Light well cover now storm secure

I had a big light well to cover from rain, so I decided to take a plastic-plate. - To make this storm secure and easy to handle I constructed some items.

You can download the knob right here: http://www.thingiverse.com/thing:1523670

You will need
1 Plastic-plate
1 Square aluminium rod (15mm) to cut in 4 pieces, hight like needed
4 M3 Screws and bolts (to fix the rod)
4 M6 Screws and bolts (to fix the knob)
16 M6 Screws with dowel