The principal of 3D Printing is very old. Malleable material is put into place to harden out. The way to do this depends on the material used. Concrete, metal, powder and plastics and even more is possible. Metal is usually handled as powder, heated by a laser. Powder or liquid can be Infrared or Ultraviolet hardened. Concrete is extruded the hard way.
The common hobby-3D Printers use plastics, PLA or ABS. More plastics are created with divined properties. These materials are heated and extruded in place, The smaller the extruding, the higher the resolution of the printer, the nicer prints will be. But, printing takes time……..
Building a working extruder for PLA and ABS was the first thing to do. The principal is quite simple. Plastic is pushed through a heated nozzle. The heater I use is a small aluminium block with a 4 Ohm / 4 Watt resistor glued in with kit. Switched by a MOSFET it can reach 250 degrees celsius.
To make the extruder move I used my CNC4 Router table. Because the CNC4 Router table was MCU/USB controlled, I had to add routines in the software, to work with GCODE.
The results were great at this point, so I could start building a frame. One problem was the weight of the stepper motors. I would not want them to be included in one of the axis, so……..
On the internet I found a picture of a Cartesian Motion Platform.
With this design it is possible to keep the motors static, not on the axes and that would save weight. Less weight on the extruder can give higher speed, right?
Gathering second hand aluminium profiles made it possible to create a frame.
All electronics are completely self designed and made. The Steppers are controlled by a PIC18F4550 MCU which gets its information via USB. The extruder and table temperature are controlled by a PIC18F14K50 and are always adjustable with potentiometers.
The software is created in VB6 and was copied and modified from the code for the CNCTable.
Three extruders have been produced, 0.8mm, 1.5 mm and recently a 0.4mm.
Then I found a way to read files on SD cards with a PIC18F4550 and so I ordered a few serial TFT displays on Ebay with a SD socket.
To weld multiple large parts together, I created a hand pistol.