It took me two years, from idea to design. Now, I am one year into adjusting and perfecting the manufacturing processes needed to materialize it.
I started with the bracelet. Seemingly simple, it proved harder to make than expected. My first iteration showed two major problems: drilling the hole that connects the links and the stiffness of the assembly after heat treatment.
The last one occurred because of the deformation caused by the treatment. Luckily, this had a straightforward solution: heat-treating it in a vacuum-controlled environment and quenching with nitrogen. This prevents oxidation, ensures uniform cooling, and reduces deformation from 0.14mm to 0.02mm—sufficient to comply with design tolerances.
On the other hand, the drilling problem needed further analysis. To drill the hole all the way through the part, I needed to use a Ø1.2×30mm drill. These dimensions are far from the ideal ratio (length = 3*Ø) and allow the tool to flex during the operation.
Rethinking the connection method—from a single hole to two aligned holes (one per side)—enabled me to reduce the tool’s overall length to 9mm—closer to ideal.
To achieve the needed rigidity, a custom tool was made, reducing the cutting zone length and thickening the body, enabling the tool to drill perfectly straight holes.
These changes made all the difference—resulting in a dimensionally rigid bracelet that conforms effortlessly to the wrist.
RA.Gracioli