SpoolTag Manager

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Why SpoolTag Manager

Spoolman is a great inventory for 3D printing filament. It knows every spool, its filament, its vendor and how much is left. The catch: it only knows what someone tells it.

Keeping it right by hand means putting the spool on a kitchen scale, subtracting the empty spool, finding the right entry among dozens of similar black PLA rolls and typing in the number. That is tedious enough that it does not happen, and after a few weeks the inventory and the shelf no longer agree.

The idea

A small station on the shelf: a scale, an NFC reader/writer and a web interface, talking directly to Spoolman.

  1. Put the spool on the scale.
  2. Hold its tag to the reader.
  3. The station finds the spool in Spoolman and updates the remaining weight.

The gross weight comes from the load cell, the empty spool weight from Spoolman, and the difference is the filament that is left. If Spoolman does not know the empty spool weight, the station does not guess: it asks.

Tags that are already on the spool

Many spools already carry a tag. Bambu Lab spools come with one, and open formats like TigerTag and OpenTag3D describe the filament on a cheap NFC sticker. The station reads Bambu Lab tags and reads and writes TigerTag and OpenTag3D. A blank NTAG sticker becomes a new spool in Spoolman and a TigerTag on the spool in one step.

A few rules from the start

  • Spoolman stays the only inventory. The station finds, creates and links spools. It does not keep its own database, and it never edits filaments or vendors behind your back.
  • No cloud. The station runs on your own network. The browser talks to the station, the station talks to Spoolman (and optionally OctoPrint). There is no app and no account.
  • Tags are written carefully. Bambu Lab tags are never written. Every write is shown first, with the format, the spool and the filament, and runs only after you confirm it. A tag the station does not recognise is never overwritten without an explicit action.

The next post is about the first test stand: a development board, a reader, a load cell and a lot of jumper wires.

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