Step 1: 1 - Prepare the hub/cartridge
2. Drilled hole in the center of the cartridge, the hole is the same thickness as the male cable from the usb.
3. Holes for the female usb ports (only three, the fourth one will have a usb mini dongle instead). I started making these holes with a dremel but it was to clumsy so I used an old rusty knife instead, worked REALLY good. I'll never use a dremel for cuttting plastic again!
ps. unfortunally I broke my first hub, that's why there is black lines on the sides of the holes. The first one would fit, the second one I used are a bit smaller so now the lines are showing.. I'll clean it up with some chemicals later =p