Report: Design and Fabrication a Business Card Holder
In the current semester, all students have been assigned the task of designing and fabricating a business cardholder. Through the course of the semester, we have learned many techniques and acquired skills in the design and manufacture of 6061-T6 aluminum stock parts. Working hands-on in the cardholder business improved our understanding of the manufacturing techniques and other skills taught in class. The experience has prepared students for entry into the engineering industry.
The assignment involved cutting and machining a 6061-T6 aluminum bar to create a business cardholder while documenting each step of the process in order to make repetition of the procedure possible in future. The first step in the design and fabrication of the card holder was the generation of the engineering drawings. For this task, Solidworks and HSMworks software were used to design and apply tolerances control to the design. The second task was the actual fabrication, in which several machines such as the horizontal bandsaw, Haas VF-2 CNC mill, and Haas VF-3 CNC mill were used. Also, a lot of manual operations were done to ensure a nicely finished product that was aesthetically appealing. These included the use of hand-held files to smoothen the product and inspection of the dimensions.
In the design and fabrication of the business card holder, the major constraint encountered was the lack of access to the required machines. For example, in the CNC machine operations, the students were only allowed to only use the Haas VF-2 machine for the first operation and the Haas VF-3 CNC milling machine for the second operation. Also, the operations were limited to specific flutes such as 3.0” 6-Flute Carbide Insert Face Mill, 0.75” 4-Flute Carbide End Mill, 0.5” 24-Flute HSS 45 degree Chamfer Tool, Edge Finder, and the 6” Kurt machine vise. Secondly, there was no budget allocation for this project but instead all the materials were provided.
After generating the engineering drawings using Solidworks, we started working on the business cardholder. First, we obtained a 0.75” x 2.50” 6061-T6 aluminum bar stock from the store and proceeded to measured 5.70” along its length. The measured section was then cut out using a horizontal band saw. A file was then used to deburr the edges in order to prepare the stock part for the first CNC operation. Also, the saw’s blade setting were double checked to ensure that the blade speed was configured to the required surface speed, and that the feed rate was set to a slow and safe figure.
HSMworks was the used to create a tool path for the machining operations, and the resulting drawing was uploaded to the Haas VF-2 CNC mill. Then the part was inserted into Haas VF-2 CNC mill for the start of the first operation of machining the business cardholder. A 3.0” 6 flute carbide insert face mill was used to machine the top surface of the stock, and a 0.75” 4 flute carbide end mill was used to machine the sides of the stock part. A 0.5” 45° 4 flute chamfer tool was then used to machine all the outside edges. After this first operation was complete, the part was then taken to the metrology lab for inspection to ensure that it met all the tolerance requirements. In this stage, a digital caliper was used to measure the machined length, width, and height of the stock part. Surtronic 3+ tool was used to inspect the flatness of the machined part while an optical comparator was used to measure its roughness. The fillets and chamfer were inspected manually through observation.
In the second operation, a 3.0” 6 flute carbide insert face mill was used to finish the top surface of the machined part. A 0.5” 4 flute carbide center cutting end mill was used to machine the pocket of the part and a 0.75” 4 flute carbide center cutting end mill was used to machine the ramp while a 0.5” 2 flute HSS 45° chamfer tool was used to finish the inside and outside edges of the part. The part was then taken back to the metrology lab for re-inspection and the same tools as before were used. The second inspection focused on dimensions and tolerances accuracy.
Finally, the fully machined part was sent to another company for anodizing. Anodizing was done to give color and improve durability and corrosion resistance. Afterwards, the part was taken to the Startup Lab for personalization through engraving of personal details. The Epilog Laser Mini machine was used to engrave logos and names on the part.
The design and fabrication of the Business Card Holder can be achieved through several methods. The particular method outlined in this paper was selected because it would ensure maximum utilization of the skills acquired throughout the course of the semester. For example, the use of two different CNC machines would improve students’ understanding of machining and the various machines used in the industry. Also, I have learnt the importance of documenting and revising every step in manufacturing processes in that it enables the repetition of a procedure with the same results being obtained every time. I have also learnt that a good report must be clear and accurate, so that anyone with basic knowledge in manufacturing can re-create the same part with high precision.
In carrying out the machining operations, I would recommend the checking of all blades and tools to ensure that all of them are sharp and in good working condition in order to guarantee a high quality of the finished surfaces. Also, it should be ensured that all the speed and feed rates are set to the specified values in the setup sheets before cutting or machining. The engineer or the technician must ensure that the machine set up and assembly at the home location is set as specified in the setup sheets for each operation. Also, all tooling and height numbers must correspond to the values in the setup sheets. During inspection, any inspection tool with accuracy and tolerance limits that fall within the specified values can be used.