Currently, producing a new car from a new design represents either a significant investment in tooling, or a large commitment in time for someone to produce a design free form if the tooling does not exist. In addition the need for all that production tooling is the result of just how many parts are required to produce the structure of a car. Just to create the cabin of a car, there are exterior body panels, trim, internal structure for rigidity, interior panels, dash covers... even the seats themselves contribute to a seriously overblown Bill of Materials. So the fundamental issue is, what can be done to reduce the initial investment in producing a design, reduce the part count, and reduce the follow-up investment that will be required if the design changes? Imagine if you could create the major elements of the exterior, the structure, and the Interior associated with a vehicle in one part. Then think if changing the design, or even taking on an entirely new one represented no additional cost in tooling. This is what we want investigated in the Direct Digital Manufacturing Project!
While "Direct Digital Manufacturing" (DDM) is a term that can refer to many processes, for this portion of it we are focused on investigating the proper use of a hybrid additive/subtractive machine the is being developed at Oak Ridge National Labs. This machine uses a large diameter extrusion head to 3D print objects at high speed, then on the same head it also uses a router to come back and machine surfaces to a more precise specification where required. This means that we can create car-scale forms very quickly and freely to machined precision, but without the necessity of forming tools, etc. The challenges are to figure out what the best structure looks like? What materials should be used and when? What is the best way to fasten to that structure, and so on.
Once we have answered the above questions, we have certain objectives that we will use that knowledge to complete:
- To create the majority structure of a new vehicle using an additive/subtractive hybrid methodology.
- To define this methodology enough to do an aesthetic study in how this vehicle could be styled.
- To apply an electric powertrain to this vehicle and have the structure support it.
- To DEMONSTRATE that this methodology could be more economical compared to other existing methods, with a early build happening at the IMTS show in 2014, and following up with creating a production level design in the months following the show.