Microcassette case

This is a case for a single audio microcassette (as used in dictation recorders and answering machines, not a "compact" cassette for music).

Present features (compared to a standard commercially-made case):

• It snaps shut.
• It locks the tape reels in position to prevent unwinding due to vibration.

Absent features:

• It probably will not comfortably fit a J-card unless enlarged, and even if it were it would not be transparent like a molded polycarbonate case.
• It does not have ridges/recess to assist in pulling open the case, but I find that the printed plastic is rough enough not to need them much.

Possible improvements that could be made:

• Compact cassette version — once I have a cassette to test fit with.
• Window to reveal labeling, at the cost of less dust protection.
• Make the .scad Customizer-compatible for tweaks.

Design notes

This case was designed by measuring and test-fitting with a cassette, not by comparison with a commercially made case, because I didn't have one to compare — the motivation was that I bought cassettes that didn't come with any!

However, everything in the design was based on my memory, and images on the web, of commercially made cassette cases. It turns out there are good reasons for the various features to be exactly where they are! For example, if the hinge were located at the nice symmetrical point of as far from the end as from the large sides, then a corner would bind up just as it starts to open.

It took four revisions to get to this published version:

1. It fit the cassette but the latches did not hold at all, the reel locking pins were too short.
2. Improved the latches and locking pins, but now it was too hard to open and the latches caused the hinges to pop apart.
3. Fixed all those problems and adjusted things for a closer fit, and found that it operated well except for the binding up I mentioned above.
4. Moved the hinge pins to solve that problem.

Also on GitHub: https://github.com/kpreid/3dp-tape-cassette-case

Print instructions

The design was tested with PLA on a Prusa i3 MK3S.

This is likely to need dimensional tweaks to work well on your printer. The hinge and latch features have very close fits.

Also, the inside of the hook of the "J" is printed bridged, so the amount of sag will greatly affect how snugly the microcassette fits, but this isn't a critical dimension as long as it isn't too small.