MakerBot Cupcake Heated Build Platform v2.0

This is a new and improved heated build platform. It is lightweight, compact, lower cost, and sexier than the old heated platform. It is also easier to put together and simpler in construction.

The major breakthrough on this board is twofold:

1. We use a PCB for both the heater element and the support circuitry.
2. We use a lasercut aluminum heat spreader for uniform temperature.

After a bit of trial and error, we came up with an optimum trace resistance of about 4.5 ohms which gives u