Professional film cameras and accessories are often mounted on 15mm rails. This allows for much greater flexibility in adding parts because everything is made to work with the standardized rod system. Things like follow focuses and lens hoods are made to work with the rails.

For this project I designed a 15mm rail mounting block with holes all around which can be used to add anything with a standard mounting bolt to an existing 15mm film rig.

Construction

The nuts have to be embedded within the model so the block was constructed out of two 3D-printed pieces which are superglued together afterwards. PLA bonds together nicely with CA glue, so the block keeps its structural strength.

The bottom piece looks like this:

A total of six ¼ nuts and three ⅜ nuts fit in the bottom piece with spacers. The two slots on the top left and right hold an M4 nut for the thumbscrew.

The spacers stop the smaller ¼ nuts from rattling around.