a6000 Sony NEX macro tube for K mount Chinon

This is a simple macro tube adaptor for a 50mm f/1.7 CHINON manual lens.
As I do not like using plastic parts close to the APS-C sensor, I use a cheap 49mm Macro Reverse Adapter Ring for Sony NEX E-Mount which fits inside the A6000. This piece is screwed inside a 3D printed interface into which is inserted a piece of 45mm pvc tubing.
At the other extremity, there is another 3D printed part fitting the pentax K_mount I get in my CHINON lens

see the video for further details. http://youtu