3D printers is good way to learn Modern CNC controllers, Electronic, Electrical and Mechanical - Mechatronics. Even better is hacking into old hardware, now you learn all the more. So, here is my attempt to build 3D printers from old printers we have had in our houses for decades.
The aim is to utilise 3 old printers, every part possible from them and buy parts needed to be bought. So, frame of aluminium will naturally be bought out. I build a frame from aluminium, unfortunately I caught very light aluminium sections and they obviously failed to achieve stability, so opted for steel rectangle pipes welded together.
Motors can be controlled using the motor controllers from the printer. However, they turned out to be too much of a hassle for me, so opted for new Arduino Mega and RAMPS. But, those who are comfortable with electronics, may easily opt for Arduino along with controllers from the old printers.