120 Film Scanning Holder (6x4.5 Frames)

UPDATE:

• Added v2 STL which includes slightly tweaked dimensions within the negative channel and improved magnet positioning to reduce the force required to lift the top plate
  • New channel dimensions reduce side-to-side play from the front of the channel and increase the amount of frame border supported to make it easier to position the current frame.

Print Settings Overview:

• Filament:
  • PLA
• Printer:
  • Qidi Q1 Pro
• Infill:
  • 30% but only to add weight, can probably go lower if necessary
  • Grid
• Layer Height:
  • 0.2mm
• Outside layers:
  • Perimeters: 2
  • Top Layers: 5
  • Bottom Layers: 3
• Supports:
  • REQUIRED
    • I just chose the automatic support option in my slicer (Qidi Slicer), seems like it was more than enough
• Orientation:
  • Print in the default STL orientation. If it gets changed somehow, just place the side opposite the hinge face down (this ensures the plastic touching the negative is as smooth as possible.

Extra Tools (Optional):

• Flush cutters
  • Helps quite a bit in removing support material. It was pretty stuck on for me
• Magnets (6mm diameter / 3mm height)
  • Helps keep the two halves together to really flatten the negative

Notes

I noticed that there weren't many models specifically designed for scanning 645 frames and those that did exist (that I tried) often left scratches on my negatives from dragging the film across the plastic. 

My goal was to make a holder that reduces the risk of scratching negatives without sacrificing too much of the scanning speed you get from a pull-through style holder. The idea is that you lift the top plate before sliding the film so there's minimal friction between the film and the holder, but when you drop the plate, the negative is held securely flat.

The 4 small holes on the inside faces are intended for small magnets that really help flatten the negative. They aren't strictly necessary, but my prints tend to warp slightly which makes the plates sit less flush when closed. I used some cyanoacrylate to hold the magnets in place. 

One model contains 4 circular feet on the bottom which I use to hold the holder in place on my scanning light. I'd recommend either designing something yourself to place these feet in or using the flat bottomed model to add something to keep the holder in place. Should still work if you just leave it flat, just might slide around a bit more.

Last note, the hinges are designed with a tolerance of 0.3mm between the balls and sockets. If for some reason this tolerance doesn't play nicely with your printer, reach out and I can try increasing/decreasing the tolerance and adding a new model.