About this 3D model

A & B slide together and fit really nice, I've add two 3mm screwsfrom the bottom of A to B just to be sure. I also added the threechannels in part B, the outer most I placed LED's, the centerchannel delivers air. I've opened up the design so I can see the printing,and still get the cooling benefits. 40Fan-B-2 added, it's a bit balker, heaps cleaner inside for better airflow.