A little NFC tag you can hang on a keyring, zipper, lanyard, or whatever. PLEASE use the 3MF file and import as project! I'll explain, but you'll have a much less fun time if you don't.

For this to be useful at all you need 25mm NFC chips, such as NTAG215. They're about .2mm thick, with a couple bits sticking up more- so the cavity is 25.6 x .4, to allow a tiny bit of room.

Why the 3MF file?

I've added a pause at layer 12 so you can add the NFC sticker/chip to the model.
The letters and signal graphic are separate objects and are aligned. (See further notes if curious).
The cavity for adding the chip will print correctly, which may not happen if importing the STEP file (or an STL).
There's 16 plated, ready to go tags!

Setting the model up correctly in the slicer was a little tricky. It turns out if you import a STEP file with a hollow section or body cavity and split to objects the slicer will create an object for the cavity- which will of course fall to the bed once split. You delete this of course, and then discover that the internal structure of the body is not solid, and all your plans are ruined.

However, importing a file with a cavity and not splitting it will result in the desired outcome- the slicer leaves the cavity alone. Great, but there was another snag. The most crisp results of multi-color printing on the plate come from adding a very small gap between colors, and in testing, actually importing as separated bodies. So what this means is that tag which will become object once printed is processed as 17 separate objects. Why add this complexity? I've found that doing this effectively eliminates colors bleeding together, and sharpens the edges of the design or text considerably.

Have a look at the photos for proof, or head over to my Instagram, Youtube, or WeChat for microscope proof.

NFC Tag Keychain

Must add a pause at layer 12!

0.2mm layer, 2 walls, 15% infill