Creating a 3D camera adapter for standard camera.

I saw online the only 3D adapters I can screw on my camera cost $150 and up which seems overpriced since only after I take the pictures I have to crop all images twice and have likely lost 3/4 of the image size. I would like to 3D print the frame for this adapter and go to a glass cutter to cut first surface mirrors for me and screw it on using a polarizer filter lens. Any suggestions or research on the angles I'll need to know for setting the mirrors?

 

I don't understand why you have to crop the photos when using the screw on adapters. I use the Pentax adapter and only crop if i want to cut something out. I view them on my computer and i also make stereo view cards to view with the old hand viewers. I also have a loreo adapter that replaces my lens. In the film days i used the Pentax slide viewer that came with the lens adapter which worked fine, and some times shot film and printed in the dark room( one of my senior projects in collage was infrared 3d nudes that earned me an "A" as the professor had never seen it done before).

I would like to find away to replace the mirrors on one of my Pentax adapters as it is scratched.

I agree does any body use this forum?

 

Shot 2 weeks ago. Pentax 3d adapter.