Mounting Plate

A mounting plate with a regular hole pattern is one of the most common CAD tasks. This recipe shows the idiomatic vcad approach.

The Pattern

The key insight is using linear_pattern to create a grid of holes efficiently:

use vcad::{centered_cube, centered_cylinder};

let plate = centered_cube("plate", 100.0, 60.0, 5.0);

let hole = centered_cylinder("hole", 3.0, 10.0, 32);
let holes = hole
    .linear_pattern(80.0, 0.0, 0.0, 2)   // 2 copies, 80mm apart in X
    .linear_pattern(0.0, 40.0, 0.0, 2)   // then 2 copies, 40mm apart in Y
    .translate(-40.0, -20.0, 0.0);       // center the pattern

let part = plate - holes;

Step by Step

1. Create the base plate

let plate = centered_cube("plate", 100.0, 60.0, 5.0);

Using centered_cube makes positioning easier—the plate is centered at the origin.

2. Create one hole

let hole = centered_cylinder("hole", 3.0, 10.0, 32);

Make the hole taller than the plate (10mm vs 5mm) to ensure it cuts through completely.

3. Pattern the hole

let holes = hole
    .linear_pattern(80.0, 0.0, 0.0, 2)   // 2 in X direction
    .linear_pattern(0.0, 40.0, 0.0, 2);  // then 2 in Y direction

This creates 4 holes in a 80mm × 40mm grid.

4. Center the pattern

let holes = holes.translate(-40.0, -20.0, 0.0);

The pattern starts at origin, so we shift it by half the spacing to center it on the plate.

5. Subtract the holes

let part = plate - holes;

Variations

Different hole counts

For a 3×2 pattern (6 holes):

let holes = hole
    .linear_pattern(40.0, 0.0, 0.0, 3)   // 3 in X, 40mm apart
    .linear_pattern(0.0, 40.0, 0.0, 2)   // 2 in Y, 40mm apart
    .translate(-40.0, -20.0, 0.0);

Edge-based positioning

If you want holes inset from the edges:

let inset = 10.0;  // mm from edge
let plate_w = 100.0;
let plate_h = 60.0;

let spacing_x = plate_w - 2.0 * inset;  // 80mm
let spacing_y = plate_h - 2.0 * inset;  // 40mm

let holes = hole
    .linear_pattern(spacing_x, 0.0, 0.0, 2)
    .linear_pattern(0.0, spacing_y, 0.0, 2)
    .translate(-spacing_x / 2.0, -spacing_y / 2.0, 0.0);

Countersunk holes

For flat-head screws:

use vcad::counterbore_hole;

let hole = counterbore_hole(
    5.5,   // through hole dia
    10.0,  // counterbore dia
    5.0,   // counterbore depth
    10.0,  // total depth
    32     // segments
);

Complete Code

use vcad::{centered_cube, centered_cylinder, Part};

fn mounting_plate(
    width: f64,
    height: f64,
    thickness: f64,
    hole_dia: f64,
    hole_inset: f64,
) -> Part {
    let plate = centered_cube("plate", width, height, thickness);

    let spacing_x = width - 2.0 * hole_inset;
    let spacing_y = height - 2.0 * hole_inset;

    let hole = centered_cylinder("hole", hole_dia / 2.0, thickness + 5.0, 32);
    let holes = hole
        .linear_pattern(spacing_x, 0.0, 0.0, 2)
        .linear_pattern(0.0, spacing_y, 0.0, 2)
        .translate(-spacing_x / 2.0, -spacing_y / 2.0, 0.0);

    plate - holes
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let part = mounting_plate(100.0, 60.0, 5.0, 6.0, 10.0);
    part.write_stl("plate.stl")?;
    Ok(())
}