The PDF version of this article has photos for your ease of reference

What Does this Do Anyway?

This new system replaces the entire plunger and plunger housing that came with your bot. It is designed to be strong, easy to use and never need adjusting !


It is also designed to never need adjusting and to provide constant pressure against the filament for good flow rates


How Do I Fit It?

It comes with the screws, bearing and spring in place.


1 Get the stepper motor off your machine

First—unload filament from the extruder and turn off the machine


Then remove the stepper motor (and existing plunger housing from your machine). You will need to unscrew the front fan screws, and pull the fan guard, fan, spacers and aluminium heat sink forward and off the extruder motor.


Now carefully slide the stepper motor backwards and unclip the power cable from the motor. Now undo the 2 screws that hold on the current plunger assembly and remove the two black pieces of the plunger housing. 


2. Fit the Spring Housing

Separate Piece 1 and 2 from your new filament feeder system and screw Part 1 to the stepper motor. Yes this screw is small—but adequate ;) It is really important that it is popped in against the  circle step up on the stepper motor and flush to the stepper. Make sure there is a fine gap between the drive wheel and the spring housing. It is only small but important.


3. Attach the arm

On the screw mount of the arm is a plug that allows the arm to pivot. It is VERY important to make sure that this is pushed into the Spring housing and that the plastic parts are flush once screwed  together.


It is also important to make sure the bearing is now nestled into the teeth area of  the drive wheel on your stepper motor; and not against the edges. It does not even mater if the bearing does not spin, but it does if it is pressed against the edges of the drive wheel.


Check the Endstop

Sometimes in this process you may have slightly tilted the stepper so it does not activate the x axis stepper motor. Turn the machine on and slide the extruder all the way to the right. Does the x axis endstop light come on? If not you may need to loosen the screw on the endstop circuit board and pivot it very slightly so the endstop is activated (the button is pressed) when the extruder moves over to the right.


About the lever to the right of the arm

You can press down on this to load filament and then release again. DO NOT grab the leaver with pointer finger and put your thumb under the motor for leverage—you will end up grabbing the hot nozzle and burning yourself!


BilbyCNC hopes you found this helpful. Please visit if you need further assistance