Make a mounting plate that adapts

Understand the change

1. Reuse your first part

   Keep the width, depth and thickness parameters. The new dimensions are an authored example; measure actual mounting points before adapting it to equipment.

2. Locate the holes

   For an 80 mm plate with 50 mm spacing, hole centres are 15 and 65 mm from the left edge. Subtract half the hole diameter to find the remaining material.

3. Change the constraint

   Increase spacing to 70 mm. The end margin becomes 3 mm. Try 74 mm: the assertion rejects the 1 mm margin. Make the plate wider instead of deleting the check.

4. Export and retain the decision

   Render in OpenSCAD, inspect both holes through the full thickness and save the .scad file. Record the measured mounting spacing and the chosen hole allowance in your build notes.

Extend my dimensioned blank into an 80 × 30 × 4 mm plate with two 4 mm holes, 50 mm apart. Centre the holes along Y. Use difference, translate and cylinder. Require 3 mm of material between each hole and the nearest edge. Reject impossible dimensions. Explain what must change if spacing becomes 70 mm. Do not claim a load rating or printed fit.

width = 80;
depth = 30;
thickness = 4;
hole_d = 4;
spacing = 50;
edge = 3;
$fn = 64;
assert(width > 0 && depth > 0 && thickness > 0);
assert(hole_d > 0 && spacing > hole_d);
assert((width-spacing-hole_d)/2 >= edge, "Increase width or reduce spacing");
assert((depth-hole_d)/2 >= edge, "Increase depth or reduce hole diameter");
difference() {
  cube([width, depth, thickness]);
  for (x = [(width-spacing)/2, (width+spacing)/2])
    translate([x, depth/2, -1])
      cylinder(h=thickness+2, d=hole_d);
}