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AMS Maintenance

AMS (Automatic Material System) is a precision system that requires regular maintenance to work reliably. The most common problems are a dirty filament path and moisture in the housing.

PTFE tubes

PTFE tubes transport filament from the AMS to the printer. They are among the first parts to wear out.

Inspection

Check PTFE tubes for:

  • Kinks or bends — impedes filament flow
  • Wear at connections — white dust around the inlets
  • Shape deformation — especially with CF materials

Replacing PTFE tubes

  1. Release filament from AMS (run unload cycle)
  2. Press in the blue locking ring around the tube at the fitting
  3. Pull out the tube (requires a firm grip)
  4. Cut new tube to the correct length (not shorter than the original)
  5. Push in until it stops and lock
AMS Lite vs. AMS

AMS Lite (A1/A1 Mini) has a simpler PTFE configuration than full AMS (P1S/X1C). The tubes are shorter and easier to replace.

Filament path

Cleaning the filament path

Filaments leave dust and residue in the filament path, especially CF materials:

  1. Unload all slots
  2. Use compressed air or a soft brush to blow out loose dust
  3. Run a piece of clean nylon or PTFE cleaning filament through the path

Sensors

AMS uses sensors to detect filament position and filament breaks. Keep sensor windows clean:

  • Gently wipe sensor lenses with a clean brush
  • Avoid IPA directly on sensors

Moisture

AMS does not protect filament from moisture. For hygroscopic materials (PA, PETG, TPU) the following is recommended:

Dry AMS alternatives

  • Sealed box: Place spools in an airtight box with silica gel
  • Bambu Dry Box: Official drying box accessory
  • External feeder: Use a filament feeder outside the AMS for sensitive materials

Moisture indicators

Place humidity indicator cards (hygrometer) inside the AMS housing. Replace silica gel pouches when above 30% relative humidity.

Drive wheels and clamping mechanism

Inspection

Check the drive wheels (extruder wheels in AMS) for:

  • Filament residue between teeth
  • Wear on gear teeth
  • Uneven friction when pulling manually

Cleaning

  1. Use a toothbrush or brush to remove residue between the drive wheel teeth
  2. Blow with compressed air
  3. Avoid oil and lubricant — the grip level is calibrated for dry operation

Maintenance intervals

ActivityInterval
Visual inspection of PTFE tubesMonthly
Cleaning filament pathEvery 100 hours
Check sensorsMonthly
Replace silica gel (dry setup)As needed (at 30%+ RH)
Replace PTFE tubesWhen visible wear is present