HP DeskJet 3550 / 3845 Paper Feed Roller Gear Replacement

HP DeskJet 3550 / 3845 Paper Feed Roller Gear Replacement

This is a replacement gear for the main paper feed shaft (roller shaft) for HP DeskJet 3550 and HP DeskJet 3845 printers (may also fit other models using the same mechanism).

Over time, the original plastic gear cracks, loses its grip on the metal shaft, or strips its teeth. This 3D-printed part allows you to repair your printer instead of throwing it away.

Symptoms of a Broken Gear:

* No paper pickup: The printer claims it is out of paper, even though the tray is full.

* Slipping on the shaft: You can hear the motor spinning, but the rubber rollers or plastic ejector paws do not move because the gear spins freely on the metal axle.

* Paper jams / No ejection: The printer successfully prints but fails to release or eject the paper at the end, holding it on the roller.

Print Settings Recommendations:

* Material: PETG, Nylon, or Tough PLA (Standard PLA might wear out too quickly under mechanical stress).

* Infill: 100% (Solid) for maximum strength.

* Perimeters (Walls): At least 3-4 walls.

* Layer Height: 0.1mm - 0.12mm (for precise gear teeth profile).

* Support: Not required if printed flat-side down.

Installation Tip:

Clean the metal shaft from any grease and leftover plastic before pressing the new gear on. A drop of superglue or retaining compound can help secure it permanently to the shaft if the fit is too loose.