Polaroid Film Conversions

Converting a Polaroid pack film camera to 120 roll film, 6X6 format

Printing up the parts

Download the 3D files here and print each of the files using supports and 3 top and bottom layers for light tightness. You can also send the an STL file with all the pieces to any print service (try Craftcloud3d for a pretty good quote in your area), or you can order them from PCBWAY which quotes around $25US for this project.

The drive gear drops in place in the top right of the cartridge and should snap in with a slight click. While the drive tab is vertically aligned, mark the top of the gear so that you can remove the cartridge later. The thumb gear installs with a thin screw or rod (an old Polaroid hinge works) through the hole in the cartridge. The film winds forward when the thumb gear is spun to the left.

Turn the door over so the bottom of the door is facing up. You'll notice 2 small notches at the left end between which the hinge is glued. Glue the hinge so the hinge loops are facing down, aligning it between the two notches. Remove the original back door by removing the hinge (you may have to remove the plastic pieces at both ends of the hinge) and install the new door. It may be tricky to align the hinge while inserting it. It would be best to insert the hinge pin into the 3D printed door before installing it, to ensure the print left enough room for the hinge. Close the door while pressing on the release latch and be sure the latch engages securely. If the latch doesn't seem to return freely, file a bit off of the bottom and tip of the latch hooks on the back. Be careful as the hooks are somewhat fragile. You can either cut/glue a red filter over the film counter hole, or you can place a piece of black tape over it to prevent light leaks through the exposure counter hole.

File the ridges off of the 2mm end shafts of the pressure rollers so it will roll freely once installed into the pressure plate. Sand the rollers with 100 grit so they are smooth but will have a little bit of friction. If they can spin while the film roll goes through, there will be less friction, though there is minimal friction even if they stop rolling.

Line the top edge of the film compartment with 2mm black craft foam to prevent light leaks from the top of the door. Alternatively, you can glue a piece of craft foam onto the outside of the cartridge, butting it up to the top of the film bay while it's installed in the camera. Then, take a piece of black hockey stick or gaffers tape and line the inside of the hinge to prevent light leaks there.

Using the 120 film holder

Place the spool adapters onto the film roll and place it in the left side of the cartridge
Thread the start of the 120 film onto the empty spool and place a spool adapter onto the bottom of the spool. While the drive tab is vertically aligned, slip the take-up spool onto the drive tab, then lower the bottom of the spool into the cartridge. It will require a little bit of pressure for it to go into place.
Place the pressure plate over the film with the writing right side up and make sure it's seated firmly.
Insert the adapter into the camera. Be sure it is firmly bottomed out in the camera.
Close the door, making sure the hooks latch securely, then, indoors or in the shade, advance the film to the first exposure.
After the last exposure, cover the exposure counter hole and wind the film until the whole backing paper is wound onto the take-up spool. The exposure counter hole needs to be covered because for some reason, some brands of film (Arista/Fomapan) place a hole in the center of the backing paper, and you will expose an nice hole in your last picture if it isn't covered.

Feel free to contact me with any questions or news about your build!