I. Project Background
A jewelry design studio, aiming to explore novel design concepts, planned to produce a batch of creative ring models for display at a new product launch and verification of design concepts. Due to the complex design, including hollow structures and unique patterns, traditional processing methods were difficult to implement efficiently. Therefore, a process scheme combining 3D printing, CNC post – processing, and vacuum casting was chosen.
II. Requirement Analysis
- Accuracy Requirement: The dimensions of the ring models need to be precise to ensure that design details (such as the diameter of hollow holes and the contours of patterns) are clearly presented, with an error controlled within ±0.1mm, so as to match the subsequent jewelry production standards.
- Material Requirement: Yellow photosensitive resin is selected. It should have good formability and toughness, uniform color, and a smooth surface after printing, which is convenient for subsequent processes such as polishing and coloring, meeting the aesthetic requirements for jewelry display.
- Process Requirement: First, 3D printing is used for rapid prototyping. Then, CNC machining is employed to finely correct key dimensions (such as the inner diameter of the ring). Some models are replicated in small batches using the vacuum casting process to ensure the consistency of multiple models.
III. Production Process
(I) 3D Printing Stage
- Model Slicing: Import the 3D design file of the ring (in STL format). Use professional slicing software, set the layer thickness to 0.05mm, and reasonably plan the support structures. Add easy – to – remove supports for hollow and overhanging parts (such as the patterns on the top of the ring) to ensure the stability of the printing process.
- Printing Parameters: Use a photosensitive resin 3D printer. Set the printing speed to 50mm/s, the light power to 80mW, and print in a constant temperature environment of 25°C to ensure uniform curing of the resin and high forming accuracy. It takes 4 hours to complete the printing of the first batch of 5 ring models. The appearance after forming is highly consistent with the design, and the color of the yellow resin is bright.
(II) CNC Post – processing Stage
- Clamping and Positioning: Fix the 3D – printed ring model on the CNC machining table. Use high – precision fixtures and position with the outer ring of the ring as the reference to ensure no deviation during the machining process.
- Machining and Correction: Compile the CNC machining path. Select a micro – milling cutter to finely mill the inner diameter of the ring to correct the minor dimensional deviations that may occur in 3D printing. At the same time, perform light milling and polishing on the surface of the model to remove the printing layer lines and improve the surface finish. The CNC processing of a single ring takes about 30 minutes. After processing, the dimensional accuracy of the inner ring reaches ±0.05mm, and the surface roughness is Ra0.8μm.
(III) Application of Vacuum Casting Process (Optional for Small – batch Replication)
- Mold Making: Select 1 high – quality ring model after CNC processing to make a silicone mold. Use the vacuum casting process to ensure that the mold cavity accurately replicates the details of the model. The hardness of the silicone mold is moderate, which is convenient for demolding.
- Small – batch Vacuum Casting: Inject the same – color photosensitive resin material (or suitable vacuum casting material) into the mold cavity. After curing and demolding, produce ring models in small batches. The dimensional accuracy of the vacuum – cast parts is consistent with the original model, and the surface quality is good, meeting the needs of small – batch display.
IV. Project Achievements
Through the combined process of 3D printing + CNC machining + vacuum casting, the production of creative ring models is efficiently completed:
- Accuracy Meets the Standard: The dimensional errors of key parts of the model are all controlled within the design requirements. The details such as hollows and patterns are clear, perfectly presenting the design concepts.
- High – quality Appearance: The color of the yellow resin is uniform. After CNC processing and polishing, the surface is smooth and bright, meeting the high – quality requirements for jewelry display.
- Efficiency Improved: Compared with pure manual or traditional processing, the process cycle is shortened by 60%. Moreover, small – batch rapid replication can be realized through vacuum casting, helping the design studio to efficiently promote the preparation work for the new product launch and providing accurate design verification models for subsequent jewelry mass production.
