Mamiya 16 series subminiature cameras

Film cartridges for the Mamiya 16 series are quite rare. Sometimes the cameras come with a used cartridge inside, but more commonly the cartridges are thrown away before the camera is sold. Even if you have a cartridge, you often want a few more.

Thankfully my 16 Automatic came with some cartridges – so I measured and modelled them in OpenSCAD. Now with a 3D printer, some sticky-backed black felt (I used Fablon Velour) and these STL files, you can make your own cartridges!

These files are available from Thingiverse or Github.

• Mamiya16_Base.stl (source: Mamiya16_Base.scad) – the cartridge base
• Mamiya16_Lids.stl (source: Mamiya16_Lids.scad) – the two lids for the cartridge
• Mamiya16_Spool.stl (source: Mamiya16_Spool.scad) – the take-up spool

These need to be printed at 0.1mm layer height. I used a 0.3mm nozzle which proved to be sufficient, but you may wish to use a smaller nozzle to improve the fine detail.

I've successfully printed these in ABS using a Solidoodle 2 Pro, and in black PETG using a Creality Ender 5 Pro. I recommend PETG as it is much less likely to warp, is more dimensionally accurate (less shrinkage), and in general prints better.

1. 3D printed models – see above
2. 2x pieces of sticky-backed black felt (e.g. Fablon Velour), 65mm long and 16mm high.
3. Black electrical tape
4. Optional

1. Print all three STL files. These should be set to 0.1mm layer height to reduce the risk of light leaks. (You may wish to smooth the print afterwards)
2. Install the light trap:
   1. Cut two pieces of sticky-backed black felt (Fablon Velour works well), around 65mm long and 16mm high.
   2. Remove the sticky back from the felt and fit it through the film slot, back into the cartridge and out the other side of the film slot. Leave a small overhang (a few millimetres) on both sides of the slot.
   3. Make sure the felt doesn't extend out of the slot and around onto the outside of the cartridge.
3. Check the cartridge fits together (all parts should be a smooth sliding fit):
   1. Fit the take-up spool into the cartridge body
   2. Put both lids onto the body
   3. While squeezing each lid down, apply a piece of adhesive tape (Scotch tape, Kapton or black PVC tape are all suitable) across the gap between the lid and the body. Repeat this for the other lid.
   4. Using a suitably sized screwdriver, check that the lid rotates easily.
4. Disassemble the cartridge and load it with film.

1. You will need all the parts of the cartridge: the take-up spool, cartridge body and the two caps.
2. Remove any residual tape or glue from the cartridge components.
3. Replace the light seals (each is a 35mm long by 5mm wide piece of sticky-back Velour)
4. In complete darkness, or a camera changing bag:
   1. Cut a length of 16mm-wide film, 16-18 inches long.
      • You can use a film slitter to cut a 35mm or 120 format film down into 16mm strips.
      • A 36-exposure roll of 35mm film is around five feet long – giving three strips of Mamiya film per 35mm cartridge.
      • Make a measuring-stick of the right length - this will make it easier to cut the film down in the dark.
   2. Use a strip of thin tape (9mm wide, around 30mm long – film splicing tape is best for this, but masking tape or Scotch tape will also work) to attach the end of the film to the take-up spool.
   3. Wind the other end of the film into a tight spiral.
   4. Load the tight spiral into the “source” cavity and place the take-up spool on the hub in the take-up cavity.
      • The film should be just starting to wind onto the take-up spool.
   5. Put both of the end caps on the cartridge and tape them down.
5. Remove the cartridge from the dark and load it into the camera.