3D printing invention (additive manufacturing) had been around for decades before Dr. Bowyer revolutionized it. All of the 3D printers were huge. Multi-hundred million-dollar machines were used only by a few for very expensive projects. Dr. Bowyer took the basic idea and created a machine, costing a few hundred dollars and can be used for very inexpensive plans.
The RepRap project was what got ALL of the other consumer 3D printers started. Makerbot started as a RepStrap (a printer that can make RepRap parts). Today, and arguably for the future, there are probably at least twice as many RepRap derivatives in use worldwide than all of the commercial models combined.
First Steps (3D Printing Invention)
That’s because RepRaps are largely self-copying. A commercial 3D printer can make a RepRap, but a RepRap can’t make a commercial 3D printer. So the population of RepRaps will increase exponentially. While the population of commercial printers will only boost linearly.
In a few years, when everyone has a 3D printer or has easy access to one, it will be thanks to the RepRap project.
3D printing has allowed for more rapid and cheaper prototyping. It hasn’t fundamentally made anything possible that wasn’t possible to do through other mechanisms.
Nothing was stopping people from casting, severing, cutting, molding or shaping those same parts previously. They were lacking skill and motivation. What 3d printing has allowed is to shift the skills profile required to obtain the same results and accelerated the process.
The essentials include the skills required to turn the ideas into reality. But, even in that case, 3D printing relies on a lot of material science, cheap and accurate motors and microcontrollers, standardized software, PC-based design tools, online community building, and collaboration tools, etc. that all intersected to make 3D-printing viable. So, 3D-printing alone would also have gone nowhere without the entire technology ecosystem to support it.
If that ecosystem existed, 3D-printing was practically unavoidable. Furthermore, we actually did have 3D printing a lot earlier than most people realize, but it wasn’t economically viable as a consumer tool until everything else came together.
Final Organization (3D Printing Invention)
So the question really ends up being, “How would history be different if we had all of the technological advances of the early 2000s sooner?”
Basically, once the product design has been verified and you want to go for mass production, you need to develop ‘production tooling’.
Generally speaking, plastic parts require molds (injection/extrusion/blow molding, depending on what type of part is under consideration).
There are various manufacturing processes for metal parts, depending upon which type of part it is. For example, we can also use Transforming Processes (Forging, Die Pressing, Casting, etc.), Fabrication (Cutting, Bending, Welding, etc.) or Machining which involves removal of material (e.g. Milling, Turning, etc.).
The development of each process requires a certain type of tooling.
You may also consult the OEM manufacturers to develop the necessary tooling for mass production of your product. Moreover, the cost of developing such tooling is very high. It gets amortized over the total production volume.
Therefore, in the case of a high volume of production, cost per piece would also, be pretty low. Consequently, 3D Printing Invention is still a significant thing.