35mm motion picture 100' development reel

thingiverse

This is a work in progress of a 100' 35mm development reel. I scaled up the design from a smaller version that worked great (approximately 60'), keeping the same slot size and core dimensions. To accommodate just over 100', I added more spirals to the design. Unfortunately, I don't own a printer capable of printing this size, so you'll need to experiment on your own with detection of thin walls and other settings in your slicing program. I made adjustments to the core to make it easier to spool film onto the reel at the start, but these changes are untested at this time. Additionally, I'm aware that the struts radiating out from the center may be too widely spaced as they approach the outer diameter of the reel. If you encounter this issue during printing, please let me know so I can make adjustments to the design. In the future, I plan to work on designing a spindle that accommodates 16mm film as well. This should be relatively straightforward, requiring only a few measurements and modifications to an existing design. However, due to current circumstances, this project may be delayed for several weeks. UPDATE: 6/6/2020: To fit the reel into a standard 5-gallon bucket, I modified the design to keep the overall diameter under 255mm. I reduced the wall thickness by 0.1mm while keeping the groove size the same as before. This change needs to be tested to ensure it doesn't create development issues related to holding film too close together. I increased the top lid thickness to 2mm and made the spindle collar 2mm taller to match. A small lip was added to the outer edge of the lid frame to aid in keeping the last bit of film in place. I also adjusted the notch at the inside of the main dev to make it easier to start with the film. Measuring the inside of the spiral to the notch for the central core revealed a distance of 99.93 feet. 6/6/2020 II: To further modify the pitch of the spiral, I reduced it by an additional 0.1mm, making it 1.5mm instead of 1.7mm while keeping the 0.4mm slot size. This change should allow for up to 106.4 feet of film. However, I'm cautious about going any shallower with the slot, so this will have to suffice for now. Later, I plan to work on a 16mm version of the spindle, and after receiving feedback from people who can print larger than 255mm x 255mm, I may make further modifications. I also loaded an alternative lid frame with additional support. 6/10/2020: An error in the main dev1 was corrected. Although this change is still unproven through actual printing by me at this size and iteration, there may be some minor issues that need to be addressed. 7/8/2020: I noticed a slight error in the CAD file of the spindle and cleaned it up a bit. The updated file is now called 35spindle. I also created a preliminary design for the 16mm spindle (16spindle), which mainly involved subtracting 19mm from the existing design. However, this has not yet been printed or tested. In the future, I plan to create a smaller dev and lid frame that can fit on a Prusa printer, allowing more people to print it. This version will likely hold around 70 feet of film.