About this 3D model

In order to maximize thermal transfer between the resistors and thermal block, the contact area between them must be maximized by making both surfaces as flat as possible. I was introduced to this trick through PC modding, more information can be found by googling "heat sink lapping." The picture of the resistors is to show that they are certainly not flat on the bottom, when the process is complete the surface should look uniform but not necessarily a mirror finish as with the heater block.