About this 3D model

PCB heated bed. I'm working on this idea for nearly two months, inspired by http://www.neufeld.newton.ks.us/electronics/?p=864 . UPDATE ------ tested at 110W and its working flawlesly, gives 108°C in few mins Now I'm working on great mounting solution This is V4 -------- - 22x20cm hated area - you can select what resistance you want 1.3ohms (110W at 12V) or 21ohms - you dont need any steel or aluminium on top, just plane kapton tape (I'm testing it at 21ohms setup with 55V PSU which gives me 144W and about 110-120°C, will test with 12V soon and I'll give a report)