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Automatic feeding system

The G1 feeds itself: a vacuum draws pellets from the material source into the hopper whenever the level drops, so a print never waits on a hand with a scoop. This page is the map of that system — each stage links to its component note.

Official walkthrough: How the G1 Automatic Feeding System works (4:06).

The chain

Section titled “The chain”
The G1 feed line from dryer to extrusion screw Outside the printer, pellets leave the D1 dryer tank through a manual guillotine and the pellet gate, then travel through a white corrugated section, a smooth rigid grey pipe and a second corrugated section to E17 on top of the hopper. The vacuum pump is connected to the second port on E17 and draws air through the line; air enters at the pellet gate and is what carries the pellets. Inside the extruder the material passes the filter and gasket into the hopper, where a capacitive probe watches the level, and the E1 auger pushes it into the E0 extrusion screw. OUTSIDE THE PRINTER D1 tank Guillotine Pellet gate Rigid grey pipe E17 dried material closed when idle pickup filter static run hopper cap corrugated corrugated air enters here the vacuum pulls it through the line — the airflow is what carries the pellets INSIDE THE EXTRUDER Filter + gasket Hopper — E04 Auger — E1 Screw — E0 keeps pellets out of the air probe watches the level pushes to the screw melts and extrudes E17 is where the line enters the machine — the material continues on the lower row
The feed line end to end. Material moves left to right along each row; the accent arrow marks where air enters, which is what actually conveys the pellets.
StageWhat it doesDetail
D1 dryerHolds and dries the materialDryer
GuillotineManual slide, closed while drying and whenever the printer is offPellet gate and guillotine
Pellet gatePickup filter: stops gravity feed into the tube and admits the air that carries the pelletssame
Feed lineCorrugated → rigid grey pipe → corrugated, always risingCorrugated tube
E17 + filter + gasketCap with TANK and VACUUM ports; the filter keeps pellets out of the vacuum lineHopper
Hopper (E04)~500 g buffer, watched by a capacitive probeLevel probe and the feeding cycle
Vacuum pumpStandard shop vacuum on the FEEDING socket, switched by the feeding boardVacuum pump
Auger — E1Pushes pellets into the screw inletThe two extruder steppers
Screw — E0Melts and extrudesExtruder screw

The capacitive level probe threaded into the side of the red hopper body, its cable running away to the left

The probe that starts and stops the cycle below, seen in the hopper wall.

The cycle, in one paragraph

Section titled “The cycle, in one paragraph”

The capacitive probe in the hopper wall reads on while material covers it. When the level drops the probe goes off and — with FEEDER enabled — the feeding board runs the vacuum for about 3 seconds, waits 5, checks again, and repeats up to four rounds. Material arriving covers the probe and the cycle stops; four dry rounds instead trigger the buzzer (3 s on, 17 s off). Normal cadence is one feeding event every 10–20 minutes depending on flow. The logic runs on a dedicated Arduino Nano on the Ginger.Feeding board in the panel box, not in Klipper — source: G1-AutoFeeding.

FEEDER is off when the printer powers up; the START_PRINT macro switches it on. An idle machine with FEEDER off is not a fault.

Operating rules

Section titled “Operating rules”

The five rules that keep the system running, each learned the hard way in support:

  1. The vacuum’s own button stays ON, always. The printer switches its socket
  2. Open the guillotine when a print starts, close it while drying and whenever the machine is idle
  3. The line must always rise — anywhere pellets can fall by gravity, they pile up and plug the tube
  4. Filter and gasket must be in place whenever the hopper is reassembled, and the gasket has a direction
  5. The hopper stays closed — suction only exists because E04 is sealed

When material stops arriving

Section titled “When material stops arriving”

Work through Hopper suction problems — it starts with the fastest checks (guillotine, then the E17 joint) and ends with the mains-capacity case. The buzzer means four rounds of suction found nothing: blocked tube, vacuum off at its own switch, or a loose probe connector.

Emptying the system

Section titled “Emptying the system”

For a material change, empty in this order: hopper off (both knobs, FEEDER off first), tip it out, then run the vacuum to empty the pipes, then purge the extruder. Full steps: Taking the hopper off.