TigerPOD

Purpose

The first “CD player” for smart filament spools. TigerPOD puts a spool scanner on your desk — and you print it yourself. A free, open-source 3D-printable stand holding two USB NFC readers facing each other: place a spool, it identifies itself in Tiger Studio; place a blank chip, encode it. As natural as tapping a phone, but hands-free on the desktop.

A TigerPOD on a desk, a red filament spool resting on it

Put the spool down; it introduces itself.

Get a TigerPOD Print it — free STL

Sources

Why two readers, facing each other

This is the whole point of the shell, and the one thing to get right. We recommend two readers, always. One reader technically works, but it degrades the experience in two concrete ways:

Reading. A spool carries two chips, on opposite faces. With a single reader, a spool that lands the “wrong” way round has to be picked up and flipped before it is seen. With one reader on each side, whichever way you drop the spool in, a chip is already in front of a reader. Nothing to turn, nothing to aim.
Writing. When you tag a spool yourself, you write both chips. One reader means two passes, and two chances to mismatch them. Two readers write the pair in one go, and Tiger Studio can verify them against each other.

The Pod exists to hold that geometry: two readers, upright, facing, at spool distance. Everything else is a shell around it.

Where it sits

flowchart LR
  TAG["Spool / blank chip"] -- "placed on" --> POD["TigerPOD<br/>2× USB NFC readers, face to face"]
  POD -- "USB" --> ST["Tiger Studio"]
  ST -- "spool auto-opens · guided writes" --> YOU["You"]

Two shells to print — both free

	TigerPOD Mini — recommended	TigerPOD (original)

Prints	Faster, less filament	Longer, more filament
Desk space	Less	More
Cables	Routed inside the shell	External
Tags	TigerTag and OpenSpool (NDEF)	TigerTag and OpenSpool (NDEF)
Download	MakerWorld — TigerPOD Mini	MakerWorld — TigerPOD original

Both hold the same two ACR122U-class readers facing each other. The Mini is a redesign of the original and is simply the better Pod: start there unless you specifically want the larger cradle.

Licensed CC BY 4.0 — remix and adapt freely.

What it is made of

The STL is the shell; these are the parts that go inside it. Nothing here is exclusive — any ACR122U-class reader and any USB-C splitter work — but this is the combination the shell is designed around:

Part	Quantity	What it is
TigerTag Player	2	The USB NFC reader — an ACR122U-class device. One per side, so both of the spool’s chips are reached in a single pass.
TigerTag Spliter	1	USB-C to 2× USB-A, so the two readers reach the computer on one port and can be programmed in parallel.
The printed shell	1	Mini or original — see above.

Getting the parts

The shell is a free download; the two readers and the splitter are the part you buy. They are sold as a bundle, which is the cheapest way to end up with the right pair:

TigerTag Player Bundle — 2 readers + Spliter (Atome3D)
Also available on tigertag.io

Note: assembling one yourself and buying a pre-assembled one lead to exactly the same device. Any two ACR122U-class readers will do — the bundle just saves you sourcing them separately.

Build one

Print a shell — the Mini or the original, above.
Get two ACR122U-compatible readers, from any shop you like, and a pack of blank NTAG 213 / 215 / 216 chips to write on.
Slide one reader into each slot — no screws, no glue, no wiring.
Plug both into your computer. A splitter makes it one cable; two USB ports work just as well.
Install Tiger Studio — it picks the readers up on its own.

Rough budget, sourced separately — prices vary by shop and region:

Part	Qty	Approx.	Where
ACR122U-compatible NFC reader	2	€15–25 each	Amazon · or any shop
Blank NTAG 213 / 215 / 216 chips	1 pack	€10–20 — two chips per spool, so a pack tags many	Amazon · official chips
The printed shell	1	filament only	MakerWorld, above
USB splitter (2× USB-A female → 1× USB-A male)	1	€5–10, optional	Amazon

Some links in this table are Amazon affiliate links: as an Amazon Associate, TigerTag earns from qualifying purchases, at no extra cost to you. It helps fund the open protocol. Buying the same parts anywhere else works exactly as well.

Buying the kit instead costs less than sourcing the same parts one by one, the readers arrive carrying the project’s official logo, and it funds the standard — one of several ways to support the project. But building one from generic parts is not a lesser path — it is the same Pod. That is what an open protocol means.

Reader compatibility

The ACR122U speaks PC/SC, the OS-level smart-card standard every reader of this class implements. Because the Pod builds on PC/SC rather than on a vendor driver, the same setup runs on Windows, macOS and Linux, and any PC/SC library can drive it.

Features

3D-printable shell — free STLs on MakerWorld, in a Mini and an original size.
Houses two ACR122U-class USB readers, face to face (read + write stations).
Plug-and-play with Tiger Studio: scanning a chip auto-opens the matching spool; the guided chip-update flow uses it for UID-checked writes.
Not locked to TigerTag: the same two readers handle OpenSpool (NDEF) tags as well.

More than TigerTag — a universal NFC station

The Pod is not locked to the TigerTag protocol. It is, quite literally, two standard PC/SC readers in a spool-shaped holder: anything an ACR122U can do, the Pod can do.

You control the chip completely — read what is on it, write something new, change what is there, erase it back to blank. All four, in both directions. No write-once, no one-way street, no vendor lock. And for filament that happens in Dual NFC, both chips of a spool handled together, on any brand’s spools.

The ACR122U handles far more than NTAG: ISO 14443 Type A and B, MIFARE (Classic 1K/4K, Ultralight, DESFire), FeliCa, Topaz/Jewel, and NFC Forum tag types 1–4. Whatever you can read or write with an ACR122U, you can read or write in the Pod — including OpenSpool tags.

That is also what makes the second life real. A TigerTag is never write-locked, so when a spool is finished you can erase its chips and rewrite them as fresh TigerTags — or turn them into something else entirely: a plain NDEF tag for home automation, a Wi-Fi hand-off, a URL, a business card. And back into a TigerTag whenever you want. The chip is a reusable asset, not single-use packaging.

Interactions

With	How
TigerTag chips	Read / encode / verify — both chips of a spool at once
Tiger Studio	Instant spool identification, chip promotion & update

In pictures

The TigerPOD with the desktop and mobile apps