Cutting Jig for Grid Beam (for use with openjscad.xyz)

cutting-jig.js

/**
 * Cutting Jig for Grid Beam
 * @category Grid Beam
 * @skillLevel 1
 * @description A jig to help accurately cut to the grid
 * @tags grid beam, cutting, jig
 * @authors Michael Williams
 * @licence LGPL-3.0 License
 */

module.exports = { main }

const { subtract } = require('@jscad/modeling').booleans
const { translate } = require('@jscad/modeling').transforms
const { cuboid, cylinder } = require('@jscad/modeling').primitives

const GRID_SPACING = 40
const CUTTER_KERF = 0.635
const HOLE_DIAMETER = 7.5 // drill tap size
const JIG_BASE_GRIDS = 2
const JIG_BASE_HEIGHT = 10
const CYLINDER_RESOLUTION = 32

function main() {
  return subtract(jigBase(), jigHoles())
}

function jigBase() {
  const jigLength = GRID_SPACING * JIG_BASE_GRIDS
  const jigWidth = GRID_SPACING
  const jigHeight = JIG_BASE_HEIGHT

  return cuboid({
    center: [(1 / 2) * jigLength, (1 / 2) * jigWidth, (1 / 2) * jigHeight],
    size: [jigLength - 2 * CUTTER_KERF, jigWidth, jigHeight],
  })
}

function jigHoles() {
  const holes = []
  for (let holeIndex = 0; holeIndex < JIG_BASE_GRIDS; holeIndex++) {
    const hole = translate(
      [(1 / 2 + holeIndex) * GRID_SPACING, (1 / 2) * GRID_SPACING, 0],
      jigHole(),
    )
    holes.push(hole)
  }
  return holes
}

function jigHole() {
  return cylinder({
    center: [0, 0, JIG_BASE_HEIGHT / 2],
    height: JIG_BASE_HEIGHT,
    radius: HOLE_DIAMETER / 2,
    segments: CYLINDER_RESOLUTION,
  })
}