What’s hold in this repository?
In the present repository you will find all the documentation needed to assemble a BCN3D Sigma, from the warehouse to the box. In our commitment to Open Source, we want to be transparent, not only in the design, but also in the processes involved in the BCN3D Sigma manufacture.
Since it’s our first experience producing in an assembly line, we’ve built the structure from the ground up. In the process we have made some mistakes and faced many challenges. But day after day, we improved and deployed a solid system that is allowing us to increase month after month our production capacity in order to satisfy the growing demand.
The process starts when we receive the components from our Suppliers. We check all of them in a variable proportion depending on nature of the element. Some of them, like standard mechanical or electronic components are just visually checked, while others, like custom metal sheets or electronics boards are thoroughly checked.
Since the very first day we adopted Lean Manufacturing in the Sigma assembly line. Instead of implementing a Push System, producing lots of a certain number of printers, independently of the demand, we established a Pull System, based on Kanban scheduling system, where we produce depending on the number of printers sold. In other words, the sells are “pulling” the production efforts.
This philosophy makes us more flexible and able to react to fluctuations in the demand, as well as allows us to reduce all the stocks in the production process, both the components, the semi-elaborated product and the final product.
We broke this concept apart so we planned to assemble the BCN3D Sigma in several blocks, which could be redistributed in different workstations as the production grows. The first step, though, is supplying all the material needed to each workstation and make sure it never lacks.
Therefore, we produced the “Kit Sheets”, where the components needed in every step of the assembling process are listed. Moreover, these sheets specify the quantity of kits each workstation should have to never run out of material. Finally, this document allows us to trace the key components so, at the end of the day, we know exactly the composition of a Sigma. This can help us in case we detect a generalized problem with some of the traceable components, so we can find all the printers potentially affected.
Probably the most important document in the whole process, the Assembly Guide provides step by step guide for the worker. This grants all the Sigmas are assembled equally, no matter if the worker is new or it’s been working with us since the very first day. In addition, it points not only the jigs or tools needed, but also the verifications to do during the assembly and some warnings.
As explained before, the Sigma is built in different stages, so the Assembly Guide is divided in several chapters that can be redistributed if needed, increasing the efficiency and flexibility of the assembly line.
Jigs and Fixtures
The BCN3D Sigma is a high-precision equipment, so it is mandatory to assemble it meticulously. On the other hand, assembly time is a key factor we intend to reduce steadily. Both factors force us to design several jigs and fixtures to make sure the axes are properly aligned and the time needed to built a Sigma can be reduced day after day.
Once the Sigma is assembled, it’s time to verify it works perfectly. Every single printer undergoes a thorough Quality Protocol that checks its finish as well as its mechanical and electronic systems. Finally, the Sigma prints some test parts during approximately 25h.