Arco Unleashed v1.3.0 (Bookworm 6.18.30)

Latest build — 2026-09-03 (v1.3.0). Five things an owner will notice.

(1) The Z offset has a button now, and it shows you what it measured. When the first layer sits too
low and the nozzle scratches, the value that fixes it is [probe] z_offset — and until now the only way
to set it was to edit a file. CAL_Z_OFFSET sits under Calibration in Mainsail and Fluidd: it
homes, parks over the middle of the bed, runs Klipper's own paper test, and when you press Accept it
offers to save. The offer names the number it measured beside the one the printer is running on,
because a value you cannot compare is a value you cannot judge. And it removes the step people miss:
Accept on its own changes nothing until the config is saved.

(2) The display no longer waits for ever before a print. It listens for one line — the one that says
bed levelling finished — and the kit's own G30 had quietly stopped saying it, on every printer, since
a profile load replaced the measurement. Starting a print from the touchscreen therefore sat at
levelling and never moved on, while the same file from Fluidd or the slicer printed fine. G30 measures
again during a print and only loads for the display's quick-level.

(3) A bug report is one file now. ARCO_SUPPORT, under Maintenance, writes
arco-support.tar.gz next to printer.cfg: the tail of the logs, your config, the kit version, which
features and guards are on, and the state of the host. A klippy.log passes 50 MB on a printer that has
been working a few weeks — more than anywhere you would post it accepts. This is about two. It leaves
other people's config files behind, blanks anything that reads like a key, and says in its own README
how many lines that was.

(4) An update no longer stops on a password prompt nobody typed. Updating over Mainsail, or fetching
any public repository, could halt asking for a GitHub username. Git's newer wire protocol was the cause;
the kit pins the older one, and the prompt is gone.

(5) Every guard can be switched off, and the switch works. The off switch had been unable to turn a
guard off since it was written — it looked at the wrong thing when it went to rename the file. Alongside
that, the TFT reprint bridge is withdrawn: it ran on every printer, fed a capture file that nothing
capped, and what it left behind is removed rather than abandoned.

Also: the manual explains the Errno 11 traceback owners keep finding in klippy.log — harmless, and not
something that can be switched off — and the Z-offset chapter says which of the two values in the
interface lasts, why the live one does not, and how to correct a measurement with Live Z instead of by
hand.

The pre-built image below is unchanged from v1.2.3. Only the documents in the archive are new. A
fresh flash therefore starts on the older kit and reaches this version the usual way — ARCO_UPDATE in
the console, or Moonraker's update manager.

Arco Unleashed — Full Image (pre-built, flash & run)

A complete Debian Bookworm + Klipper v0.13 image for the Phrozen Arco. Includes the Klipper
stack, the arco-unleashed kit (setup menu, AMS auto-mode, Mainsail theme) and the Arco configuration.
No proprietary Phrozen software is included — you supply Phrozen's official Arco_FW_V*.zip
yourself, or let the printer fetch the display module from Phrozen's own public repository once you
confirm.

📦 What to download

Asset	You need it for
Arco-Unleashed-USB.zip	everything — the image, its checksums, the self-flash tool and all guides.
Arco-Reflash-to-Buster-USB.zip	only if you ever want to go back to stock Phrozen Buster.

Two downloads, and most people need only the first. The image lives inside Arco-Unleashed-USB.zip
together with its .sha256 and .rawsize, so there is one thing to fetch and nothing to mismatch —
and collect_data_arco.sh is in there too, at the top level, for the one case that still needs it.

Flashing it

Extract Arco-Unleashed-USB.zip onto the root of a FAT32 stick — plugged straight into the
printer, never through a hub. Phrozen's Arco_FW_V*.zip is optional: bring it only if the printer will
have no internet during setup, or if you want PhrozenGo. Then SSH in as mks and:

cd ~/printer_data/gcodes/USB
sh prepare_unleashed_self_flash.sh

It unpacks the flasher — replacing whatever was in ~/selfflash, so the version that runs is always the
one on this stick — and asks whether to start it. Answer y, give your password, and take 3 —
Install. Type yes to the disclaimer and then the target device in full. Leave the stick in: the
display shows check → write → verify, and write and verify both say DO NOT POWER OFF, and both mean
it. The printer restarts by itself.

There is one hands-on step afterwards, and it is not optional: flashing the MCUs, which needs two
buttons pressed inside the toolhead. The MANUAL pictures every screen of it.

Going back

Take the backup the installer offers as menu item 2 before you flash — it images the whole eMMC
onto your stick, no teardown. Phrozen publish no stock image for download, though their support has
supplied one on request; a copy you take yourself is this printer, with your calibration, available
the moment you want it. Note that the eMMC is only half the machine: a return to stock also needs both
MCUs flashed back to v0.11, which the setup menu's going back to Buster does in the right order.

Documentation: MANUAL ·
QUICKSTART ·
README

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Arco Unleashed is an independent, community-made project. It is not endorsed, supported or distributed
by Phrozen, and Phrozen cannot be asked for support on a printer running it. Use at your own risk — this
will very likely void your warranty.