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Aluminum Machined and Anodized Prototype

Project Overview:

Manufacturing Process: CNC Machining and Boring
Part Material: Aluminum 6061-T6
Part Dimensions: 390.00 × 213.00 × 130.00 mm
Surface Finishing: Sanding, Tapping 1-1/2" BSPT & M12, Anodizing
Manufacturing Tolerance: ± 0.1 mm
Quantity and Lead Time: 1 Unit, 7 Days

The customer was a western Australia company offering professional service and engineered solutions for fluid systems around the world. This aluminum prototype part was made to test its liquid pressure and fitting before low volume manufacturing. Considering the big overall dimensions and multi-sided milling need, the size stability and milling tolerance were challenges for this project. In addition, one deep hole was bored as it out of milling capability, and tapping 1-1/2" BSPT for achieving sealability.
CNC Aluminum Machining   CNC Prototyping Step By Step:

Step 1: CNC machining the first side. As an subtractive manufacturing process, CNC machining cut away the unwanted material from a block of base material to get the intended part, the material block's dimensions were usually (L×W×H) 2-3 cm bigger than the part milled. To get a high CNC milling efficiency, it usually started from coarse machining by big and strong cutting tools to fast remove the unwanted material, then gradually the smaller tools to mill the fine and detailed features.


Step 2: CNC machining the second side. For the multi-sided milled part made by 3 axis CNC machining, the workpiece was rotated manually each time to mill each side, the CNC machinist must accurately relocate the workpiece to ensure the milling tolerance. 5 sides (normally 6 sides of a part) of this aluminum prototype part were rotated to be milled, and an ABS fixture (the bottom yellow one) was milled to prevent the workpiece deformation during its multi-sided machining.   CNC Aluminum Milling
CNC Milling AluminumStep 3: CNC machining the third side. The main shape of this aluminum prototype part came out after finishing the first and second side's milling that took the majority of milling time and cost for this project. The fourth side's milling work was to mill the 6 holes of the bottom side.
CNC Machining Aluminum Step 4: CNC machining the fifth side. One of the two deep holes on this final side's milling had to be CNC bored instead of milled since it was out of the milling capability by the part geometry, and tapping 1-1/2" BSPT for achieving sealability was also done by the CNC boring process.
Aluminum Machined PrototypeStep 5: The CNC milled aluminum prototype part before tapping 1-1/2" BSPT & M12×1.5 and boring the deep hole. All cutting lines and burrs on the milled part surface were removed by hand sanding prior to the further surface finishing of beadblasting and anodizing dark blue.
Aluminum AnodizingStep 6: The final surface finishing aluminum anodizing. The thin anodized film provided not only aesthetic feeling and also the better corrosion & abrasion resistance for the part anodized, different colors and glosses could be achieved by this anodizing finishing.


Aluminum Milled and Anodized Prototype   Step 7: The finished aluminum milled and anodized dark blue prototype part for delivery. After finishing the liquid pressure and fitting test, the customer proceeded with low volume manufacturing of 10 units shortly.


How to Make a Quality Aluminum Milled and Anodized Part:

• Quality aluminum material used. The anodizing result was considerably affected by the aluminum material composition.
• Quality anodizing technology. The intended colors and glosses could be matched as close as possible by quality anodizing technology.
• Quality CNC milling. Good CNC milling delivered the tight tolerance also helped get better subsequent surface finishing quality.