Bronica Instax Mini Adapter

This project is very DIY, contains little to no documentation whatsoever, and was done over one drunk weekend. As such don't expect 0 cludge factor until I have had some time to revisit this with some sense of sobriety.

Cut everything out of an instax mini 7, leaving essentially just the film holder. Hotglue everything together into the housing. The film ejector was made by taking out the original metal film ejector, flattening it slightly (not the angle the interacts with the instax film, but the side that is originally bent to be flat against the film housing). The film extractor is then glued to the "thumb slider". To get the extractor to engage with the film requires some finagling, but once you get the feel for it, it's not too bad.

The top film holder brackets are made from US pennies that I cut, bent, and filed to fit in the rectangular holes in the model and similar dimensions to those found on the original Bronica film back. It is not the most ideal solution, but Zinc is still stronger than a 3d printed tab and during testing I broke a tab and got it stuck in my camera, requiring minor disassembly to extract.

CHECK FOR LIGHT LEAKS WITH A BRIGHT FLASHLIGHT. Cover everything in electrical tape until you are satisfied. You can see from the sample photos I've had some light leaks in the bottom left of the film, and electrical tape+foam resolved it in short order (this is most likely from the gap required for the film extractor).

If you have any questions I will try and answer them here or on the original Reddit link LINK TO REDDIT POST.

The distance from the film plate and the bronica typical film plane was measured about 0.4mm difference, but in practice using the camera I was able to hit focus without film plane adjustment.

Best of luck tinkerers.