New Dimensions

3D printing provides a new source for rare metallic and composite…

Story and photos by Dan Burrill

Finding obsolete parts to keep an old car running or to restore a classic car has become a real challenge over the years. Now with 3D printing becoming more popular and widely available, this process has become a real boon to restorers and builders of classic replicas. 3D printing has been expensive in the past, but now more companies are offering the service, so it’s becoming more affordable.

The process starts with the original part being photographed from all sides. In this case, three cameras are being used.

The images are then transferred to a CAD program.

The CAD images are then transferred to a 3D printer.

The actual item is printed using powder and an adhesive that is sprayed out as the powder is released.

The printed part is then used to make a mold of wax or a similar material. The outside of the mold is a ceramic material that encases the wax.

The basic process consists of material such as liquid molecules or powder grains being fused or solidified under computer control to create a 3D object. Objects can be of almost any shape or geometry and typically are produced using digital model data from a CAD file. Material is added up, layer by layer, until the part is complete.

A mold is made for producing three pulleys at a time, which is then fired in a kiln.

The metal ingots that will be used to make the actual pulleys are melted down.

For illustration purposes, the part being produced here is a pulley from the air conditioning pump on an older Ford Thunderbird. Since this particular pulley is no longer available, we’d normally resort to scrounging the salvage yards or swap meets. Sometimes these parts can be found on sites like eBay, but that can be a hit-or-miss scenario. And even if you find one, you’d end up with an overpriced, old pulley that might crack and break as the metal fatigued.

The molten steel is poured into the ceramic molds.

Once the steel has cooled and is solid, the ceramic material is chipped off, leaving the steel exposed.

At this point, the raw pulleys are cut off from the supports, and the finishing work starts.

The raw pulleys are deburred, sanded and smoothed.

Now the center hole can be drilled and the keyway can be cut as well.

So, we’ve decided to take an original part that we have in hand and create new ones using 3D printing. This approach can be used with just about any part that needs to be freshly fabricated. The process is digital magic. Simply photograph the old part in hand or, if it’s not readily available, draw a new one on the screen. Then follow the steps outlined below, and in the end, you’ll be holding the item in your hand.