6x12 Pinhole Camera v2

thingiverse

Update 2018-05-16: First prototype prints for testing the removable insert and the winder/clutch/knobs are complete. The viewfinder has been added and modified body cover to accommodate it. Update 2018-05-02: Caution: Initial knobs do not fit - they have been replaced with a new version with measurements that should fit perfectly. A tripod plate has also been added. Redesign of my 6x12 pinhole camera with curved film plane based on first real-world tests is complete. This redesign is currently untested, but I am confident it will work without issues. Most basic specs and design principles have been kept: Using roll film type 120 Format 6x12 (exposed film area is 56x116) with curved film plane 65mm focal length Pinhole diameter 0.3mm Resulting aperture about f/215 Shutter as separate module, interchangeable No light seals necessary Arca Swiss compatible tripod plate Compact and lightweight Based on the tests with the initial prototype, I decided to design a removable film insert for easier loading and polishing of film guides. Using a removable film insert required a complete redesign of the knobs/winders. The curved film plane causes friction between film and guides, so advancing the film required power and resulted in torsion of the flat winders. Now there are inner winders that stay at the film insert's top plate and outer winders with knobs that stay at the body cover and connect to the inner winder with a square clutch. The shutter from the initial prototype proved usable, so I kept the basic design and modified its base plate (now squared, allowing for wire trigger placement down, left, or right). The vignetting problem from the initial version is solved (cone with larger base instead of cylindrical hole). Using a large shutter module base plate will allow different shutter designs and addition of a filter holder (not yet designed). Simplification of light traps between body and cover. Tolerances seem tight enough to give up on inner light trap, making closing easier. Missing pieces: Two sheet metal springs that press against the film and prevent it from unrolling are missing. I won't make an extra design for this, as it's just a piece of sheet metal to be bent into shape and screwed into the slot in the film insert. You will notice that I am working with tight tolerances, especially when printing with 0.2mm layers or larger. Be prepared to use sandpaper or a file to make parts fit together. This approach works better for me than parts wobbling around. If you find any mistakes or misconceptions, please leave a comment so I can improve my designs.