With a working x, y and z axis I decided to buy a complete 3d extruder.
The Geeetech assembled MK8 extruder has a default 0.3 mm nozzle size and uses 1.75 mm filament. It comes with a stepper motor. I’ve chosen this extruder because of it’s size. It has the size of a Nema stepper and is flat at the bottom.
The extruder-carriage uses the same LM8UU bearings as the other axes. The fourth image shows the actual built without extruder. The last 3 images show details of the extruder-carriage. Starting with the blue belt holder. This one uses the same connection technique as the Y-axis. This one is smaller because it has to fit between the carriage and the X-axis.
Use tie wraps to attach the bearings.