Step 1: Materials
-3/4" x 1/8" aluminum flatbar
-1" x 1/16" aluminum angle
-machine screws, washers, and nylock nuts
-1/2" weather stripping
The aluminum flatbar and angle can be found at hardware stores, I got mine at home depot.
Overall materials cost somewhere around $20.
The flatbar sections are about 20.25" long, They are bent so that the center length is about 13.25" long and the legs are 3.5" long.
I bent them by hand, the aluminum is pretty soft. I used a scrap piece of 4X4 and a hammer to help get a consistent bend.
You can then drill holes to match your hardware in the angle and in the flatbar.
I used my ps3 during these steps to ensure the parts would fit properly.
This is also a good time to see if all parts will fit together and holes line up before mounting the system.
At this stage I already drilled the holes for the lower angle and marked/drilled the holes for the top angle. Bolt the top angle through the cabinet (or whatever you are mounting it to). You can keep the lower angle bolted to the flatbar sections during installation.
To make the lock even stronger a flatbar section, backing plate can be used on the back side of the cabinet so that the nuts cannot be ripped out through the "wood" (I skipped this step).