How to build a $20 47A power supply

[silentbob343]

Almost finished with mine,

Was also wondering if I should use rubber grommets on my aluminum angle to reduce the possibility of a short should the post shift and contact the aluminum.

Here is a picture to demonstrate what I am referring to. Once the back half is on and the nuts are snugged over the post it seems secure, but I would hate for the posts to touch the edges of those holes if I were drop the PS or have some other jarring force act on it.