Heated Bed - MK3 Aluminium
The new MK3 Aluminium heated beds have a few advantages over the older MK2 and MK2B heated bed designs.
The aluminium backing in the MK3 acts as a thermal buffer, building up heat much more evenly than the older PCB designs.
Because of this aluminium layer, the MK3 is also flat enough to print directly on - no need for a separate piece of glass!
These heated beds are hooked up the same way as the older MK2 designs - the board accepts 12 or 24V power, simply solder your wires to the pads indicated.
There's space for SMD LEDs and a resistor, and a hole in the centre for a thermistor.
The board mounts the same way as the older designs - there's a screw hole in each corner in the same spacing as the MK2 boards, plus an extra screw hole between the solder pads to allow for 3-point mounting. 3-point mounting makes it much easier to get the bed levelled correctly, but your printer will need a matching screw hole in the right spot.