Vacuum pump
The vacuum unit that lifts pellets from the bucket up through the corrugated tube into the Hopper. Switched on/off by the firmware via the Feeding socket on the power box (under the panel box, right side).
Function
Section titled “Function”- Sucks pellets from a floor-level bucket up to the hopper
- Cycles automatically when the hopper level sensor signals empty
- Connected via the corrugated tube
Location
Section titled “Location”Standalone unit, typically placed near the printer with the corrugated tube routed up to the hopper. Power cable plugged into the Feeding socket on the power box (under the panel box, right side — see Power outlets (power box)).
Specifications
Section titled “Specifications”| Parameter | Value |
|---|---|
| Voltage (EU) | 220–240 V |
| Voltage (US / non-EU) | 110 V (different model) |
| Power | ~1000–1200 W typical |
| Max tube length | 1.5 m recommended |
Critical operating rule — button must stay ON
Section titled “Critical operating rule — button must stay ON”Correct setup:
- Plug the vacuum into the Feeding socket on the power box (under the panel box, right side)
- Turn the vacuum unit’s own button to ON — leave it there permanently
- The printer will cycle the socket automatically during printing
If the vacuum button is OFF, the hopper will run empty mid-print with no warning until the printer beeps “material absent”.
How it works
Section titled “How it works”- Hopper level sensor detects low pellet level
- Firmware activates the feeding socket on the power box (powers the vacuum)
- Vacuum pulls air from the hopper, creating suction in the corrugated tube
- Pellets are lifted from the bucket to the hopper
- After a fixed cycle time, vacuum stops
- Pellets settle in the hopper; cycle repeats when needed
Bucket placement: keep the intake end of the corrugated tube submerged inside the pellet bucket at all times. If the tube pulls above the pellet surface, only air is drawn and no pellets move.
Maintenance
Section titled “Maintenance”- Weekly: check that the corrugated tube is tightly clamped at both ends
- Monthly: open the vacuum filter and clean accumulated dust / fines
- As needed: empty the bucket of fines that don’t get sucked up
- Annually: inspect the motor brushes (if present) and overall wear
Known issues
Section titled “Known issues”- Hopper suction problems — the most common feeding-related complaint
- Current spike during the suction cycle can cause undervoltage → see Klipper MCU communication lost
- Vacuum running but no pellets moving → almost always a leak at the hopper-tube joint
Test it works
Section titled “Test it works”- Open the hopper
- Manually trigger the vacuum from the printer display (Feeding toggle / test button)
- You should hear strong suction and feel airflow at the tube end
- Pellets should rise within a few seconds
- If no airflow → check power, fuses, and the test button on the vacuum unit itself
Recommended setup
Section titled “Recommended setup”- Bucket close to the printer — the shorter the tube, the better
- Tube straight or always rising — no sagging or U-shaped sections
- Tube length max 1.5 m — longer means flat or oily pellets get stuck
- Dedicated mains circuit — vacuum current spikes can crash the printer if shared with other equipment