Version 1.1 of a film cartridge designed to fit Fuji Single 8 cameras, released as open source under the CERN OHL-S V2.0 licence.
It's a 3D-printable shell and parts for a film cartridge to fit Fuji Single 8 home movie cameras. This is a film fomat for which film was produced from 1965 to about 2010 when it ceased production, leaving Single 8 film enthusiasts without a supply of film. It is possible to load a Single 8 cartridge with film from a Kodak Super 8 cartridge, and that's what this project is intended for.
In this directory you will find two CAD files for the OpenSCAD programmer's CAD system. One contains the cartridge parts and film pulleys, the other contains the reels to hold the film. You will also find sub directories for ISO 25 through 200 containing precompiled STL files for the different versions of the cartridge. These are the files you will use for 3D printing.
You will first need the STL files from the relevant subdirectory for your film speed, or to generate them for yourself from OpenSCAD. This will leave you with a file for the cartridge, the lid, the film pulley, and the reel. The cartridge and lid each need to be printed once, while you will need two each of the pulley and the film reel.
This is a project that requires the best possible quality 3D printer you can find at the highest quality setting, in black filament or resin. Use a resin printer if you have one, if not the highest resolution FDM printer you can find. Rough prints scratch the film, your sub-$200 Chinese printer isn't going to cut it here.
If you are new to 3D printing or you don't have a good enough printer, I suggest that you use an online 3D printing service. This is what I did for my final prints, and the extra quality was totally worth the outlay. I used JLC PCB's 3D print service for mine, and in an order of three cartridges each cartridge cost me about 16 dollars including taxes and shipping from China in autumn 2023. You will need to put each part in as a separate order item, and don't forget to order two each of the pulley and the reel. I selected the cheaper of their two matt black resin options for my print. I am not sponsored by JLC, they're just a supplier I and my friends use a lot for PCBs and this kind of work.
I suggest very strongly that you spray the outside of both cartridge bottom and lid with a good quality matt black paint. This will catch any possible light leaks, as well as giving a nice surface for the cartridge. If you have used an FDM printer, ensure the inner surfaces are as amooth as you can make them.
This is as good a cartridge as I think it's possible to make by these means, but it's still an experimental item, and requires care and practice to load correctly. Obviously any film you wish to shoot must be loaded in the dark, but it is strongly suggested that you practice with scrap or expired film in the light until you understand how it works. Make sure you know what you are doing before you load it with something you intend to shoot, and bear in mind that this is an experimental design before you trust it with valuable film.
If you place the bottom half of the cartridge in front of you with the bottom facing down and the area for the film gate facing towards you, the full reel should be on the left, the emulsion should face you, the sprocket holes should be along the lower edge of the film, and the take-up reel should be on the right.
Place the two pulleys on their shafts, in the corners closest to you.
Both reels are wound with the emulsion facing inwards, and rotate clockwise. The top of the reel has a protrusion with a slot for cameras with a rewind handle, while the bottom of the reel has the opening for the camera shaft. There is a slot in the reel for the film.
The film comes off the supply reel on the left and doubles back on itself round the pulley on the left, before passing through the film gate area with the emulsion facing you. On the right hand side it doubles back on itself again to wind on to the take-up reel in a clockwise direction.
Now we come to loading the Super 8 film into the single 8 cartridge. We are aiming to load half a Super 8 cartridge into each Single 8 one, so about 7.5 metres.
Wind the Super 8 cartridge by putting it in a camera and pressing the shutter button with the lens covered so no light can get it. Watch the time indicator on the Super 8 camera, and stop it half way at about the 1.5 minute mark. Take the Super 8 cartridge out of the camera and put a little bit of tape on the film, this will allow you to identify the half way point. Then put the cartridge back in the camera and wind the rest of it until its end.
Now break the non-return mechanism by turning its reel backwards with a pair of pliers.
You can now cut the Super 8 film, and reel it directly onto the SIngle 8[ supply reel.
Be very careful to ensure that the emulsion faces in the right direction - towards the centre of the reel - and the sprocket holes are along the bottom.
When you have a full supply reel you can place it in the cartridge and thread the film round the pulley, through the film gate area, round the other pulley, and onto the take-up reel. Take up any slack with a turn of film round the take-up reel.
Now you can put the lid on the cartridge, and secure it with two short pieces of masking tape at the sides. You should now be able to take the cartridge into the light, and load it into a camera.
This cartridge model is open-source, that means I have made my design freely available for the Single 8 community to print and use their own cartridges. The licence I have chosen is strongly reciprocal, this means that if you modify the design you must also release it as open source. If you distribute it or cartridges made from it you must also distribute the URL of this repository.
You can sell these cartridges, but if you do so I have something to say. The photographic world is full of profiteers, and if that's you I have something to say to you. It costs well under 20 dollars to get these cartridges printed commercially, less if you produce them in quantity, so I think 30 dollars is a maximum fair price to sell them for. I made this model as a free gift to the community under an open source licence, because I earn my money as a technical journalist. If I catch anyone selling these cartridges for silly money I promise this: I will make sure the world and dog knows about it, and I will undercut you. Try adding value by loading your cartridges with film, but even then don't take the piss.
Without the generous help and expertise of Frank Bruinsma at the Super 8 Reversal Lab in Den Haag, Netherlands, this project would have taken much longer and had many more false starts.