I recently assembled a desktop PC from an APU, mobo, case, supply, drives, etc., courtesy of Amazon's amazing selection and reasonable prices, to get the greatest bang-per-buck. I added a front panel with USB ports, for a total of 4 up front (I wanted to make use of all of the USB ports provided by the mobo, and to avoid using a USB hub, in hopes of getting better performance when, for example, transferring a lot of data from one USB drive to another.) Although it's no gaming-PC, it has gobs of power and can for example transfer a Linux ISO from its SSD to its HDD in a few seconds. I put Kubuntu 16.04 (from ShopLinuxOnline.com) on it, mainly because I wanted to install certain KDE software (such as Kdenlive, which is excellent and apparently the only Linux video editor worth having at this point) without having to download enormous amounts of data via my metered internet connection. I ended up liking Kubuntu more than I expected because it's very polished and just works well.
However, when USB drives were plugged into the front of the PC, they were vulnerable to impacts from the top, bottom, and sides, and could end up being destroyed. So, I wracked my brains over how to protect the drives, and the USB ports/jacks, from such impacts. I'm fairly certain that I considered every possibility, and the result is shown in the attached photos, which are worth thousands of words, and in my case, dozens of revisions. Note how it wraps around the sides of the PC. I could stand on this thing without straining it, but I'd probably end up falling off and getting injured. The cover simply sits on top of the 2x4's when needed. The gaps around the front of the cover allow me to plug cables into the front panel, and to see the drive-activity LED, even when the cover is in place. They also make it easy to grab the cover to remove it. The top 1x3 was supposed to be flush with the top of the plywood, but I cut the side-1x3's too short. One of my criteria was easy assembly without any special hardware, so that it can be made from scrap wood and parts on hand without any special equipment. If your PC is ventilated in front, you could just make the frame wide enough to create gaps for air to get around the sides of the PC.
