Custom Snapmaker U1 Firmware

Klipper Tweaks

Advanced experimental tweaks for Klipper stepper motor driver configuration. These settings can only be configured via the Firmware Configuration web interface under Settings → Tweaks.

Warning: These are experimental features that modify low-level stepper driver parameters. Use with caution and monitor your printer carefully after enabling.

TMC AutoTune

Applies optimized stepper motor driver settings for TMC2240 drivers.

What it does:

• Optimizes PWM settings for quieter operation
• Configures StallGuard and CoolStep parameters
• Adjusts timing parameters for better heat management
• Fine-tunes driver parameters for improved performance

Risks:

• May cause motors to overheat if cooling is insufficient
• Could result in reduced torque or skipped steps under heavy load
• Incorrect settings may affect print quality
• Changes low-level driver parameters that override defaults

Recommendation:

• Monitor motor temperatures during first use
• Test with simple prints before production work
• Revert to disabled if you experience issues

Configuration: This feature can only be configured via Firmware Configuration web interface. Manual configuration is not supported.

TMC Reduced Current

Lowers the stepper motor run current from 1.2A to 1.0A for X and Y axes.

What it does:

• Reduces X and Y axis motor current to 1.0A
• Lowers motor heat generation
• Results in quieter motor operation

Risks:

• May cause skipped steps under heavy load or fast movements
• Could result in layer shifts on demanding prints
• May reduce positioning accuracy under high acceleration

Recommendation:

• Monitor print quality after enabling
• Watch for layer shifts or positioning issues
• Disable if you experience motion problems

Configuration: This feature can only be configured via Firmware Configuration web interface. Manual configuration is not supported.

Max Speed

Raises the XY motion limits and speeds up tool changes. Motion settings only — no stepper driver registers are changed, so sensorless homing is unaffected.

Both tiers run the printer above the motion limits Snapmaker ships it with — the Stock column below is the rated configuration, and every value to the right of it is beyond what the machine is specified for. These numbers are community-tested, not vendor-validated, and the extra speed is paid for in wear.

Values derived from @JNP-1.

Two tiers:

	Stock	Balanced	Aggressive
Max XY velocity	500 mm/s	600 mm/s	750 mm/s
Max acceleration	20000 mm/s²	22000 mm/s²	25000 mm/s²
Tool change speed	400 mm/s	550 mm/s	700 mm/s
Slow dock-entry speed	60 mm/s	40 mm/s	60 mm/s
Dock grab speed	10 mm/s	30 mm/s	50 mm/s
Tool change acceleration	5000 mm/s²	12000 mm/s²	25000 mm/s²

Which one: start with Balanced and move to Aggressive only once tool changes are reliable. Balanced’s dock-entry speed is deliberately below stock — that move is short, so a slightly slower dock approach is expected, not a regression.

Requirements:

• Dock positions are calibrated correctly
• Belt tension is correct
• Input shaper is calibrated for your printer (run SHAPER_CALIBRATE)
• Tool changes are already reliable with the stock configuration

Risks:

• Accelerated wear from running the printer above its rated limits
• Crashes into the tool docks if dock positions are off
• Layer shifts and skipped steps under heavy load
• Higher driver and motor temperatures
• Ringing and other quality artifacts if input shaper is not calibrated

Recommendation:

• Calibrate the printer fully before enabling
• Start with Balanced and a small test print, and watch the first tool changes
• Disable if you see dock alignment problems or layer shifts

Note: This tweak cannot be combined with TMC Reduced Current — running the X/Y motors at 1.0A with these raised speed limits is untested. Firmware Config refuses that combination and tells you which tweak to disable first. TMC AutoTune can be used alongside Max Speed; the two no longer change any setting in common.

Configuration: This feature can only be configured via Firmware Configuration web interface. Manual configuration is not supported.

Object Processing for Adaptive Mesh

Enables object processing in Moonraker’s file manager to support adaptive mesh features.

What it does:

• Processes gcode files to extract object information
• Generates boundaries for adaptive mesh leveling
• Allows per-object print settings and controls

Risks:

• Can cause very long processing times for large gcode files (> 100MB)
• May result in extended delays when uploading files
• Snapmaker Orca may stay at 100% for a long time when sending prints
• High memory usage during file processing
• Can cause delays before prints can start

Important:

• Enabling this setting alone is not enough to use adaptive mesh
• You must also update your slicer start gcode to use: BED_MESH_CALIBRATE ADAPTIVE=1
• This tells Klipper to only mesh the area where objects will be printed

Recommendation:

• Preferred approach: Enable Exclude Object in your slicer settings instead of this option
• Slicer-generated object labels are more reliable and don’t require server-side processing
• Only enable Moonraker object processing if your slicer doesn’t support exclude object
• Disable if you frequently print large gcode files
• Monitor file upload times after enabling
• Consider splitting large models into smaller prints if processing is too slow

Configuration: This feature can only be configured via Firmware Configuration web interface. Manual configuration is not supported.

How to Configure

1. Open the printer’s web interface (Fluidd or Mainsail)
2. Navigate to Firmware Config in the menu
3. Go to Settings → Tweaks
4. Select the desired option for each tweak
5. Confirm the warning dialog
6. Klipper will automatically restart to apply changes

Changes take effect immediately after Klipper restarts (no reboot required).

Technical Details

These tweaks work by adding or removing configuration files from /oem/printer_data/config/extended/:

• klipper/tmc_autotune.cfg - TMC AutoTune parameters
• klipper/tmc_current.cfg - Reduced current settings
• klipper/10_max_speed.cfg - Max Speed motion limits and tool change speeds (either tier installs to this one file)
• moonraker/object_processing.cfg - Moonraker object processing settings

These files are automatically included by the main printer configuration if present. Manual editing of these files is not recommended as they will be overwritten by the Firmware Configuration interface.