What's Your Angle?

In another article on fabrication, we studied the benefits of manufacturing parts for vehicles that could not be obtained, did not fit our purpose or were easier to make than to track down and buy. Next we will go into some of the finer details of manufacturing these parts.


Even if you have decided to produce the part yourself, it is unlikely you have the luxury of access to a full array of computer-controlled machines and computer-aided design software. Here is some of the machinery more common to a home machine shop.

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The main piece of equipment is a vertical milling machine, and the accessories often found with it. This machine looks like a really stout drill press with a table that can be moved very accurately with hand cranks. It allows you to drill and cut and shape a variety of metal components (including those rare car parts mentioned at the outset). Angles and radii present their own special problems in manufacturing, and yes, even their own special math; therefore, there are several special tools to assist you in creating certain shapes.


Chances are that if you are making a custom part for your vehicle, it will not be shaped like a simple rectangle. A quick look at just about any car part will tell you that they have complex angles and curves due to the complicated jobs that the parts accomplish. When one of these components must be made, however, they will often start out as square or rectangular stock. And the more accurately you can make the square, the easier it is to maintain the accuracy of the part throughout the manufacturing process.


First of all, let's begin by saying that no piece of machine equipment comes perfectly aligned and square from the factory. Before any machine work is attempted, it is important to make sure that your milling machine head is perfectly square to the table by taking a variety of measurements (.005 of an inch in tolerance is typical).