What's Actually Inside a £12 Label Printer

I bought this to label drawers. I opened it because the app wanted an account, and a device that wants an account to print the word "FUSES" onto a sticker has made itself my business.

Eleven screws, four of them under the feet

Nothing is glued, which is a better start than most things at this price. Four screws under rubber feet, four around the battery bay, three inside the cartridge door. The shell separates cleanly and the ribbon cable is long enough to fold the halves open like a book without unplugging anything — a small courtesy that costs the manufacturer nothing and that plenty of far more expensive things do not extend to you.

The good part: the stepper

There is a proper little geared stepper driving the platen roller, and it is nicer than it needs to be. Even steps, no perceptible backlash, and a standard four-wire interface. This is the single most salvageable thing in the box. It has since been driven by an A4988 and is currently the feed mechanism on something else entirely.

The expensive part: the thermal head

The print head is a thin-film linear array — 96 tiny resistive elements across the width of the tape, each of which heats up in a few milliseconds to darken one dot on the paper. It is unquestionably the priciest component in the machine and probably costs more than the shell, the battery, the board and the motor combined.

It is also why these printers are cheap. The head has a finite life measured in kilometres of tape.

The cynical part: the cartridge

The tape cartridge has a small IC in it. Not a memory chip storing calibration data, which would be defensible — an authentication chip, whose entire job is to answer a challenge so the printer will agree to print.

The machine cost £12. The official cartridges cost £9 each. You are not buying a printer, you are buying a subscription with a plastic housing, and the eleven screws are the only part of the transaction that was honest with you.

Third-party cartridges exist and the chip has been cloned, which tells you what the market thinks of the arrangement.

Verdict

Worth taking apart. Not worth buying twice.

Salvage the stepper, salvage the 18650 and its protection board, salvage the two microswitches. Bin the mainboard — it is a blob-on-board with no exposed programming header and nothing you would want to reuse.

For labelling drawers I now use a thermal receipt printer with no cartridge, no chip and no account, which takes 57mm rolls that cost about thirty pence. The tape is not as pretty. The drawers do not seem to mind.