Book-style SD card case

This book-style case has 5 cover options (plain, Printables logo, Prusa logo, SD logo horizontal and SD logo vertical). The non-plain versions use the print-on-print technique: print the insert first, remove purge line and skirt, print the case on the insert.

There are variants with recycling symbols for the most usual materials. Also, each combination has a “right-handed” and a “left-handed” variant: not all books open the same, do they?

How to Print - Tips and tricks

Use a 0.15mm layer height, with a 0.15mm first layer height (not the usual 0.2). It works well with a 0.4 and 0.6 nozzle, but I haven't tried any higher or lower. You might try also a layer height that is an integer divider of 0.15; that is, 0.05 or 0.075.

Set the infill angle to 90, and bridging angle to 180. (Rotate these angles accordingly if you rotate the model.) This way, you will have two layers of crossing extrusions in the spine folds. This makes for much stronger, long-lasting book hinges.

For print-on-print technique (used by the cover inserts of the Printables, Prusa & SD logos), use 0.20 layer height, 0.20 first layer height to print the inserts (but remember to use the settings above for the case).

Add a color change at layer 7 (z=1.05mm) if you want to make the "paper color" effect.

Print preferably in PETG, or something with a bit of flex.

If you're printing in regular PLA, use the 3mf files Book_SD_case_PLA_modded or 2xBook_SD_case_PLA_modded, and change the filament and printer settings according to your setup. (You can replace the STL with the right button, and add inserts at their same coordinates, as inserts are self-centering.) These files have a modifier included that adds a bit more of flex by removing the perimeters of the spine in the first 2 layers, so only the very first layer has extrusions parallel to the flexing axis (which do stiffen the spine and induce breakage; we need them to be perpendicular, not parallel). Anyway, take extra care when scoring/folding for the first time; it's too stiff. The spine modifier is available as a separate object —just remember to "drop to bed" it when loading it into the main object.

3D850 works better than "regular" PLA and usually doesn't break when using an un-modified version. “Silk” and “magic” PLA work very well (maybe it's because, they say, they have a bit of TPU on them, making it more bendable). They can look great with a bottom layer concentric infill.

PVB works extremely well, even better when smoothed with IPA. It's on par, if not better than, polypropylene.

Preparing the case

When print is finished, remove it from bed and bend just slightly, never all the way, one of the sides. Do the same with the other. Bend the first side a bit more, then the other. Keep doing this until you can close it easily. You can also try (not with PLA) to open the case wide open, and move one of the sides slightly forward and the other slightly backwards and both to each other, so the profile (viewed from the top) looks a bit like a S or a Z. Then you'll have your case perfectly scored.

The closing mechanism relies on latches but also a bit of a friction fit. It's important that the printer is well tuned. You don't need an absolute spot-on precision, but a tolerance of about +/- 0.05 on two/three wall extrusions would be desirable.

One last note (the Printables logo)

For some reason, the Printables logo may result hard to print at least in PrusaSlicer; either the triangle or the upper part of the P may be missing in the first layer. (Check out the G-code, not the PrusaSlicer preview, to make sure everything's alright.)

To avoid this, set the "Elephant foot compensation" at 0 for the Printables logo insert.