One of the components inside the adapter is a mirror to allow more light through and it causes the image to flip horizontally therefore is needs to be flipped the right way round.

The mirror reflects light into the adapter removing hotspots and vignetting. I have tried to use more mirrors to get the image to flip completely but it has proved to be a nightmare.

Has anyone else tried mirrors?

hows the digi35 coming along... Any pictures with cameras mounted to it? Or footage?

Yes. Me, - when prototyping a prism version to make sure the path worked first before I bought prisms in.

Quyen Le's Letus35 flip versions use surface coated mirrors in a stout plastic case. Why not investigate his flip module rather than engineer your own. He might cut you a deal on a batch of them, who knows. It would standardise at least one part of the process.