Polaroid 110A 4x5 back

thingiverse

This is a replacement back for the Polaroid 110A to allow it to shoot 4x5 negatives with the included custom 4x5 film holder. Print the grip with supports everywhere, though you can block supports under the hinges if you like. Print the back with supports. This comes in 2 pieces for ease of printing, so they will need to be glued/screwed together, though both pieces snaps onto the back firmly. To use, remove the positive film spool on the left side of the 110A, remove both doors by removing the hinges, and install the grip, pushing the hinge pin through. If the hinge pin doesn't go in, try a thinner wire. Insert the two latch hooks into the two holes in the right side of the back with the hooks facing inwards and check the alignment with the latching mechanism. The hooks should butt up against the outsides of the back and be against the left inside of the body. Glue the latches in place, then glue the back to the grip while in place. The grip and the back should be one piece after this is all done. I taped under the joint to ensure there are no light leaks. Line the edges of the back with felt to help prevent light leaks. Check the fit of a film holder to be sure it fits OK. You will need to move the infinity focus back by drilling out the 2 rivets on the old one and unscrewing it, then screwing in the new one Check infinity focus with a ground glass and adjust accordingly. Be sure the ground glass is set back from the back as much as the film will be in the film holder (around 4mm). Cross check with focusing on something close--it should be in focus if infinity is set correctly. If it isn't, double check your ground glass offset. A custom 4x5 film holder is included. Print 2 pressure plates and the holder, then cut a 35mm wide piece of felt and glue it to the entrance. You may want to shim it with cardboard to make it thick enough to seal light. Then, tape the pressure plates in place with the thicker section at the end facing out. This helps firm up the pressure plate and provide a light seal. Cut dark slides out of bristle board and mark where the slide clears the film so you don't pull it all the way out when taking a photo. A mount for the flash is provided (remixed from Albert's excellent design) which you can screw a focused flash mount from an old camera onto. I took the louvers out of the flash to get full power all the time and calculate using a GN of 140 at ISO 100 with a hi power flash cube at M sync and 1/30 sec. An elastic strap can be made that wraps around the front of the camera top and bottom to hold the film holder in place while using.