As shown previously, Aluminum is a relatively soft metal, and it can be milled easily. This time, it is a 4 in. x 4 in. sheet of aluminum. I simply used a previous dxf file created for milling plywood, and reused the same gcode.
The process took only about 30 minuted to mill, and the output was clean, even though I had used a 1/16 in. ball end mill tool. Had I used a smaller sized tool, it would have been much more precise, but it would have definitely taken hours to finish the job.
Here is the time lapse video of the process. There is a bit of engraving at the end, but it is not very satisfying. I will make another one showcasing the engraving soon.