I want to sell the development. How to proceed? Where to go?

Question

Do it yourself

Hello!
I want to sell the development of a 3D printer (some articles can be read on giqtimes)
At the moment, the following has been completed:
1. The idea and its full understanding.
2. Implementation of the idea and testing its performance on the prototype.
3. Production of a pre-production prototype. It was never sold due to the reworking of the design.
4. Production of a serial batch of printers and their implementation.
Developed (all own):
1. Mechanics.
2. Electronics (circuitry, firmware)
3. PC software.
Actually, I would like to sell this development. Where can you apply? And is it realistic to do so? I will be glad to any answers. Thanks