You need take apart old fax machine, I don't have any photo of it before tear-down.
mine have 2 stepper motors
1 that move printer head, other move paper.
Step 1: Z Azis
my Z axis is a floppy drive that I cut in half and hot glue it on carriage.
Step 2: Assembly Hardware Part
Video is on Russian, I will add annotation to it soon.
1 arduino UNO
3 modules for stepper motors L298N
1 power supply 7.5v 1A
Step 3: Wiring
each motor module have 4 signals, Vin and 4 connectors for bi-polar stepper motor.
so arduino pins 2,3,4,5 goes to 1 steper
modue 6,7,8,9 second
and 10,11,12,13 -> third it must be Z motor
Step 4: Now the Fun Part, (software)
Software I copy pasted from this article
More information about the Mini CNC Plotter here (german, sorry):
My modification is on github
Software to send gcode: https://github.com/roboter/gctrl
I hope you like my tutorial, if you have any questions don't hesitate to ask!