SD Card Holder macOS Folder Style

A little folder for your SD and microSD cards – hinged, magnetic and shaped like the folder icon on your desktop. Three sizes. Still a prototype, so tell me what you think!

I've printed a few of these and they work nicely, but I'm still fiddling with the tolerances, the magnets and the hinge. If you print one, I'd love to hear how it went: drop a comment or post a Make. Too tight, too loose, a layout you'd like to see? Let me know and it'll go into the next version.

If your SD cards live loose in a drawer or rattle around the bottom of your camera bag, this one's for you. It's a tiny folder that looks just like the folder icon on your computer – so your real-world files finally get a proper home too.

The two halves are joined by a simple pin hinge, and a pair of magnets snaps the folder shut. The lid holds the cards in place, so nothing falls out when you open it. Every pocket has a little finger notch, so getting a card out is easy.

There are three sizes to choose from:

• 1 × SD + 2 × microSD small enough to live in your pocket or camera bag

• 2 × SD + 2 × microSD  the one most people will want

• 4 × SD + 6 × microSD for when the card collection has got slightly out of hand

Whichever you pick, you only need two magnets (10 × 2.5 mm) and a bit of 1.75 mm filament for the hinge pin. 

Why you might like it

• No screws, no glue – just a filament pin for the hinge

• The magnets get printed in, so they can't fall out

• Same pause height for both halves and every size

• Prints flat, no supports

• A cut corner in each SD pocket shows you which way the card goes

• 3MF files with the magnet pause already set up, plus STLs if you'd rather slice it yourself

Technical specifications

Height includes the folder tab. Details common to all variants:

• Construction: two halves, each 4.2 mm thick (8.4 mm closed)

• SD pocket: 24.4 × 32.4 mm, 2.4 mm deep (for a standard 24 × 32 × 2.1 mm card)

• microSD pocket: 11.4 × 15.4 mm, 1.3 mm deep (for a standard 11 × 15 × 1.0 mm card)

• Card clearance: 0.2 mm per side

• Magnet pocket: Ø 10.2 × 2.7 mm, top of pocket at Z = 3.6 mm, 0.6 mm of plastic over the magnet

• Hinge: Ø 2.05 mm hole for a 1.75 mm pin, 0.4 mm clearance between hinge knuckles, opens to 180°

Printing, assembly and files

What I printed it on: an Elegoo Centauri Carbon with PLA+ (the bio kind). Nothing about it is fussy, so any decently tuned printer should be fine.

Settings that worked for me

• Layer height: 0.2 mm

• Walls: 3

• Infill: 15–20 %

• Supports: none – both halves print flat, outside face down

• Material: PLA or PLA+ (PETG should be fine too)

Popping the magnets in

1. The 3MF files already have the pause set up. If you're slicing the STLs yourself, add a pause at Z = 3.6 mm in both halves – that's just before the magnet pockets get closed over.

2. Before you start, stick the two magnets together and mark the faces that touch with a marker. Saves a lot of head-scratching later.

3. When the printer pauses, drop a magnet into each half with the marked side facing up. That way they'll attract, not repel, when you close the folder.

4. Check they're sitting flat, then hit resume.

Putting it together

1. Slot the hinge parts of the two halves into each other.

2. Push a piece of 1.75 mm filament (or 1.5–1.8 mm wire) through the hinge hole from the side. Lengths are in the table above.

3. Snip the ends flush. If the pin feels loose, a quick touch with a soldering iron or a drop of glue on each end sorts it out.

Shopping list: the two printed halves, 2 × 10 × 2.5 mm neodymium magnets and a bit of 1.75 mm filament or wire. That's it.

In the files

• 3MF files (magnet pause included) for each size

• STL files for the front and back of each size