OpenSCAD – Basic Bearing

Not the standard approach to a Bearing this model begins with 2D Representations of each race component and uses rotate_extrude to build up the 3D Body.

Sometimes, if we know the shape is going to be uniform around an axis, it may be easier to create the shape in 2 dimensions. When the shape is complete we can use rotate_extrude to build up the 3d model. This is the approach used in many full feature CAD system. This sample is made as an example of the approach.

Race Profiles in 2D Render ( F6 )

We can use the 2d system where it seems appropriate and, after they are extruded into 3d, add the 3d components.

Here is all the code to create this model, you can copy and paste this code directly into you OpenSCAD editor.

rotate_extrude($fn=50){
  difference() {
    translate([10, 0, 0]){
      square([10, 9], center=true);
    }

    translate([15, 0, 0]){
      circle(r=5);
    }
  }
  difference() {
    translate([20, 0, 0]){
      square([10, 9], center=true);
    }

    translate([15, 0, 0]){
      circle(r=5);
    }
  }
}
for (i = [1 : abs(1) : 10]) {
  rotate([0, 0, (i * 36)]){
    translate([15, 0, 0]){
      {
        $fn=50;    //set sides to 50
        sphere(r=4.5);
      }
    }
 

2 Replies to “OpenSCAD – Basic Bearing”

  1. Steve

    I went to parametrize and simplify this, here’s what I got (also after fixing a few typos in the original recipe):
    “`
    pi = 3.141592653;
    $fn = 60;

    rball = 4.5; // ball radius
    sball = 0.5; // ball spacing
    height = 2*rball; // full height
    rinner = 15; // inner (axle) radius
    router = 30; // outer radius
    rdiff = router-rinner;
    rcentr = (router+rinner)/2;

    rotate_extrude(){
    difference() {
    translate([rcentr, 0, 0])
    square([rdiff, height], center=true);
    translate([rcentr, 0, 0]){
    circle(r = rball+sball);
    }
    }
    }

    nballs = floor(pi * rcentr/(rball+sball));
    echo(rcentr, rball, nballs);
    for (i = [1 : nballs]) {
    rotate([0, 0, (i * 360/nballs)])
    translate([rcentr, 0, 0])
    sphere(r = rball);
    }
    “`
    Thanks for the initial code 😉

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