Henrik Muehe
226b44053c
The auxiliary A axis carries a tool that hangs below the Z spindle.
Beyond a small Z descent the two physically collide unless A drops
with Z. Enforce in machine coords:
A_machine - Z_machine <= K
K = (A_home_mm - z_home_mm) + couple_z_clearance_mm
With our setup K = (134 - 0) + 22 = 156. At rest A=134 Z=0, A-Z=134
which is fine. Z can descend 22mm before the rule starts forcing A
down with it.
Two complementary layers:
(1) AuxPreprocessor injection (auto-fix uploaded files)
Tracks modal Z, A and distance mode (G90/G91) while scanning the
file. When a line would put A above Z by more than the clearance
we emit a 'G0 A<safe>' BEFORE the line so A is already at the
safe position when Z descends. Endpoint check is sufficient
because Z moves monotonically along a single line.
Errors are raised (not silently auto-fixed) when:
- the line lifts A above the safe band while Z stays put
(would require auto-injecting a Z-up which could swing
through a fixture)
- the line endpoint targets an A above the safe band
G91 disables injection with a one-shot warning; the runtime
check still applies.
(2) Runtime check (ExternalAxis.check_coupling)
Single source of truth for live motion. Hooked into:
* Planner.__encode for every line block (covers MDI and
running programs - gplan emits machine-coord targets)
* ExternalAxis.execute_to_mm/enqueue_target_mm/enqueue_line
for direct A motion (covers UI jog/move and planner-A
dispatch)
Raises ExternalAxisError on violation; gplan and the API both
surface the message. Skipped when coupling is disabled or the
axis isn't homed (mirrors the soft-limit gate).
Continuous Z jog from the AVR is not gated - it's an active
operator action without a pre-known endpoint. Operator-driven
over-travel during continuous jog will be caught by the next
MDI/file-load attempt.
Configuration in aux.json:
couple_z_enabled bool default true (per agreed setup)
couple_z_clearance_mm float default 22.0
z_home_mm float default 0.0
Surfaced in the new Z-A Coupling section of the A Axis settings
page with a description of the rule. Existing aux.json files get
the new keys via the merged-defaults path on read.
Tested locally with synthetic gcode covering Z descent, combined
moves, A lift while Z deep, G92 reset, G91 mode, and combined
Z+A target violations.
OneFinity CNC Controller Firmware (W-axis fork)
This is the OneFinity / Buildbotics bbctrl firmware with a virtual W axis driven by an auxcnc ESP32 over USB serial. See docs/AUX_W_AXIS.md for the design and config.
Layout
src/avr/ AVR firmware (motion controller, AtxMega)
src/boot/ AVR bootloader
src/bbserial/ Linux kernel module for the bbserial driver
src/py/bbctrl/ Python control daemon (Tornado + websockets)
src/js/ Vue.js UI (legacy)
src/svelte-components/ Newer Svelte UI for dialogs and settings
src/pug/ Pug templates compiled into build/http/index.html
src/resources/ Static assets and config templates
scripts/ Install / update / RPi build helpers
docs/ Architecture, dev setup, W-axis docs
Build & flash (quick path, macOS or Linux)
The full build (make) requires avr-gcc, but the controller and UI
only depend on the Python + web parts. If you're shipping a UI/Python
change you don't need the AVR toolchain.
Prerequisites
- Node.js (any recent LTS) with npm
- Python 3 with setuptools
npm installonce at the project root (this is wired into thenode_modulesMake target, but on a fresh checkout it's clearer to do it explicitly)
npm install
(cd src/svelte-components && npm install)
macOS gotcha: esbuild platform pin
The Pi build leaves node_modules/esbuild pinned to
linux-arm64, which won't run on Darwin. If npm run build inside
src/svelte-components complains about esbuild, reinstall it for the
host:
cd src/svelte-components
rm -rf node_modules/esbuild
npm install esbuild@0.14.49 --no-save
(Use the version that matches package-lock.json.)
Build the web UI + Python sdist
# Build the Svelte components
(cd src/svelte-components && npm run build)
# Render pug templates and copy assets into build/http
make all # AVR step will fail without avr-gcc; safe to ignore
# if you didn't change anything under src/avr or src/boot
# Package
./setup.py sdist
ls dist/bbctrl-*.tar.bz2
make pkg is the canonical target but it tries to build AVR first. On
hosts without avr-gcc, run the steps above directly.
If bbctrl-*.tar.bz2 is missing src/bbserial/bbserial.ko, copy the
prebuilt .ko from a previous official release into src/bbserial/
before running setup.py sdist (the install script on the controller
just installs the existing module if a newer one isn't shipped).
Flash to a controller
curl -X PUT -H "Content-Type: multipart/form-data" \
-F "firmware=@dist/bbctrl-1.6.7.tar.bz2" \
-F "password=onefinity" \
http://onefinity.local/api/firmware/update
…or use the Make target:
make update HOST=onefinity.local PASSWORD=onefinity
The controller stops bbctrl, untars the package, runs
scripts/install.sh, and brings the service back up. Total downtime
is ~30-45s. Watch progress at http://<host>/ (you'll get 404s while
bbctrl restarts, then the new UI).
Verify the flash
curl -s http://onefinity.local/ | grep -c "OneFinity"
curl -s http://onefinity.local/api/aux/status # if W axis is enabled
Build & flash (full path, Debian/Linux)
For AVR + GPlan rebuilds, see docs/development.md.
That path uses qemu + chroot to cross-compile gplan for ARM and needs
the gcc-avr / avr-libc toolchain.
W axis (auxcnc)
This fork adds a virtual W axis. See docs/AUX_W_AXIS.md for:
- G-code surface (
G28 W0,G1 W25, etc.) - The G-code preprocessor and hook architecture
- aux.json keys
- REST API (
/api/aux/*) - UI surface (jog row in Control, settings panel in Settings)
- Edge cases (ESP reboot mid-job, limit closed at home start, …)