercad.NewMakerCad()

Creating Primitives

Plane

Planes can be used for creating sketches or placing primitives

MyTopPlane := sketcher.NewPlaneParametersFromVectors(
    sketcher.NewVectorFromValues(0, 0, 0),  // Location (origin for the plane)
    sketcher.NewVectorFromValues(0, 0, 1),  // Normal (Z) direction vector
    sketcher.NewVectorFromValues(1, 0, 0),  // X Direction vector
)

A plane can also be created from a face of a model

sketcher.NewPlaneParametersFromCoordinateSystem(aFace.Plane())

There are also some origin planes predefined in MakerCAD:

type MakerCad struct {
	sketches    []*Sketch
	FrontPlane  *sketcher.PlaneParameters
	BackPlane   *sketcher.PlaneParameters
	TopPlane    *sketcher.PlaneParameters
	BottomPlane *sketcher.PlaneParameters
	LeftPlane   *sketcher.PlaneParameters
	RightPlane  *sketcher.PlaneParameters
}

Rectangular Cuboid

Provide a plane to locate and orient the shape, its dimensions, and whether to center it on the location Specific global coordinates can be specified by altering the plane

block := cad.MakeBox(cad.TopPlane, width, depth, height, true | false)

Cylinder

Provide a plane to locate and orient the shape and its radius and height. Cylinders are always centered on the plane origin

cylinder := cad.MakeCylinder(cad.TopPlane, radius, height)

Boolean operations

Boolean operations allow combining shapes to create more complex features on your model. These operations return a CadOperation from which the resulting shape can be retrieved.

Union

op, err = cad.Combine(targetShape, makercad.ListOfShape{tools...})

Difference

op, err = cad.Remove(targetShape, makercad.ListOfShape{tools...})

Sketching

Sketching allows for creation of more complex 3D shapes by drawing a 2D shape, optionally adding constraints and solving them, then extruding or revolving them to 3D shapes

Creating a Sketch

A sketch may be created on a plane or a face of a shape:

sketch := cad.Sketch(plane | face)

Defining Geometry

Lines are defined by start and end points

l1 := sketch.Line(startX, startY, endX, endY)

Arcs are defined clockwise around a center point

arc1 := sketch.Arc(centerX, centerY, startX, startY, endX, endY)

Circles are defined by a center point and a diameter (does not define a constraint)

circ1 := sketch.Circle(centerX, centerY, diameter)

Constraining Geometry

Sometimes it is not easy to determine the exact geometry when defining a sketch. In these cases, let the computer do the work. Define geometry close to what you need and specify constraints to define how the final geometry should relate.

Method	Description
Coincident(Entity, Entity)	Ensure one entity lies on another entity (eg a point on a line)
PointVerticalDistance(*Point, Entity, float64)	Ensures a point is a specific distance along the Y axis from the specified entity
PointHorizontalDistance(*Point, Entity, float64)	Ensures a point is a specific distance along the X axis from the specified entity
PointProjectedDistance(*Point, Entity, float64)	Ensures that a point's projected distance along the normal of Entity is a specific distance
LineMidpoint(*Line, Entity)	Ensures entity is coincident with Line and halfway between its start and end points
LineAngle(*Line, *Line, float64)	Ensures the angle between two lines is the specified angle (in radians)
ArcLineTangent(*Arc, *Line)	Ensures the specified arc and line are tangent to one another
Distance(Entity, Entity, float64)	Ensures the two entities are the specified distance from each other
HorizontalLine(*Line)	Ensures the specified line is parallel with the X axis
HorizontalPoints(*Point, *Point)	Ensures the imaginary line segment between the two points specified is parallel with the X axis
VerticalLine(*Line)	Ensures the specified line is parallel with the X axis
VerticalPoints(*Point, *Point)	Ensures the imaginary line segment between the two points specified is parallel with the X axis
LineLength(*Line, float64)	Ensures the specified line has the indicated length
Equal(Entity, Entity)	Ensures the two entities are equal (lines the same length, circles the same diameter, etc)
CurveDiameter(Entity, float64)	Ensures the arc or circle specified has the indicated diameter

Many of these constraints also have convenience functions on an entity. For instance to set a line's length:

line1.Length(10)

Most of these convenience functions return the entity so they can be chained:

line1.Length(10).Horizontal()

Solving Constraints

Runs the constraint solver algorithm. Returns an error should it be unable to solve.

err = sketch.Solve()

Debugging Sketches

Sketches can be overconstrained or underconstrained. The OverConstrained method returns a list of constraints that overdefine the problem:

fmt.PrintLn("Over constrained constraints: ", sketch.OverConstrained())

An underconstrained sketch will have multiple solutions (often infinite).

A sketch can be converted to an SVG image:

sketch.LogDebug("sketch.svg")

The constraint solver uses a graph based approach to simplifying the system of equations that are necessary to solve a sketch. If there is an issue with a sketch, logging the graph can be helpful in determining why:

sketch.ExportImage("sketch.dot")

These .dot files can be visualized via GraphViz:

dot -Tsvg clustered.dot -o clustered.svg

Extruding or Revolving Sketches

First, convert the sketch into a Face:

face1 := makercad.NewFace(sketch)

Then it can be extruded or revolved

operation, err := face1.Extrude(distance)

operation, err := face1.Revolve(axis, angleInRadians)

With either of these, if combining via a boolean operation with an existing shape, it can be done in one step:

operation1, err := face1.ExtrudeMerging(distance, MergeType, makercad.ListOfShape{someOp.Shape()})
operation2, err := face2.ExtrudeMerging(distance, MergeType, makercad.ListOfShape{someOp.Shape()})

Finding a Face or Edge

A Shape can return its list of Faces:

shape1.Faces()

A Face or list of Faces can return its list of Edges:

face1.Edges()
shape1.Faces().Edges()

A list of Faces or Edges can be filtered and sorted:

someOperation.Shape().Faces().Edges().
  IsCircle().
  Matching(func(e *sketcher.Edge) bool {
    return e.CircleRadius() == 5.8/2.
  })

Connecting the pieces:

  block := cad.MakeBox(cad.TopPlane, blockWidth, blockWidth, blockHeight, true)

  // Find the top face aligned with Z positive
  faces := block.Faces().AlignedWith(cad.TopPlane)
  faces.SortByZ(true)
  topFace := faces[0]

  sketch := cad.Sketch(topFace)
  circle := sketch.Circle(0, 0, 5)
  circle.Diameter(5)
  circle.Center.Coincident(sketch.Origin())
  err := sketch.Solve()
  if err != nil {
    // do something
  }

  face1 := makercad.NewFace(sketch)
  newBlock, err = face1.ExtrudeMerging(-2, makercad.MergeTypeRemove, makercad.ListOfShape{block})

Saving Results

MakerCAD can export to STL or STEP:

exports := makercad.ListOfShape{block}
cad.ExportStl("my-model.stl", exports, makercad.QualityHigh)
cad.ExportStep("my-model.step", exports)