3D printing services look set to save lives with use in hospitals and medical research including to make spare parts for people but they also look set to save cars by being used to fabricate parts that simply don’t exist any more for old cars or where the parts are so rare it is cheaper to make them from scratch.
The process of making spare car parts often starts with the old part, if it exists, it could be in bad shape of course for example cracked or rusted through in places but if it can be 3D scanned then repairs can be done in a CAD program to create a 3D model of the piece how it should be.
If you don’t have the part, often the case where you have bought a shell of a car that could have been stripped for parts already, then you have a couple of choices you could borrow a part from a fellow enthusiast or get hold of the original plans, likely to be possible if the car has been mass produced and the manufacturer still exists. From these 2D plans you can then build up a 3D CAD model or pay someone else to do it, some companies are starting to setup selling 3D CAD designs of hard to get parts for in demand vintage cars such as Jaguar E types and DeLoreans.
With many pre war vehicles though there are simply no plans to copy or parts to scan, many unique one of a kind vehicle sit unused for lack of parts but using CAD you can now build up a part. Of course if you were going to have the part made at massive expense using traditional production techniques you would have to get the CAD model just right, which can be almost impossible especially with metal pipes that have to bend in just the right places.
With a 3D printing service though you can use it for rapid prototyping parts in plastic to make sure they fit, the eventual material isn’t important for now, you are checking that your part will be the right size and shape and due to the low cost and quick speed of a print you can use trial and error to get the perfect design.
Now with some car parts, fasteners, brackets and so on the material may not be too important and a heat resistant tough resin based plastic may be fine for your purposes, if so simply use a 3D printing service to print the part. There are now a few companies setup to receive your CAD files who will then print parts for you and send them to you by post.
If you are a professional car restorer though or like Jay Leno a rich hobbyist, then you may want your own 3D printer; Jay Leno has a fantastic collection of cars, many unique and many over a hundred years old for which the parts don’t exist so he has a setup including his own 3D printing service.
As for parts that need to be made in metal, which is often the case as metal parts do tend to rust eventually, with traditional techniques it would be very expensive to hand make molds for one off parts and would take weeks. Now though by printing parts in plastic using a 3D printing service you can then make a mould around them in next to no time: the mold is then used to cast a new part in aluminum or steel.