Helical

Helical is a library for Cadova that simplifies the creation of threaded components and related parts. It supports widely-used metric threads, bolts, and nuts, as well as the ability to customize these components to fit specific requirements.

Bolts demo · Nuts and washers demo

Installation

Integrate Helical into your project with the Swift Package Manager by adding it as a dependency in your Package.swift file:

.package(url: "https://github.com/tomasf/Helical.git", from: "1.0.0")

Then, import Helical where it's needed:

import Helical

Usage

Standard Components

Helical simplifies the process of creating threaded shapes, making it easier to incorporate threaded holes into your models. It also provides a selection of standard bolts, nuts, and corresponding holes. Creating a typical M8x20 hex head bolt is simple:

Bolt.hexHead(.m8, length: 20, unthreadedLength: 5)

This generates a standard DIN 931 bolt, as expected.

Customizing Components

Beyond the standard offerings, Helical allows for modifications to fit unique requirements:

Bolt.hexHead(
    .isoMetric(.m8, pitch: 0.75),
    headWidth: 15,
    headHeight: 6.5,
    length: 20
)

Or fully customize parts to your specific needs:

let thread = ScrewThread(
    handedness: .left,
    starts: 2,
    pitch: 1.5,
    majorDiameter: 6.2,
    minorDiameter: 5.3,
    form: .trapezoidal(angle: 90°, crestWidth: 0.25)
)
let customBolt = Bolt(
    thread: thread,
    length: 15,
    unthreadedLength: 3,
    unthreadedDiameter: 5,
    headShape: .countersunk(angle: 80°, topDiameter: 10, boltDiameter: 5),
    socket: .slot(length: 10, width: 1, depth: 1.4)
)

Holes

Creating a matching countersunk clearance hole for a bolt is straightforward:

Box(13)
    .aligned(at: .centerXY)
    .subtracting {
        customBolt.clearanceHole(entry: .recessedHead)
    }

As is making a threaded hole for a particular thread:

Box(13)
    .aligned(at: .centerXY)
    .subtracting {
        ThreadedHole(thread: thread, depth: 13, leadIns: .both)
    }

Lead-In Chamfers

LeadIn and LeadInEnds provide a unified way to add thread-entry chamfers to screws, threaded holes, and nuts. Size can be specified relative to thread depth, pitch, or cone angle, or as explicit dimensions:

Screw(thread: .isoMetric(.m6), length: 20, leadIns: .both(.standard))

Nut(thread: .isoMetric(.m6), shape: body, leadIns: .both(.angle(120°)))

Behavior

Helical uses Cadova's tolerance environment setting to increase the diameter of holes and decrease the diameter of bolts. Clearance holes can create overhang-safe shapes. Specify a circular overhang method (circularOverhangMethod) to enable this.

.withCircularOverhangMethod(.bridge)
.withTolerance(0.5)

Contributing

We welcome contributions. Feel free to open issues for feedback or suggestions and submit pull requests for improvements to the codebase.