Im having an issue with facing acrylic on my high precision CNC.
The issue is that no matter how many facing passes I complete, there are these lines appearing in the plastic (see picture). Anyone who has ever done part facing with a CNC or a mill has probably seen these lines at some point . . .
The lines (ridges?) are so small that you cant actually feel them (feels like a perfectly smooth surface, despite how it looks).
Originally I figured they were just optical distortions because of some kind of localized thermal heating that reorganizes molecules . . . but apparently it isnt.
Normally these lines fit very much within acceptable tolerances for people, but not today . . . This facing is used for a mold for a transparent polymer (similar to as seen in picture) that cures within the mold. Strangely, when I take out the polymer after it has solidified, the lines appear in the polymer too! This is bad because I need the transparent polymer to be an exact thickness with no optical distortions for high tolerance testing.
How do I get rid of these lines?!? I have heard of some kind of buffer tool that I can use for my CNC. Anyone know about this?