Zachary Houser
Manufacturing Exploration
While attending Berkeley, I enrolled in a manufacturing techniques class and we undertook 3 projects to explore and get a feel of the advantages and limitations for various processes. The processes the professor chose for us were: 3D printing, water jet cutting, and CNC mill machining. We were given free reign over what we would design to complete these and my team chose to do the create what are in the images on the left. Take a look below to see more!
3D Printing Project
The purpose of this project was to demonstrate the abilities that are inherent to the process of rapid prototyping, specifically the fused deposition modeling (FDM) of plastic to create physical models from digital drawings done on computer-aided design (CAD) software. To demonstrate the advantages of rapid prototyping, we designed and assembled Theo Jansen’s Strandbeest, an assembly of 8 unique linkages which interact to mimic a walking animal, in Dassault Systèmes’ SolidWorks, then carried on to be printed via FDM machines. Besides testing the limit of rapid prototyping with FDM, the other motivation for selecting the Strandbeest for rapid prototyping is to quickly confirm the mechanical theory behind its design. You can see all of our drawings for each part in the gallery.
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Unfortunately, our Strandbeest did not survive the Rapid Prototyping process in one piece, which you can see in the last image. Immediately after it was removed from the bath that dissolved the support material, the connecting rods that joined the limbs broke apart. Furthermore, despite providing sufficient theoretical space between the drive axle and clearance hole, the printed axle was fused with the hole for one of the axles.
There are several factors that can be attributed to these flaws. Despite meeting the minimum thickness requirement of 2 mm, the connecting rods snapped because they were printed with hollow instead of solid centers to save on material cost. Thus, after the support material was removed, the connecting rods were unable to support the load of each leg. The fusion between the main drive axle and the clearance holes may have been caused by set-up or printer error.
Despite numerous flaws, there are several aspects of the printed Strandbeest that were functional and met our expectations. Each individual limb was printed well and remained intact. In addition, the surface and edges of our parts are smooth with minimal burrs. Furthermore, the letters and decorations we added on the limbs have decent quality.
Render of what the Beest would have looked like if it had not fallen apart
Water Jet Project
The objective of this project was to obtain a better understanding of how to manufacture with water jet machining. Water jet machining is a subtractive method of manufacturing, removing material where necessary to fabricate a complete part. The process is computer controlled, allowing the water jet to create intricate and unnaturally curved parts. In order to demonstrate the functionality of water jet machining, a dragon-shaped bottle opener and an elaborate crest were machined, which were intricately detailed and contained complex internal features. These designs were ideal for the water jet machining process.
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Having followed the dimensional constraints and requirements of the interior rounds being no smaller than .04 inches in diameter and hole sizes being no smaller than .06 inches in diameter, these parts came out exceptionally with smooth faces and no edge deformation; they matched the 3D CAD very closely. In addition, the bottle opener operates flawlessly and repeatedly, as demonstrated in below, and thereby achieved our initial goal to create a functional part. Both parts did however have coarse side edges where the pieces were cut out. This can be attributed to the material nature of the water jet abrasive.
CNC Machining Project
The goal of this project was to explore the capacities of the 3 axis CNC milling machine. We decided to create the likeness of a Formula 1 racecar to do so. We tried to include as many aspects as we practically could to see how it handled each feature.
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In our finished product, as seen here, came out very well except for some flaws. Most notably, the pockets to separate the wheels did not turn out due to tool size limitations. Other than that, the flaws were minor and easy to correct with post-machining processes.
