Creating a Drilled Break Rotor
by Daniel Buck
www.danielbuck.net

The most obvious way to "drill" the holes/slots into break rotors is to use booleans. I personally don't like Booleans much at all. This tutorial will outline the method I use for modeling break rotors.

In the Left viewport at coordinates 0,0,0 create a donut spline (shapes/splines/donut) You may want to increase the interpolation steps for a smoother curve. (I used 30 steps)

I put Radius 1 at 85 and Radius 2 at 50. use whatever suits you.

Now create 4 circle splines as shown in this picture. I used a radius of 2.5. You don't have to use circles, you can use any shape you want, circles are the most common.

Select the 4 circle splines and set their center point to coordinates 0,0,0. (specifically, the Z axis) Do this by going into the hierarchy tab, clicking on "affect pivot only", then open up the "Move Transform Type-In" dialog, (right click on the "select and move tool") and type 0 for the Absolute:World Z axis.

This will let all the circles rotate around the same point. very handy for the next few steps.

Rotate the circles (I used 5 degree increments) to something like this:

With all 4 circles selected, use the Array Tool (Tools/Array). and rotate them on the Z axis by 360 degrees, and a 1D count of 12 (or whatever you prefer).

You will end up with something like this:

Convert the donut to an editable spline and attach all the circle splines together into 1 spline. This makes them all one object.

Now just use the extrude or shell modifier, and you have a break rotor! I extruded with an amount of 2.5

The possibilities for circle patterns (or other shapes) drilled into the rotors is quite vast, try different patterns to give each one of your vehicles a different look. :-)

© Daniel Buck