Purpose
The tool allows users to wind standard 35mm film into 120 backing paper. This enables shooting 35mm film in medium format cameras to achieve a wide-angle, panoramic effect that includes the film sprockets.
Design and Materials:
The main body parts are 3D-printed using PLA for stiffness. Functional components like the lock/brake and shaft are printed from PETG to provide necessary flexibility and prevent cracking. The assembly is screwless, relying on friction fits and snapping mechanisms.
Key Features:
Ratchet Mechanism: A one-directional sprocket creates “clicks” during rotation, allowing the user to count frames and measure film distance by feel while in a dark bag.
Locking Brake: A flexible pin acts as a pressure stopper and tensioner to ensure the film winds tightly and remains aligned. Alignment Windows: Integrated slots on the back allow the user to see the frame numbers on the backing paper during the initial setup.
Operational Workflow:
The 120 backing paper is loaded into the jig and secured. The 35mm film canister is inserted, and the film leader is taped to the backing paper. In a dark bag, the user winds the film onto the 120 roll by counting the clicks of the ratchet. The film is cut, taped down, and the completed 120 roll is ready for use in a medium format camera.
Files for download
Design as a step file you can find on my ko-fi webpage
It’s preferable to print from PETG mechanical parts like sprockets and shaft. From PLA you can pring outer shell and knob.
Overview of function and design and discussion of the concept
Functionality overview and main principle discussed in this video