Focus: SolidWorks Surfacing and 3 Axis CNC Machining
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The goal of this project, part of the IPD 5010 course, was to design and build a piece of desk candy using CNC machining. I chose to create a model of my pet rabbit, seen posing below. [insert a picture of Toby posing below].
This project challenged me in many ways and taught me lots of new skills. In order to create organic shapes, one cannot just extrude planes and faces. I needed to round, flowing curved lines to shape a realistic rabbit. I was new to the Surfacing tools, so the CAD went through lots of iterations. [insert early and final CAD].
Much forethought went into how to design the intricate detail so that they were machinable. The rear legs and ears had to be modified in order to avoid undercuts that an endmill would not be able to reach.
When the CAD was finalized, I had to outline a machining plan. I decided to first machine away the material around the feet and belly, using the material at the head and back as stock to hold in the jaws. In the pictures below, the squared block of aluminum is zeroed in the Haas MiniMill using a probe, then roughing and finishing passes remove the material, exposing the feet and belly of the rabbit.
With the bottom half completed, I could flip the rabbit over. I bolted the half-finished part to a fixture plate using tapped holes in the feet (seen in the left-most picture below).
The head and back were machined away in rough and finish passes, leaving a completed aluminum rabbit. The final step was to clean up the surface left over by the 1/8″ ball endmill. I could take it to the belt sander to remove most of the marks on the convex faces, but I needed to take a Dremel with a sanding disk to many of the smaller interior features. Buffing and polishing wheels created a mirror finish. The last step was to ship the aluminum part out to be anodized, giving it a hard exterior surface.[pic of rough, smooth, anodized rabbit].
You must be looking at this rabbit thinking something is wrong, and you’d be right. His ears are missing! This is intentional, don’t worry, and was done for two reasons. First, the ears are very thin and tilt backwards slightly. This would be next to impossible to machine on the 3-axis Haas MiniMill. The ears would vibrate, chatter, and possibly break. There would also be no way to reach the material underneath the ear without going through the back. Secondly, the ears are the most expressive part of a rabbit, so I wanted to be able to change their position to indicate his different moods. I did this by milling out two small holes into which each ear will fit and be able to rotate or be swapped out for different ears (such as his flat-back angry ears). The ears are 3D printed in black and are the final touch to my aluminum desk-candy rabbit. [insert final completed picture].