Custom Car Part Fabrication Tools - Part 2

Typical tools for making custom parts

Matt Carlson / autoMedia.com

In our first installment on fabrication we discussed some of the reasons that a part might be fabricated. Some parts may no longer exist due to the rarity of the vehicle. In this instance a new part would need to be built or a similar part would have to be modified to work. In some circumstances, such as in the case of racing classic cars, the original parts might not bear up under the stresses that occur within the vehicle. The solution for this is to build a new part that is designed to be strong enough to survive when the going gets rough.

Time Vs. Money

While it may seem like a great difficulty to produce one-off parts for old and rare vehicles, it is possible for some parts to be constructed in a relatively short period of time. Rapid fabrication is due in part to advances in technology. However, a complicated item such as a brake or engine part will require time and expensive machinery to produce.

One of the first things that anyone might want to know about a custom-fabricated part is how much it is going to cost. The expense is directly proportional to the amount of time and machinery that is required to make the part.

Obviously the Porsche 914 door panels mentioned in the first article would be fairly inexpensive. In contrast, an engine part will require more time and machinery.

Types of Machines

What kinds of machines and equipment are we talking about? Most of this equipment is found in, oddly enough, a machine shop. This is a generic term for a shop that specializes in the cutting of raw metals and plastics into completed parts. Most successful custom automotive and restoration shops will have a machine shop, or are closely affiliated with one.

The main machines that are used in a machine shop are called milling machines and lathes, though many other machines support the operations of a shop. In the olden days a person manually operated these machines via hand cranks and levers.

If you have an old or rare car, many of the parts were probably manufactured on machines much like these, but set up for high production rates. Almost all machine shops have a few manual machines to perform small or simple operations. Difficult-to-manufacture parts can be produced with a manual machine, but it can become extremely complicated and time consuming.

Computer Age

Thus enters new technology in the form of automatic computer controlled milling machines and lathes. Interestingly, these machines came into use in the early 1950s. Most large automotive manufacturers began using them as soon as possible, because the high production rates that these machines could achieve were obvious. However, only the past couple of decades have seen a wide use in smaller machine shops.

Imagine that you have a rare car with an engine part that you just can't buy anywhere. This old part can be measured with a coordinate measuring machine, or even a machine that scans a digital image and records the dimensions. These dimensions can be loaded into a computer aided manufacturing program, which will produce the code that the actual automatic milling machine or lathe will use to cut the part.

Often the person manufacturing the part will watch a computer image of the part being machined before any metal is ever cut. Surprisingly, this whole process is often faster than making a single part on a manual machine.

High-Tech Costs

So why aren't the parts dirt cheap? Well, the expense of these automatic machines is still very high. A small and simple automatic machine can still start at $40,000. If it is to be used on a regular six- to eight-hour daily schedule, the maintenance costs are higher than they are for your car.

The coordinate measuring machine can cost upwards of $25,000. And some computer aided machining software packages cost in the range of $20,000 for a good version, but not for the best version. Obviously the machine shop has to recoup all of this money to stay in business for very long.

In addition to the expense of the equipment and the material, there can be additional costs for the parts needed to hold the part in place while it's being machined. Many times, due to the shape of the part, it simply cannot be held in a vice or some sort of clamp while it is in the machine. In these situations, special tools need to be manufactured so that the part can be safely secured. Obviously the machinist building these parts has to plan far in advance to decide what is needed to make the parts, and try to keep the price as affordable as possible.

Still want to have some custom parts built for your vehicle? No need to be nervous about the complications that seem to be involved in the manufacturing process. Parts like this have been manufactured for as long as cars have been produced. Chances are that it has become easier and less expensive to make the part now than when the car was new.

So, if you can't buy it, then build it yourself—or have someone else build it for you.