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Custom Jewelry Ring
Custom Jewelry Ring
For my spring 2025 manufacturing project, I selected to machine and engrave a custom jewelry ring using a Tormach 3-axis mill. The completion of the ring required me to learn 3D machining skills on the Tormach 1100M as well as unique workholding techniques.
Before I was even able to begin modeling the ring, I first had to acquire and machine a custom ID (inner diameter) clamp which would hold the ring in the later stages of the machining process. Creating this clamp required learning additional skills such as steel machining, manual tapping, and drill tapping. The clamp setup consisted of a 0.53-0.79" Mild Steel ID Expansion Clamp (purchased from shars.com) and a custom machined fixture to secure the clamp to the machine bed.
The basic fixture was machined on the 1100M using tool 1 with a 2D pocket operation. After machining the custom fixture, I tapped the three holes using a hand drill tap.
Machining speeds and feeds were calculated using the free online tool from littlemachineshop.com
The ring was designed with my personal measurements in mind, basing the diameter off of a US size 10 ring with an inner diameter of ⌀0.781in (based off of a carreracasting.com chart). I wanted to prioritize comfort and fluid curves into the design, leading to the initial draft of the ring and round inner profile.
Learning a new type of 3D CAM operation associated with the torus shape was necessary in the completion of the manufacturing process. The 3D Contour operation (see above) used with a ⌀0.25in ball-nose end mill (T24) allowed me to create the curved shell shape both outside and inside the ring on a 3-axis machine. Important settings I included were model, order bottom-up, and a cusp height of 0.0001in (thousandth). The model toggle under the geometry tab allowed me to avoid machining the inside of the ring with the same operation after selecting a cylinder to "avoid" (see above). This was done in order to avoid collision with the inner diameter clamp in my particular setup. Ordering the passes from bottom-up allowed me to remove all the excess stock in the initial pass, and then ascend while completing the finishing pass. Finally, the tiny cusp height I selected gave me the smoothest possible finish (within reason) on the outside of the ring.
3D Contour operation
Model "to avoid"
During the machining process, I encountered minimal CAM errors allowing me to spend the majority of my time experimenting with various workholds. The only significant issue was a discrepancy between the diameter of T24 listed in the tool library (⌀0.2311in) versus the physical tool diameter (⌀0.25in). Aside from this, I encountered most of my difficulties in grappling with the ID clamp, a workholding method unknown to me at the start of the project. My initial attempt at fixing the half-ring to the ID clamp resulted in a fit that was not tight enough, allowing the stock to move with a human amount of force. I overcompensated on the following workhold, which resulted in too much force being applied to the inner diameter of the ring thus deforming it (see image).
Upper "bite" marks from clamp
Final Product
Final Product
My final attempt found the right balance of force required to effectively workhold the stock without bending it. The resulting piece was a success; the ring fit my finger well, and the program was executed correctly with the final product closely resembling the model.
Bonus
Bonus
After creating several rings, I decided to try an additional engraving to the outside of a ring. I attempted this with the project operation, which allowed me to engrave on the curved 3D surface. I opted to engrave a simple wave shape that represents our school's vicinity with the ocean. The effect worked relatively well, but a more geometrically perfect ring would result in a better engraving.
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