I have some single parts with holes drilled at specific locations but in equal increments. The whole unit had to be split up but it wasn't perfectly symmetrical so the hole patterns differ from part to part. We are getting one section ready to be dry fit so I sent off one part to be machined and we found that Microvellum had flipped the part at some point during processing. The material has a good face and it essentially flipped the part to the wrong face making it unusable. Ideally, we wanted to run all these parts with the good face up so any potential tear out from onion skinning would be isolated to the non-visible face. As such, I modeled each part individually, face up, flipped and mirrored as necessary for tops and bottoms and labeled them so no one got confused. Short of purposefully renaming them all reversed from the actual model, not sure what to look for here. 

I've checked various places and can't find a setting to prevent this. I also don't get a message about flipping for Face 6 machining since the holes are drilled through. Any ideas where to start?