Keep in mind your feed rates when working with copper and acrylic AND you MUST have the proper endmills to work with acrylic or you WILL end up breaking them.
Usually two flute standard endmills will work... but you will experience some chipping if the feed rate is too high.
They make endmills specifically designed for acrylics, try and get some for that.
I have machined acrylic, but I use a manual mill, so I can adjust my feed rates by feel.
Hope that helps you out KyuZo.