Introduction: Minox 9.2mm Film Slitter
I recently acquired a Minox B "spy camera" from the 1950's--the old push-pull "slip & slide" camera from the cold war era James Bond films and Hogans Hero's reruns. Film for these old oddball formats is very hard to find and expensive. Thankfully I found 3 old cassettes at a thrift store for $2.99 and they are easily reloaded. The plan here is to slice down a roll of 35mm film into 2 9mm wide strips and discard the sprockets. You can buy one all made from a low of $50 to as much as $150 or make this one for about $2 worth of stuff
Roughly a 4x4" piece of hobby balsa wood 1/8" to 1/4" thick
a 1 1/2" wide by 4" length of 1/8 to 1/4" of same hobby balsa wood
2 1/4" square pieces of balsa wood 2" long each
3 single edge razor blades
small square of styrofoam
duct tape or black cloth tape
toothpicks for directing glue
Piece of old 35mm film as a gauge
Obligatory Cautionary & Safety warning:
You are working with and will be using razor blades--at times in a totally dark room. Please exercise all due caution
Step 1: Layout
Take your 4x4" base and center where your "trackway" will go. Use a scrap bit of 35mm to lay this out. Use the pen/pencil to outline the area of the film.
Once that is done measure 18mm from one edge of the outline and put a mark at the edge of the board.
From that center mark measure 9mm in both directions and mark the edge of the board. We now have our 3 cut marks where the razor blades will go.
Take your hacksaw blade and make cuts approx 1" in from the edge down the 3 marks
Step 2: Glue Razor Blades in Place
The blades should be mounted at angle so that the end tips protrud from what will be the top like 3 shark fins.
I used a paper plate to put a glob of glue on then used toothpicks to apply to the back of the blades. Avoid getting glue in the top trackway.
Glue the small square balsa wood edge guides in place on the outside measurement lines from the 1st layout step
Step 3: Make Top Cover
I used a small piece of styrofoam packing material & cut out a 1.25" piece less than 1/4" thick and glued it to the other strip of thin balsa wood you see here then covered it with black tape. This pad & spanner board serves 2 purposes: It holds the film down in the track to ensure even cutting and as a guard to cover the blades so you don't get sliced along with the film.
Step 4: How It Works
Take a roll of 35mm film. In roomlight get it all setup. Pull out some leader and have a tab you can hold with thumb & forefinger past the right edge. Place the film on the blades so that each tip pokes through the film. Place the top crosspiece over the channel. Now turn off all lights (room should be totally dark--use a bathroom or closet). Use one hand to hold the top in place and the other to pull slowley on the film making the slice. Pull about 1 foot of film or so.
Discard the cut-away sprockets. You now have 2 cut strips 9mm wide and about a foot in length
Step 5: Load Your Cassette
Pop the one side off and roll up the film leaving some hangng out. put the cap on that end. Pop the cap off the take-up side and tape whats hanging out to the little core drive piece- get the film into the little light tight slot and put the cap on the take up side--you are ready to shoot.
NOTE: when you start the film in the slitter some of the leading tab area will be fogged. When I'm done slitting and go to roll the pieces into the film holder I roll up the film so the fogged area is coming out first to be attached to the drive-side of the cartridge.
Step 6: Sample Scan From My Reload
I made a cardboard carrier for my el-cheapo capture scanner and got this from the film I reloaded and processed.. I retried it with my 35mm Dimage scanner and got overall a better quality scan but a weird lighter edge on the top of the frame (which was one edge side of the film scanning down ) --I'm still investigating why this occured