For the 3020, 3040, and 6040 series CNC Routers, there is a stand alone heater controller sold by MIB Instruments (based in China). This controller takes care of most of the necessary heating and monitoring needed to convert a CNC router to a 3D printer. The biggest problem I have encountered was that the unit was designed only for those who have an extra axis not currently used by their system. (i.e. A-axis) If you purchased from a cheaper reseller of the 3D routers you most likely do not have a compatible controller, at least without a little modification. These modifications will be discussed in another post. For now we will just discuss the heater controller made by MIB Instruments called the M3D-H2.
Here is a link to their website. They also have an eBay store where they sell all of their equipment.
http://www.mib-tech.com/
3D Printer page:
http://www.mib-tech.com/3d_printer.html
The "kit" is sold/advertised as a complete kit to convert your MIB Instruments 3020 CNC router to a 3D printer. It does not include everything you need, and the 2 components you do need to make a complete kit, are only sold separately on their eBay store.
Heater Controller & Heater Bed: (I paid $282.34, shipping included)
http://www.ebay.com/itm/321111260236
Filament Feed Stepper, Heater, & Thermocouple: (I paid $79)
http://www.ebay.com/itm/330943103747
I also purchase 2 1KG spools of filament. One PLA and one ABS so I can experiment with the different materials.
A dot-matrix LCD display is "glued" to the PCB. While this makes for a clean, single board installation, it's not so easy to replace if the back light goes out it you want to make any changes to the design.
I first impression was one of disgrace when I saw the hack-sawed heatsink that must've been pulled from a scrap bin. For the two most critical components on the board, the FET's that power the heaters, you would think they could put a little more effort into cooling.
The board is expandable. You could add two more thermocouples as well as 2 more heaters. I may throw together a schematic in the future to help explain this.
The microprocessor that controls everything is a PIC 16F866.
The thermocouple chip is a MAX6675 (U5).
A LM2575T (D3) switching regulator is used for ?
A IRF4905 (D8) ??? is used for?
A ND B1205S-1W DC-DC converter is used to isolate the control circuitry from the power circuitry.
The heater controller uses a 250W 24V switching power supply to power everything. Nothing special here.
I may revise this in the future, it's sort of a draft, but I want to get it posted and out there so you all can read it.